Flooding
Ensemble forecast
Source: The Hindu
Gs3: Disaster Management
Context: India needs to shift to ensemble weather and flood forecast model to achieve better accuracy in flood forecasting.
What is the significance of using Ensemble forecast?
Deterministic forecast model | Ensemble forecast |
· Deterministic forecast model merely indicates “Rising” or “Falling” above a water level at a river point. · In this model,there is no idea of the area of inundation, its depth, and when the accuracy of the forecast decreases at 24 hours and beyond
| · It gives probability-based estimation as to different scenarios of water levels and regions of inundation. · For example, it can indicate the probability like, the chances of the water level exceeding the danger level is 80%, with likely inundation of a village nearby at 20%.
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· It provides a lead time of just 24 hours | · It provides a lead time of 7-10 days ahead.
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· Since the end users (district administration, municipalities and disaster management authorities) receive such forecasts with very less “Lead time” and have to act quickly, flood forecast becomes less accurate. | · It helps local administrations with better decision-making and helps them to get prepared better in advance.
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· India has recently shifted towards -Deterministic forecast model | · The United States, the European Union and Japan have shifted towards Ensemble flood forecasting along with “Inundation modelling”. |
What are the shortcomings with India’s flood forecasting?
Multiple agencies:
- The India Meteorological Department (IMD) issues meteorological or weather forecasts while the Central Water Commission (CWC) issues flood forecasts at various river points.
- Therefore, the advancement of flood forecasting depends on how quickly rainfall is estimated and forecast by the IMD and how quickly the CWC integrates the rainfall forecast with flood forecast.
- It also is linked to how fast the CWC disseminates this data to end user agencies.
- This complicated arrangement reduces the “Lead time”.
Obsolete methods:
- Most flood forecasts at several river points across India are based on outdated statistical methods that enable a lead time of less than 24 hours.
- It renders the India’s flood forecast driven by Google’s most advanced Artificial Intelligence (AI) techniques ineffective.
Not uniform across India:
- A recent study shows that, India has only recently moved to use hydrological or simply rainfall-runoff models not all, but in specific river basins.
Impact:
- Therefore, outdated technologies and a lack of technological parity between multiple agencies and their poor water governance decrease crucial lead time.
- Forecasting errors increase and the burden of interpretation shifts to incompetent end user agencies. The outcome is an increase in flood risk and disaster.
What is the way forward?
- The IMD has already started testing and using ensemble models for weather forecast through its supercomputers (“Pratyush” and “Mihir”).
- Yet, the forecasting agency has to adapt with advanced technology and need to achieve technological parity with the IMD in order to couple ensemble forecasts to its hydrological models.
- The IMD has to modernise the telemetry infrastructure along with raising technological compatibility with river basin-specific hydrological, hydrodynamic and inundation modelling.
- It also needs to trains its technical workforce to get well versed with ensemble models and capable of coupling the same with flood forecast models.
- It is only then that India can look forward to probabilistic-based flood forecasts with a lead time of more than seven to 10 days that will place India on par with the developed world.
Cyclones
How Tropical cyclone are formed?
News: Cyclone Burevi has weakened into a deep depression as its interaction with a landmass in Tamil Nadu has slowed its movement and intensity.
Cyclonic disturbances are rapid weather systems, which include weather depressions, deep depressions, and tropical cyclones (of severe, very severe, extremely severe, and super cyclonic storms depending on their intensity).
What are Tropical cyclone Burevi ?
Tropical cyclones are violent storms that originate over oceans in tropical areas and move over to the coastal areas bringing about large-scale destruction caused by violent winds, very heavy rainfall, and storm surges.
Cyclones create a whirl in the atmosphere with very strong winds circulating around it in an anti-clockwise direction in the Northern Hemisphere and in a clockwise direction in the Southern Hemisphere.
The pressure gradient falls towards the center from all directions and therefore winds try to converge towards the center from all directions. The air blows inwards in an anticlockwise direction in the northern hemisphere and clockwise in the southern hemisphere.
Conditions for formation of Cyclones
The conditions favorable for the formation and intensification of tropical storms are:
- A consistent source of heat as tropical cyclones are thermally induced low-pressure systems.
- Large sea surface with a temperature higher than 27° C which is possible only during the late summers i.e. September, October, and November
- Presence of the Coriolis force.
- Small variations in the vertical wind speed.
- A pre-existing weak low-pressure area or low-level-cyclonic circulation;
- Upper divergence above the sea level system.
Structure of Tropical Cyclone
The structure of a Tropical Cyclone is typically a massive cumulonimbus cloud with rapidly rising air spiraling upwards at the margins of the eye. An eye is a region of calm with subsiding air. Around the eye is the Eyewall, where strong spiraling winds ascends and the height can reach up to the tropopause.
Tropical cyclones are formed by the following parts:
Eye:
The eye is the center of cyclones which is characterized by a calm area, sinking, and light wind. The eye is the calmest part of the Cyclone structure.
Conservation of angular momentum and centrifugal force are the reasons behind its formation.
Eyewall:
A band around the eye of the greatest wind speed, where clouds reach the highest and precipitation is the heaviest. The heaviest wind damage occurs where a hurricane’s eyewall passes over land.
Rain bands:
Curved bands of clouds and thunderstorms that trail away from the eyewall in a spiral fashion. These bands are capable of producing heavy bursts of rain and wind. Sometimes gaps are found between spiral rain bands, where no impact (wind or rain) of cyclones are found.
Formation of Tropical Cyclones
- As mentioned in the conditions, air temperature higher than 27° C with an abundant and turbulent transfer of water vapor to the overlying atmosphere (air) by evaporation is required for the formation of Cyclones, which is facilitated by direct insolation.
- As the low-pressure area is created over sea pockets and high pressure on the surrounding areas, air starts to flow from the high-pressure area to low-pressure pockets.
- The Coriolis force causes the wind to spiral around a low-pressure area. As the presence of Coriolis force is negligible in the equatorial belt between 5 degrees north and 5 degrees south latitudes, hence cyclonic systems do not develop in this region.
- Heated sea surface starts to heat the air over that leading to air moving up and away from the ocean surface due to convection, it leaves less air near the surface. Cool Air from the surrounding areas rushes towards the empty area to fill it, which after reaching there gets heated and picks moisture and starts rising upwards. It creates the cycle of air moving in and up.
- As the moist air rises up, it starts cooling with the altitude (temperature falls with the height), and the process of condensation starts. It results in the release of the latent heat of condensation. The latent heat of condensation is what drives the storm and leads to the formation of clouds.
- The energy that intensifies the storm, comes from the condensation process in the towering cumulonimbus clouds, surrounding the center of the storm (Eye).
- With the increasing altitude, the air cools down to an extent at tropopause where it fails to rise any further and starts to diverge outside horizontally.
- The whole system of clouds and wind spins and grows, fed by the ocean’s heat and water evaporating from the ocean surface. As the storm system rotates faster and faster, an eye forms in the center.
- A mature tropical cyclone is characterized by the strong spirally circulating wind around the center, called the eye. The diameter of the circulating system can vary between 150 and 250 km.
- Rain bands regions with cumulonimbus clouds are created, facilitating intense rainfall in that region. Cloud formation is dense at the center and density decrease towards the outside.
Conditions that slow or end Cyclones
- With a continuous supply of moisture from the sea, the storm is further strengthened. On reaching the land the moisture supply is cut off and the storm dissipates. The place where a tropical cyclone crosses the coast is called the landfall of the cyclone.
- Another condition that slowdown or ends a Cyclone is when dry, cool air is suddenly present in the system, which reduces the possibility of convection to keep the storm going.
Why More Cyclones are formed in Bay of Bengal?
There are other coastlines around the world that are vulnerable to surging storms – the Gulf Coast of Louisiana, for example – but the “north coast of the Bay of Bengal is more prone to catastrophic surges than anywhere on Earth”.
Both the Bay of Bengal and the Arabian Sea are prone to Cyclonic storms, but Cyclonic activities are more intense and frequent in Bay of Bengal Compared to the Arabian Sea
- High sea surface temperatures along with high humidity due to higher rainfall in the Bay of Bengal, triggers extremely strong cyclones.
- Sluggish winds, along with warm air currents in the Bay of Bengal keep temperatures relatively high.
- The supply of constant inflow of fresh water from the Ganga and Brahmaputra rivers makes it impossible for the warm water to mix with the cooler water below.
- Cyclonic winds easily move into the Bay of Bengal due to the presence of moisture source from rivers and the absence of any large landmass unlike the Arabian Sea, where Cyclones usually weaken due to the presence of Western Ghats.
- Whereas Arabian Sea receives stronger winds that help dissipate the heat, and the lack of constant fresh water supply helps the warm water mix with the cool water, reducing the temperature.
Classification of storms
Indian Meteorological Department (IMD), which classifies the low pressure systems in the Bay of Bengal and the Arabian Sea on the basis of capacity to damage, which is adopted by the WMO.
Benefits of Tropical Cyclones:
Although Tropical cyclones are known for the destruction they cause, when they strike, they also bestow certain benefits to the climatic conditions of that area such as
- Relieve drought conditions: By bringing rain to the coastal areas, cyclones relieve the drought-like conditions in the surrounding areas.
- Maintain equilibrium in the Earth’s troposphere: They Carry heat and energy away from the tropics towards temperate latitudes, thus helps in maintaining an equilibrium of the troposphere.
- Cyclones help in maintaining a relatively stable and warm temperature worldwide.
Causes of destruction caused by Cyclones:
There are three elements associated with cyclones that cause destruction during its occurrence. These are:
Strong Gusts/Squall:
- These are very strong winds that accompany a cyclonic storm damages installation, dwellings, communications systems, trees, resulting in loss of life and property.
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Torrential rains and inland flooding:
- Torrential rainfall (more than 30 cm/hour) associated with cyclones is another major cause of damages.
- Unabated rain gives rise to unprecedented floods.
- Rain is a serious problem for the people which become shelterless due to cyclone.
- Heavy rainfall from a cyclone is usually spread over a wide area and causes large-scale soil erosion and weakening of embankments.
Storm Surge:
- It can be defined as an abnormal rise of sea level near the coast caused by a severe tropical cyclone;
- Seawater inundates low-lying areas of coastal regions drowning human beings and life stock, causes eroding beaches and embankments, destroys vegetation, and leads to a reduction of soil fertility.
Apart from these Cyclones also create destructions such as:
- Sudden Change in Regional climate: The ability of cyclone to bring in warmer air is high. So, the elderly and children in those areas have a high vulnerability to develop heat-related problems such as heat strokes.
- Loss of Livelihood: The majority of the coastal people generally depend on fishing which is completely halted by cyclones.
- Loss of economy: The economic loss is in multifront from infrastructure loss, relief packages to people, etc.
Government Initiatives:
- Government is carrying out a National Cyclone Risk Mitigation Project (NCRMP) with the help of the World Bank to upgrade cyclone forecasting, tracking, and warning systems in India
- Government is also implementing the Integrated Coastal Zone Management Project (ICZMP) to improve national capacity for the implementation of comprehensive coastal management in India.
- Government also separated Structural(includes construction) and non-structural measures for effective disaster management of cyclones
- Solutions:
- The government should consider the NDMA Guidelines for the management of cyclones:
- Ensemble Warning System(EWS): Establish EWS involving observations, predictions, warnings, and customized local level advice for decision-makers (national, state, district level) to manage the impact of the cyclone (Read more about EWS)
- Commissioning of Aircraft Probing of Cyclone (APC): Guidelines calls for the combination of manned and Unmanned Aerial Vehicles (UAV) for critical observational data gaps.
- Cyclone Disaster Management Information System (CDMIS): Establishing a comprehensive department for coverage of all management information and provide online services to the departments of Disaster management.
- Specifying the roles and responsibilities in institutionalizing Cyclone risk mitigation with Developmental planning.
- Community-Based Disaster Management (CBDM): Guidelines asked to launch such activities in all villages of the 84 districts vulnerable to cyclones.
Way forward:
- With the adverse Climate Change risks posted by IPCC reports the only option for India is to better preparedness for the disaster with better urban planning, community awareness, etc.
Cyclone Burevi
News: Cyclone Burevi is heading towards the Tamil Nadu(TN) coast after crossing Sri Lanka.
Facts:
- Cyclonic Burevi: It is a tropical cyclone formed over southwest Bay of Bengal.It is expected to bring heavy rainfall over south Tamil Nadu and south Kerala.
- Named by: The name “Burevi” was suggested by the Maldives.
Additional Facts:
- Tropical Cyclones: These are storms that originate and intensify over warm tropical oceans.They are intense low pressure areas with very strong winds circulating around it in anti-clockwise direction in the Northern Hemisphere and in clockwise direction in the Southern Hemisphere.
- Different Names: Tropical Cyclones are known by different names in different regions:
- Cyclones in Indian Ocean
- Hurricanes in Atlantic
- Typhoons in Western Pacific in South China Sea
- Willy-Willies in Western Australia
- Conditions: The conditions favourable for the formation and intensification of tropical cyclones are:
- Large sea surface with temperature higher than 27° C;
- Presence of the Coriolis force enough to create a cyclonic vortex
- Small variations in the vertical wind speed;
- A pre-existing weak low-pressure area or low-level-cyclonic circulation is must for cyclone formation in tropics
- Upper divergence above the sea level system
Cyclone Nivar: All about tropical cyclones
This article has been created based on The Hindu Editorials: Storm warnings: On weather forecast and Cyclone Nivar appeared on 27th November 2020.
Introduction
According to the India Meteorological Department (IMD), Cyclone Nivar, which crossed the TN coast as a very severe cyclonic storm with wind speeds of 120 kmph and rain-filled, further weakened as it moved inland.
The storm system is likely to move northwestwards and weaken into low pressure. Subsequently, Cyclone Nivar weakened into a cyclonic storm and further into a deep depression, centered about 50 km west-southwest of Tirupati.
Cyclone Nivar is the second cyclone to form over the Bay of Bengal this year after Super Cyclone Amphan.
Read about Amphan and few basics in ForumIAS blog by clicking here
India Meteorological Department (IMD)
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What are Tropical Cyclones?
They are violent storms that originate over oceans in tropical areas and move over to the coastal areas bringing about large-scale destruction caused by violent winds, very heavy rainfall and storm surges.
- Conditions: The conditions favourable for the formation and intensification of tropical cyclones are:
- Large sea surface with temperature higher than 27° C;
- Presence of the Coriolis force enough to create a cyclonic vortex
- Small variations in the vertical wind speed;
- A pre-existing weak low-pressure area or low-level-cyclonic circulation is must for cyclone formation in tropics
- Upper divergence above the sea level system.
Vulnerability of India to Cyclone:
- Indian sub-continent is the worst affected region of the world, having a coast line of 7516 kms. (5400 kms along the mainland, 132 kms in Lakshadweep and 1900 kms in Andaman and Nicobar Islands) is exposed to nearly 10% of the world’s Tropical Cyclones.
- 40% of the total population lives within 100 km of coastline.
- Four States (Andhra Pradesh, Odisha, Tamil Nadu, and West Bengal) and one UT (Pondicherry) on the East Coast and One State (Gujarat) on the West Coast are more vulnerable to cyclone disasters
Benefits of Tropical Cyclones:
Although Tropical cyclones are known for the destruction they cause, when they strike, they also bestow certain benefits to the climatic conditions of that area such as
- Relieve drought conditions: By bringing rain to the coastal areas, cyclones relieve the drought like conditions in the surrounding areas.
- Maintain equilibrium in the Earth’s troposphere: They Carry heat and energy away from the tropics towards temperate latitudes, thus helps in maintaining equilibrium of the troposphere.
- Cyclones help in maintaining a relatively stable and warm temperature worldwide.
Causes of destruction caused by Cyclones:
There are three elements associated with cyclones that cause destruction during its occurrence. These are:
- Strong Gusts/Squall:
- These are very strong winds that accompany a cyclonic storm damages installation, dwellings, communications systems, trees, resulting in loss of life and property.
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- Torrential rains and inland flooding: Torrential rainfall (more than 30 cm/hour) associated with cyclones is another major cause of damages.
- Unabated rain gives rise to unprecedented floods.
- Rain is a serious problem for the people which become shelter less due to cyclone.
- Heavy rainfall from a cyclone is usually spread over wide area and cause large scale soil erosion and weakening of embankments.
- Storm Surge: It can be defined as an abnormal rise of sea level near the coast caused by a severe tropical cyclone;
- Seawater inundates low-lying areas of coastal regions drowning human beings and life stock, causes eroding beaches and embankments, destroys vegetation, and leads to a reduction of soil fertility.
- Apart from these Cyclones also create destructions such as
- Sudden Change in Regional climate: The ability of cyclone to bring in warmer air is high. So, the elderly and children in those areas have a high vulnerability to develop heat-related problems such as heat strokes.
- Loss of Livelihood: The majority of the coastal people generally depend on fishing which is completely halted by cyclones.
- Loss of economy: The economic loss is in multifront from infrastructure loss, relief packages to people, etc.
Challenges in Cyclones Management:
- Bare minimum Technology: At the terminal-end generally lacks the equipment and communication back-up to deal with the situation effectively.
- Lack of grass root level participation: There is a wider awareness gap is there between disaster management from people’s end.
- Multiple agencies: The IMD issues meteorological or weather forecasts while the Central Water Commission (CWC) issues flood forecasts at various river points. But cyclones bring the combination of problems. Before the integration of data people on the ground lost the “golden time”.
- Low data: The government has not measured the peak flows in the rivers and canals to plan remedies and also not documented data on annual flooding patterns.
- Absence of land use norms has spawned an amorphous housing sector characterized by inflated, speculative prices but no foundation of civic infrastructure.
- Poor Urban planning: Many Indian cities lacks poor urban planning which is highlighted by floods in Chennai and Mumbai.
- Climate Change: There are many proven records that exist between the link between the higher frequency of disaster and climate change.
Government Initiatives:
- Government is carrying out a National Cyclone Risk Mitigation Project (NCRMP) with the help of the World Bank for upgrade cyclone forecasting, tracking and warning systems in India
- Government is also implementing Integrated Coastal Zone Management Project (ICZMP) to improve national capacity for the implementation of comprehensive coastal management in India.
- Government also separated Structural(includes construction) and non-structural measures for effective disaster management of cyclones
- Solutions:
- The government should consider the NDMA Guidelines for the management of cyclones:
- Ensemble Warning System(EWS): Establish EWS involving observations, predictions, warnings, and customized local level advice for decision-makers (national, state, district level) to manage the impact of the cyclone (Read more about EWS)
- Commissioning of Aircraft Probing of Cyclone (APC): Guidelines calls for the combination of manned and Unmanned Aerial Vehicles (UAV) for critical observational data gaps.
- Cyclone Disaster Management Information System (CDMIS): Establishing a comprehensive department for coverage of all management information and provide online services to the departments of Disaster management.
- Specifying the roles and responsibilities in institutionalizing Cyclone risk mitigation with Developmental planning.
- Community Based Disaster Management (CBDM): Guidelines asked to launch such activities in all villages of the 84 districts vulnerable to cyclones.
Way forward:
- With the adverse Climate Change risks posted by IPCC reports the only option for India is to better preparedness for the disaster with better urban planning, community awareness, etc.
Typhoon Goni: Asia’s most powerful tropical storm of 2020?
News: Typhoon Goni has made landfall in the eastern Philippines.
Facts:
- Typhoon Goni: It is a tropical cyclone that recently made landfall as an extremely powerful Category 5–equivalent super typhoon in the Philippines.
Additional Facts:
- Tropical Cyclone: They are violent storms that originate over oceans in tropical areas and move over to the coastal areas bringing about large-scale destruction caused by violent winds, very heavy rainfall, and storm surges.
- Wind Direction: The winds blow counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere.
- Different Names: Tropical Cyclones are known by different names in different regions:
- Cyclones in the Indian Ocean
- Hurricanes in Atlantic
- Typhoons in the Western Pacific in the South China Sea
- Willy-Willies in Western Australia.
- Conditions: The conditions favorable for the formation and intensification of tropical cyclones are:
- Large sea surface with a temperature higher than 27° C;
- Presence of the Coriolis force;
- Small variations in the vertical wind speed;
- A pre-existing weak- low-pressure area or low-level-cyclonic circulation and
- Upper divergence above the sea level system.
Super Cyclone Amphan Is Set to Hit India and Bangladesh
Source: Click here
News: Cyclone Amphan has intensified into a super cyclonic storm and is expected to make landfall between West Bengal and Bangladesh close to Sundarbans.
Facts:
Cyclone Amphan:
- Cyclone Amphan is a tropical cyclone formed over Bay of Bengal that has turned into a super cyclonic storm.
- The Cyclone Amphan is also the strongest storm to have formed in the Bay of Bengal since the super cyclone of 1999 that ravaged Paradip in Odisha.
Why does the Bay of Bengal receive higher Cyclones compared to Arabian Sea?
- Higher Rainfall: Bay of Bengal receives higher rainfall which provides required humidity for cyclone formation.
- Location: The typhoons originating in the Pacific Ocean too influence the cyclones in BOB not the case in Arabian Sea.
- Constant Inflow of Fresh Water: The inflow from the Ganga and Brahmaputra rivers makes it impossible for the warm water to mix with the cooler water making it ideal for a cyclonic depression.
- Sluggish Winds: It keeps temperatures relatively high of about 28 degrees around the year.
Reasons responsible for intensification of Cyclones in Bay of Bengal:
- In 2020, the Bay of Bengal has observed record summer temperatures due to global warming from fossil fuel emissions that have been heating up oceans.
- However, such unusual warming around India is no longer restricted to just the BoB but also the Arabian Sea and the Indian Ocean.It makes storm prediction less reliable as well as disrupting monsoon patterns.
- Further, reduced particulate matter emissions during the lockdown resulted in fewer aerosols such as black carbon that are known to reflect sunlight and heat away from the surface.
Classification of Cyclones: The criteria followed by Indian meteorological Department(IMD) to classify Cyclones in the Bay of Bengal and in the Arabian Sea are as under:
Types of Disturbances | Associated Wind Speed in the Circulation |
Low Pressure Area | <31 km/hr |
Depression | 31-49 km/hr |
Deep Depression | 50-61 km/hr |
Cyclonic Storm | 62-88 km/hr (Here,IMD assigns the name to Cyclone) |
Severe Cyclonic Storm | 89-118 km/hr |
Very Severe Cyclonic Storm | 119-221 km/hr |
Super Cyclonic Storm | >222 km/hr |
Different Colour Codes:
- Green(No warning): No advisory is issued in such cases.
- Yellow(Be updated): It indicates severely bad weather panning across several days.It also suggests that the weather could change for the worse causing disruption in day-to-day activities.
- Orange/ Amber(Be prepared): It is issued as a warning of extremely bad weather with the potential of disruption.It is also a sign for people to prepare for evacuation and protect themselves from bad weather.
- Red(Take action): It is issued when the extremely bad weather conditions are certainly going to disrupt life.In this case, people must take all measures to protect their families and follow the instructions of local authorities and disaster-response teams.
Additional Facts:
- IMD:It was established in 1875 under the Ministry of Earth Sciences.It is the principal agency responsible for meteorological observations, weather forecasting and seismology.
Cyclones Titli
Context:The Regional Integrated Multi-Hazard Early Warning System (RIMES) has termed ‘Titli’, the severe cyclonic storm that devastated Odisha in October, as ‘rarest cyclone’.
Note: In October 2018, Severe Cyclonic Storm Gaza had hit coastal areas of Tamil Nadu
RIMES
- The RIMES is an intergovernmental body registered under United Nations.
- It is owned and managed by 45 collaborating countries in Asia Pacific and Africa Region.
- It seeks to establish regional early warning system within multi-hazard framework for generation and communication of early warning information and capacity building for preparedness and response to trans-boundary hazards.
- It provides information related to Tsunami and extreme weather conditions. It also acts as a test bed for emerging technologies and help to enhance performance
Cyclones in India:
Cyclones mainly occur during post monsoon and less in pre-monsoon and monsoon season. Cyclones affect both the Bay of Bengal and the Arabian Sea; however, the Bay of Bengal witness more cyclones than the Arabian Sea. This is because:
- Bay of Bengal has higher ocean surface temperature than the Arabian Sea. This helps in formation and intensification of cyclonic storms
- High rainfall and inflow of freshwater:
- The Bay receives higher rainfall and a constant inflow of freshwater. Therefore, its surface water keeps getting refreshed, making it impossible for the warm water to mix with the cooler water below, making it ideal for depression.
- On the other hand, enhanced vertical mixing in the Arabian Sea limits cyclone intensification.
- Role of remnants:
- Cyclones that form over the Bay of Bengal are either those develop insitu over southeast Bay of Bengal and adjoining Andaman Sea or remnants of typhoons over Northwest Pacific and move across south China sea to Indian Seas. As the frequency of typhoons over Northwest Pacific is quite high, the Bay of Bengal also gets higher number of cyclones.
- On the other hand, the cyclones over the Arabian Sea either originate insitu over southeast Arabian Sea or remnants of cyclones from the Bay of Bengal that move across south peninsula. As the majority of Cyclones over the Bay of Bengal weaken over land after landfall, the frequency of migration into Arabian Sea is low.
What makes Cyclone Titli unique?
Cyclone Titli
Both India Meteorological Department and the RIMES designated as “rarest cyclone” because of its following unique characteristics:
- North-eastward recurvature (change in direction) over the land: The normal behaviour of the cyclones forming in the Indian seas is that after deriving strength from the moisture in waters such as the Bay of Bengal, they move west, incline in a northerly direction and move out into the sea or land, depending on their origin. However, cyclone Titli recurved in a north-easterly direction over the land. It had made a recurvature away from coastal areas for more than 2 days
- Retaining its destructive potential after landfall: After landfall, a cyclone loses speed and intensity as it loses the source of energy from warm ocean waters and gradually dissipates. However, cyclone Titli, recurved its path and gained intensity.
Note: Recurving occurs due to air currents in the local atmosphere that push cold air from the poles towards the equator and interfere with cyclone formation.
How are Cyclones named?
- In the beginning, storms were named arbitrarily.
- The tradition of naming cyclones started with hurricanes in the Atlantic Ocean, where tropical storms that reach sustained wind speeds of 39 miles per hour were given names
- In 1953, the US weather service officially adopted the idea and created a new phonetic alphabet (international) of women’s names from A to W, leaving out Q, U, X, Y and Z.
- Male names were included in 1978.
- The process of naming cyclones involves several countries in the region and is done under the aegis of the World Meteorological Organization.
- For the Indian Ocean region, deliberations for naming cyclones began in 2000. A formula was adopted in 2004
How has naming a cyclone helped?
- It helps in the quick identification of storms in warning messages
- Names are presumed to be far easier to remember than numbers and technical terms.
- Giving names to storms makes it easier for the media to report on tropical cyclones, heightens interest in warnings and increases community preparedness
Impact of Cyclone Titli:
The Odisha government, with support from the World Bank National Cyclone Risk Mitigation project, increased disaster preparations including building shelters, evacuation planning, conducting drills and strengthening embankments. It had initiated Mission zero causality for all disasters. However, its Cyclone risk management has been primarily focussed on coastal areas. The unique nature of Titli-its recurvature and retention of intensity even after landfall had posed serious challenge and led to death and destruction in non-coastal areas.
Disaster Management of Cyclone in India
- Pre-Disaster
Structural Measures:
Structural measures include construction of cyclone shelters, construction of cyclone resistant buildings, road links, culverts, bridges, canals, drains, saline embankments, surface water tanks, communication and power transmission networks etc.
Non-Structural Measures:
Non-structural measures include early warning dissemination systems, management of coastal zones, awareness generation and disaster risk management and capacity building of all the stakeholders involved.
- During Disaster: Immediate rescue operations, supply of water, medicines, food and other necessary items, Damage assessments
- Post Disaster: Rehabilitation, Providing financial assistances, arrangements of relief measures.
Government Initiatives
National Cyclone Risk Mitigation Project (NCRMP)
Aim: The scheme aims to:
- upgrade cyclone forecasting, tracking and warning systems,
- build capacity in multi-hazard risk management
- Construct major infrastructures including multi-purpose cyclone shelters and embankments.
Principal Components: The major components under the scheme are:
- Community mobilisation and training
- Cyclone Risk Mitigation Infrastructure (construction of cyclone shelters, roads/missing links and construction/repair of Saline Embankments etc.)
- Technical assistance for capacity building on Disaster Risk Management (risk assessment, damage and need assessment)
- Capacity Building and knowledge creation along with project management and implementation support
Integrated Coastal Zone Management Project (ICZMP)
- It is a World Bank assisted project which aims at national capacity development for implementation of comprehensive coastal management in India. Broad objectives of the project include:
- Cyclone forecasting
- Tracking and warning systems
- Cyclone Risk Mitigation and Capacity Building
- Major infrastructure to be constructed under multipurpose cyclone shelters, access roads, underground cabling and saline embankments
- Disaster Mitigation
- Lowering loss of lives, property in vulnerable states
NDMA Guidelines:
- Establishment of exclusive eco-system monitoring network to study the impact of climate change
- Adoption of Aircraft Probing of Cyclone (APC) facility to fill the critical observational data gaps and significantly reduce the margin of error in predicting cyclone track, intensity and landfall
- Establishment of a comprehensive Cyclone Disaster Management Information System (CDMIS)
- Establishment of a state-of-the-art cyclone early warning system (EWS) involving observations, predictions, warnings and user friendly advisories
- Structural mitigation should be taken up which include- improvement in structural lifeline infrastructure, construction of multi-purpose cyclone shelters and cattle mounds, ensuring cyclone resistant design standards in rural and urban housing schemes, building all-weather road links, bridges, culverts and saline embankment
- Management of coastal zones should include mapping and delineation of coastal wetlands, patches of mangroves and shelterbelts and identification of potential zones for expanding bio-shield spread based on remote sensing tools.
Way Ahead
- The Early Warning System for cyclones should be strengthened to ensure timely and accurate information about cyclone- its track, intensity, time of landfall and likely impacts.
- A rare cyclone like Titli highlighted the lack of impact-based actionable early warning information and prior experience in addressing such disasters. Therefore, research and detailed assessment is necessary combat such disasters in future.
- It is important to ensure timely dissemination of warning. IMD’s cyclone alerts should be disseminated by broadcasters to all levels of governance and public
- The disaster management authorities should be more proactive in search and rescue operation after a cyclone disaster so that the loss of life can be negated.
- There should be proper coordination between the Centre, State and several Government agencies, and trained personnel for prompt and organised response after a cyclone.
- Structural measures such as designing and building of robust cyclone proof shelters, ensuring availability of essential infrastructure is important.
- Rapid urbanization and increasing encroachment in coastal areas is a major problem. Coastal Regulation zone norms should be strictly enforced.
- Awareness generation among all stakeholders is important for cyclone risk mitigation.
- Odisha State Disaster Management Authority should learn lessons from Cyclone Titli to evolve measures to minimise impacts in both coastal and non-coastal regions more effectively in future
Explained: Why cyclones hit the east coast in October, and how they are predicted
Explained: Why cyclones hit the east coast in October, and how they are predicted
News:
- The article talks about the hurdles the scientists face in accurately predicting the cyclones along with conditions in Bay of Bengal.
Important Facts:
2. Recently cyclone Titli became the third major cyclone to hit the Odisha-Andhra coastal zone in the last five years, all in October.
3. Cyclone Titli struck in same month as Phailin and Hudhud, but still the forecasting department failed to notice its arrival.
4. Reasons for poor forecasting:
- Poor data gathering technique: India have to rely on satellite images that reveals little data on moisture content and intensity to predict the developing cyclones over Indian ocean were as US has dedicated aircraft in the Atlantic basin, which fly directly into the clouds to study moisture levels and gather various data on cyclone profile.
Indian scientists get a more detailed picture only when a cyclone is 300-400 km from the coast, which reduces preparation time.
- Lack of budgetary support: India acquires storm prediction models from the US and Europe but lacks the resources to upgrade the models regularly.
- Cyclone Titli was additionally hard to read because it turned into a recurving cyclone (it changed direction.
- Season and frequency of cyclones in Bay of Bengal:
- The Bay of Bengal receives the remnants of major landfalls in the Philippines, China and South Asia.
- From these places come low-pressure systems that develop into a monsoon depression or a cyclone in Bay of Bengal.
- This is because it is adjacent to the northwest Pacific, which is one of the world’s most active basins for typhoons.
- The cyclones such as Titli, Phailin (2013) and Hudhud (2014) typically strike in October because of wind shear.
- Low wind shear, when combined with surface sea temperatures greater than 26°C, raises the likelihood of cyclones.
- Evacuation during cyclones:
- Researchers classify evacuation exercises as preventive, vertical, and shelter-in-place.
- Preventive (or horizontal) evacuation: The impact area is completely evacuated, but this is a measure rarely taken in India because of poor roads and inadequate public transportation. Also, poor people rarely have the resources to find alternative accommodation.
- Vertical evacuation: Here people are directed to specially designed buildings within the impact area. This strategy was largely followed during Cyclone Titli.
- Shelter-in-place evacuation: It involves fortification of existing houses and community buildings, which require financial resources.
- Storm surge and saving lives:
- During Titli, Hudhud or Phailin, lives were saved because, unlike the 1999 Super Cyclone, there was no storm surge.
General
Link between Dam and Natural disasters – Explained Pointwise
Table of contents:
Rishiganga dam in Uttarakhand was recently destroyed by the Glacial Lake Outburst Flood and intensified the GLOF in the region. This is not the first time a Dam is aiding and intensifying the disaster in India. It can be a potential hazard to both human life and the environment. This raises a larger question on the net benefit of big dams.
What is Dam?
It is a structure built across a stream or river to hold back water. There are many reasons to build a dam. Such as,
How dams are aiding disasters?
Dams were built to provide benefits to human. But many times instead of providing benefits, dams are harming the region by aiding a disaster. The reasons are:
- Dams as a hydropower plant: Construction of hydro-power plant requires diversion of rivers through tunnels to generate power. The construction of these tunnels unsettles the mountainous terrain by displacing the supportive sediment. It results in the slipping down of rocks due to the removal of their support system (Landslides).
- Dams as a reason for frequent floods: Due to poor maintenance, siltation, etc. dams are not able to hold adequate water. This is responsible for the increasing frequency of floods in India.
- Dam as a solution to prevent/divert large run-off water: To protect the river run-off, many bigger dams have been constructed in highly vulnerable locations, like the Himalayas. For example, the entire state of Uttarakhand is vulnerable to earthquakes, but there are large dams planned in the fragile region that disturb the ecosystem. Dams in these locations aggravate the natural disaster.
- Dams as a reason for an earthquake: When a large quantity of water is loaded and unloaded frequently in the region, it might lead to reservoir induced seismicity. For example, Koyna earthquake of December 1967.
All these reasons lead to dam failure. This is then followed by a large-scale release of water, downstream of the river and creating floods. This will create economical, infrastructural, environmental, and livelihood losses.
Dams aided disasters in the past:
- The worst dam disaster in India was the Machu dam failure (Gujarat) in 1979. The torrential rainfall in the area created a large scale flood and a failure in the dam. According to the official estimates, around 2000 people had lost their lives.
- In August 2018 Kerala witnessed its worst floods since 1924 due to the torrential rainfall. Too much water stored in the dam aggravated the disaster. At least 35 of 50 large dams had been opened for releasing water in to the already flooded areas. The flood took the lives of around 503 people in the state.
- Similarly, in 2019 heavy rain caused a breach in Tiware dam (Maharastra). This led to the flooding of seven villages and 20 people swept away.
- Most recently, a Glacial Lake Outburst Flood destroyed the Rishiganga dam. This led to a large surge of water downstream which breached the Tapovan Hydropower Plant.
Vulnerability of Indian dams:
- India has more old dams. India in total has 5,745 reservoirs in the country, of which, 293 are more than 100 years old. The age of 25% of the dams is between 50 and 100 years and the remaining 80% are over 25 years old. Ageing dams face the following issues,
- Differential settlement of foundation in the dam,
- Clogging of filters, increase of uplift pressures,
- Cracks in the dam core,
- Loss of bond between the concrete structure and embankment,
- Reduction in slope stability in earthen and rockfill dams,
- Erosion of earthen slopes,
- Deformation of the dam body itself.
All these aids the intensification of any disaster.
- Many dams have structural deficiencies and shortcomings in operation and monitoring facilities. Few dams not even meet the present safety standards on structural and hydrological conditions.
- Many states are not providing sufficient budgets for the maintenance and repair of the dam. There is also a lack of institutional and technical capacities for addressing dam safety issues. For example, According to Central Water Commission data, “Not even a single dam in Kerala was inspected before monsoon during Kerala floods”.
- The current legal framework does not have any provision for penalizing the person/trust/state responsible for dam failure.
- Real-time inflow forecasting systems are not in place even in important reservoirs. This creates vulnerability to dam safety and dam operation.
Government Initiatives to improve dam safety:
- Dam Rehabilitation and Improvement Project (DRIP)
- It is a World Bank assisted project. The project aims to improve the safety and operational performance of selected existing dams and associated appurtenances sustainably.
- Ministry of Water Resources, River Development & Ganga Rejuvenation through the Central Water Commission, is implementing the project.
- Dam Safety Bill, 2019.
- The Bill provides for proper surveillance, operation, inspection, and maintenance of all specified dams in the country.
- The Bill aims to constitute the National Committee on Dam Safety. The committee shall suggest dam safety policies and also recommend any necessary regulations.
- The Bill also establishes the National Dam Safety Authority. The NDSA is a regulatory body that discharges functions to implement the policy, guidelines, and standards in the country.
- The Bill also provides for the constitution of a State-level Committee on Dam Safety by State Governments.
- Dam Health And Rehabilitation Monitoring Application (DHARMA)
- It is a web-based software package. It supports the effective collection and management of Dam Safety data in all large dams of India.
- The major aim of DHARMA is to digitize all dam related data.
- Seismic Hazard Assessment Information System (SHAISYS) for mapping Seismic Hazards.
Suggestions to make dams disaster-resilient:
- State governments should strictly follow the dam safety manual.
- Creation of the buffer zone: States have to ensure that there is no encroachment in the nearby area.
- Need to integrate urban-rural planning with dam safety. Since India is a populous country, it is impossible to shift people during calamities. Proper dissemination of information on a real-time basis and regular flushing of water has to be carried out downstream to keep the river beds dry. This can be done only through an integrated approach.
- A Standing Committee recommended a penal provision for dam failures on authorities. The government has to incorporate this into law. Along with that, the government has to increase the capacity building of locals and associated institutions.
- The government has to create a well-planned monitoring system using modern instruments. This is the key to the early detection of defects and averts disasters.
The government must consider the issue holistically and avoid building large dams for political gains in fragile regions. The construction of a dam is not a disaster, but the mismanagement and poor planning of the dam is a disaster which affects all of us in a severe manner. It is a high time for the government to understand this.
Reasons and Solutions for disaster management in Uttarakhand
Synopsis: There are various reasons for Disasters in Uttarakhand. It can be prevented by taking some long-term measures.
Background:
- The glacier burst in the Chamoli district of Uttarakhand caused the flash floods. It led to the death of 34 people with more than 170 people missing.
- Apart from that, it also caused destruction to public and private infrastructure. For example, It damaged the NTPC’s Tapovan-Vishnugad hydropower project and the Rishiganga mini-hydro project.
- The recent disaster reminds the 2013 disaster in Uttarakhand which resulted in the death of thousands of people.
- The scientific community still doesn’t have the exact reason for the cause of this disaster.
What are the possible reasons for the cause of the disaster in Uttarakhand?
The scientific community still doesn’t have the exact reason for this disaster. However, some possible reasons are discussed below.
- First, the Natural ecology of Uttarakhand and its fragile mountain ecosystem is prone to such disaster. Uttarakhand is located between the young and unstable mountains. Moreover, intense rainfall makes it more vulnerable.
- Second, as per geologists, glaciologists, and climate experts, climate change, rapid and indiscriminate construction activities, and the subsequent ecological destruction are disturbing the balance of the ecosystem in this region.
- For example, The Hindu Kush Himalaya Assessment Report (2019) had pointed out that one-third of the Hindu Kush Himalaya’s glaciers would melt by 2100. It may happen even if all the countries in the region fulfilled their commitments under the Paris Agreement.
- It also warned that any ecologically destructive activities would lead to more intensified disasters like landslides.
- Third, according to the Wadia Institute of Himalayan Geology, rock mass might have weakened due to intense freezing and thawing of snow. This may have created a weak zone. Fractures led to a collapse that resulted in flash floods.
- Fourth, Experts also opine that massive deforestation is a possible reason for the disaster. For example, in 2014, the Chopra committee established that the haphazard construction of dams can cause irreversible damage to the region.
- Fifth, there are also possibilities that the use of explosives in the construction of dams and other infrastructure would have weakened the rock strata.
What needs to be done?
- First, Government should Invest in long-term crisis response mechanisms and resilience solutions such as,
- Flood prevention and rapid response.
- Road stabilization technologies for fragile road networks, bridges, culverts, and tunnels.
- Strengthening embankments using scientific knowledge.
- Investing in monitoring and early warning system.
- Investing in training and capacity building of local communities to prevent and manage risks effectively.
- Second, hydropower and other public infrastructure projects need reassessment based on the sensitivity of local ecology.
- Third, implementing pragmatic policies and regulatory guidelines such as responsible eco- and religious tourism policies. This will restrict detrimental human activities.
- Fourth, applying innovative and inclusive solutions that support nature and marginalized communities, to restore and rebuild a resilient future for Uttarakhand.
Mindless development could bring more calamities
Synopsis: Development work in the Himalayas is being carried out without an understanding of its fragility, seismicity, glacial behavior.
Introduction
The flash floods due to the burst of an artificial lake inside Nanda Devi Sanctuary is the newest warning given by the Himalayas to the supporters of development. The loss of lives, property, and projects is estimated at more than Rs. 4,000 crore.
- According to Planet Labs, ice along with frozen mud and rocks fell down from a high mountain inside the Nanda Devi Sanctuary.
- The current winter season has had less rain and snow as a result the effects of chemical weathering were much more active in the higher Himalayas.
- Rishi Ganga has seen similar devastations in the past. There was a lake burst in Rishi Ganga in 1968. Another lake burst in Rishi Ganga was seen at the time of the 1970 Alaknanda floods.
How have the developmental activities caused troubles in the Himalayan region?
Development activities have increased the destructive powers of the calamities as less destructive methods, technologies and rules are available but not followed.
- Firstly, studies have suggested that the pace of climate change is faster in mountains and fastest in the Himalayas. The huge displacement of soil, silt, and stones in the river floor owing to development projects force the raging river to behave differently.
- Secondly, the projects have been carried out despite the protests by the local people.
- People protested against the Vishnu Ganga project, which was devastated in the 2013 floods and rebuilt.
- The people of Reni protested against the Rishi Ganga project as they were aware of the river’s flood history. The Supreme Court and the Uttarakhand High Court gave judgments against the construction of dams in the inner Himalayas.
- Thirdly, a slight error in the monsoon forecast alters the preparedness in the region resulting in a severe calamity.
- In the 2013 calamity, the India Meteorological Department wrongly announced that the monsoon will reach Uttarakhand by June 27-28. It reached a week before with 300-400 percent more rain. Thus, the death toll and scale of destruction was record-breaking.
- Fourthly, any hindrance in the river-bed increases the power of the river. In such a situation, water and silt dominate the surrounding and downstream areas. For example, the VishnuPrayag Project was destroyed by the combined power of Khiron Gad and Pushpawati.
- Fifth, the assessment of committees is not implemented. The Ravi Chopra committee formed by the SC recommended the closure of all the 24 hydro projects by the Wildlife Institute of India.
- Moreover, Environmental Impact Assessment (EIA) was a function of independent functionaries. Now this task is assigned to a government agency.
Way forward
Locals do not want to risk their homes, fields, etc. in the name of development. The Himalayas have been giving us life through water, fertile soil, biodiversity, wilderness, and a feel of spirituality. We cannot and should not try to control or dictate the Himalayas.
Fragility of Himalayan Mountain Ecosystem
Source: Down to Earth , The Hindu
Gs3: Conservation, Environmental Pollution, and Degradation, Environmental Impact Assessment.
Synopsis: The recent Glacial outburst in Uttarakhand’s Chamoli district is a consequence of human’s impact on climate and lack of awareness towards local ecology.
Background
- Recently a glacier collapsed in Uttarakhand’s Nanda Devi. According to some satellite images, the glacier collapsed as a result of a landslide. It resulted in flash floods in the Rishiganga and Dhauliganga rivers.
- It claimed many lives of persons working in two hydropower projects.
- Although the ITBP through immediate action rescued nearly 15 people still many people are found missing.
How Climate change is impacting the Mountain ecosystem and how it is impacting Human livelihood?
- Anthropogenic activities are continuously affecting the earth’s climate. The change in the Mountain ecosystem is an indicator of that effect.
- Mountain ecosystems are highly vulnerable to climate change owing to their altitude, slope, and orientation to the sun.
- Due to increased global warming, mountains glaciers are melting at unprecedented rates. It is reducing the area for the survival of flora and fauna.
- For example, satellite observations reveal that across India, China, Nepal, and Bhutan the melting of glaciers has doubled since the start of the 21st century.
- The melting of glaciers threatens water sustainability for hundreds of millions of people in counties, including India. These impacts become severe due to the increase in pressure on water resources for irrigation and food production, industrialization, and urbanization.
What are the reasons for climatic disaster in Uttarakhand?
The frequent disasters in Uttarakhand are not only caused by nature but also due to an indiscriminate increase in hydropower projects.
- Uttarakhand mountain ecosystem faces various threats such as seismicity, dam-induced micro seismicity, landslides. For example, the entire State of Uttarakhand falls under Zone-IV and V of the earthquake risk map of India.
- Besides being an earthquake-prone zone, it is also prone to Flood disasters. Bursting of glacial lakes can cause flash floods with catastrophic consequences. For instance, moderate earthquakes in the Tehri dam caused the 2013 floods in Kedarnath.
- Despite all these threats, the Uttarakhand government has indiscriminately pursued a greater number of hydropower projects. For example, the ongoing Tapovan power project.
- Also, India has heavily invested in dam development and the growth of hydropower in the Himalayas’ region to cut carbon emissions.
- For example, if the national plan to construct dams in 28 river valleys in the hills is completed, the Indian Himalayas will have one dam for every 32 km. (The highest density in the world).
- Apart from this, the life of dams is often exaggerated without taking a proper account of the siltation level in the dams. For example, in the Bhakra dam in Himachal Pradesh, the siltation was higher by 140% than calculated.
These hydropower projects are incompatible with the local environment and ecology. They have increased the risk of disaster manifolds impacting the life and livelihood of millions of people.
What is the way forward?
- The government should realize that the fragility of the Himalayan mountain’s ecosystems. Governments need to re-prioritize their projects based on the potential of the mountains, local and traditional knowledge as well as the aspirations of the place.
- Hydro projects should be confined to the areas with the least impact in the Himalayas. Also, the government needs to build more low-impact run-of-the-river power projects rather than building destructive large dams and reservoirs.
- Projects that are incompatible with the local environment and ecology should not be promoted just by giving due consideration to development or economic growth.
“Global Climate Risk Index 2021” – India is 7th Worst Hit Nation
What is the News?
German watch, the Germany-based think tank, released the Global Climate Risk Index,2021.
About the Index
- Data Sources: The index is prepared based on the data from the Munich Re NatCatSERVICE11. The data is identified as one of the most reliable and complete databases worldwide, on this matter. Other than that, It also uses Socio-Economic data from the International Monetary Fund (IMF).
- Functions: It analyses quantified impacts of extreme weather events. This analysis is presented both in terms of fatalities and economic losses, due to extreme weather events.
Key Findings of the report for India:
- India ranked at 7th Position in Climate Risk Index 2021. It means India is the 7th worst-hit country by extreme weathers. In 2020, India ranked 5th on the index.
- Monsoon in India: In 2019, the monsoon continued for a month longer than normal in India. 110% of the long-period average was recorded, between June to September 2019.
- Flooding caused by heavy rain was responsible for 1,800 deaths across 14 states. It led to the displacement of 1.8 million people.
- Cyclones: There were 8 tropical cyclones in India. 6 of them intensified to become “very severe”. ‘Extremely Severe’ Cyclone Fani affected 28 million people killing 90 people in India and Bangladesh causing economic loss to the tune of US$8.1 billion.
Other Key Findings:
- As per the report by German Watch, there were 11,000 extreme weather events globally between 2000 and 2019. Due to these events, over 4,75,000 people lost their lives and economic losses were around the US $2.56 trillion (in purchasing power parities).
- Top 3 countries: Mozambique, Zimbabwe, and the Bahamas were respectively the top three countries, most affected in 2019.
- Top 3 Countries most affected in the past 20 years: Between 2000-2019, Puerto Rico, Myanmar and Haiti were the countries most affected by the impacts of such weather events.
Source: TOI
Global Risk Report, 2021
Why in News?
The World Economic Forum(WEF) has released the 16th edition of the Global Risk Report, 2021.
Report findings are based on the Global Risks Perception Survey (GRPS). GRPS was undertaken by more than 650 members of leadership communities of WEF (World Economic Forum).
Aim: To highlight the risks and consequences of widening inequalities and increasing societal fragmentation, due to the COVID-19 pandemic, in 2021 and over the next decade.
Key Takeaways:
- Top Risk by Impact: The risk posed by infectious diseases has been ranked as no. 1 on the list of risks, while in 2020 was listed at 10th place.
- Impact of Covid-19: The immediate human and economic cost of COVID-19 is huge. It threatens to scale back years of progress on reducing global poverty and inequality. It will also damage social cohesion and global cooperation.
- Climate concerns: Despite the impact of COVID-19, climate-related matters make up the bulk of this year’s risk list. The report has described these threats as an existential threat to humanity.
- Widening digital gaps: Digitalization which was accelerated by the pandemic is widening the digital gap between individuals and across countries. Thereby it is aggravating existing inequalities, polarization, and regulatory uncertainties.
- Intensifying pressures on businesses: Businesses under increasing pressures from inward-looking national agendas, greater market concentration, and popular scrutiny and volatility.
Recommendations: According to the report, response to COVID-19 offers four governance opportunities to strengthen the overall resilience of countries, businesses, and the international community:
- Formulating analytical frameworks that take a holistic and systems-based view of risk impacts.
- Investing in high-profile risk champions to encourage national leadership and international cooperation.
- Improving risk communications and combating misinformation.
- Exploring new forms of public-private partnership on risk preparedness.
India bore maximum brunt of extreme weather events in 2020: Report
Source: The New Indian Express
News: An International Report titled “Counting the cost 2020: A year of climate breakdown” has been released by Christian aid, a relief and humanitarian agency based in London.
Facts:
- The report listed 15 most destructive climate disasters of 2020 that cumulatively had an expenditure tag of around $150 billion calculated only on insured losses.
Key Takeaways from the report:
Source: New Indian Express
- Cyclone Amphan which affected countries in the Bay of Bengal and caused maximum damage within coastal districts of West Bengal of India displaced 4.9 million people accounting for the biggest displacement due to an extreme weather event anywhere in the world in 2020.
- Economic Impact: The economic impact of the Cyclone Amphan was fourth in global climate related disaster list following the United States and Caribbean hurricanes, China floods and the United States fires on the west coast.
- Floods in India: The floods in India were the fifth most expensive extreme weather event in the world costing the country $10 billion.
- More importantly, as many as 2,067 lives were lost during the June-October floods, the highest number of fatalities due to climate change-induced weather events this year.
In India, over 75% districts hotspots of extreme weather events, finds study
News: Council on Energy, Environment and Water (CEEW) has released a report titled “Preparing India for Extreme Climate Events”.This is the first time that extreme weather event hotspots in the country have been mapped.
Key Takeaways:
- Hotspots: Over 75% of districts in India are hotspots of extreme climate events such as cyclones, floods, droughts, heat waves and cold waves.
- Extreme Climate Events: The frequency, intensity, and unpredictability of extreme events have risen in recent decades.While India witnessed 250 extreme climate events in 35 years between 1970 and 2005, it recorded 310 such weather events in only 15 years since then.
- Cyclones: After 2005, the yearly average number of districts affected by cyclones tripled and the cyclone frequency-doubled.
- Floods: The decade 2000-2009 showed a spike in extreme flood events and in associated flood events which affected almost 473 districts.
- Droughts: The yearly average of drought-affected districts increased 13 times after 2005.Until 2005, the number of districts affected by drought was six, but after 2005 this figure rose to 79.
- Microclimatic zones shifting: These are areas where the weather is different from surrounding areas.The study has found that they are shifting across various districts of India.
- Reasons: Some reasons behind this shift in microclimatic zones is change in land-use patterns, disappearing wetlands and natural ecosystems by encroachment and urban heat islands that trap heat locally.
Recommendations:
- Develop a Climate Risk Atlas to map critical vulnerabilities such as coasts, urban heat stress, water stress, and biodiversity collapse
- Develop an Integrated Emergency Surveillance System to facilitate a systematic and sustained response to emergencies
- Mainstream risk assessment at all levels, including localised, regional, sectoral, cross-sectoral, macro and micro-climatic level
- Enhance adaptive and resilience capacity to climate-proof lives, livelihoods and investments
- Increase the participatory engagement of all stakeholders in the risk assessment process
- Integrate risk assessment into local, sub-national, and national level plans.
Hazardous ideas for Himalayas
Context: China’s major hydropower project as a part of its 14th Five-Year Plan (2021-25), on the Yarlung Zangbo River, in Mêdog County in Tibet.
More on news:
- The hydropower generation station is expected to provide 300 billion kWh of electricity annually. The Chinese authorities say the project will help the country realise its goal of reaching a carbon emission peak before 2030 and carbon neutrality before 2060.
- Indian counterparts were quick to restate their plans to dam the Himalayas on this side of the border. India is reportedly considering a 10-GW hydropower project in an eastern State.
What are the various misadventures that can happen due to the building of hydropower dams?
- Unavailability of dams: Both countries ignore how unviable such ‘super’ dams projects are, given that they are being planned in an area that is geologically unstable.
- Competing dams: Over the past 20 years, both China and India have been competing with each other to build hydroelectric dams in this ecologically fragile and seismically vulnerable area.
- There are two hydropower projects in the works in Arunachal Pradesh on the tributaries of the Brahmaputra: the 600 MW Kameng project on the Bichom and Tenga Rivers and the 2,000 MW Subansiri Lower Hydroelectricity Project.
- China has already completed 11 out of 55 projects that are planned for the Tibetan region.
- Overestimating economic potential: In executing these hydroelectric projects, the two countries have overestimated their economic potential and grossly underestimated the earthquake vulnerability of the region.
- Earthquakes in the region: High seismic zones coincide with areas of high population concentration in the Himalayan region where landslides and glacial lake outburst floods are common.
- About 15% of the great earthquakes of the 20th century occurred in the Himalayan region. The northeast Himalayan bend has experienced several large earthquakes of magnitude 7 and above in the last 100 years, more than the share from other parts of the Himalayas.
- The 2015 Gorkha earthquake of magnitude 7.8 in central Nepal resulted in huge losses in the hydropower sector. Nepal lost about 20% of its hydropower capacity consequent to the earthquake.
- Landslides: The main mechanisms that contributed to the vulnerability of hydropower projects were found to be landslides, which depend on the intensity of seismic ground shaking and slope gradients.
- Heavy siltation from giant landslides expected in the project sites will severely reduce the water-holding capacity and life expectancy of such dams.
- Even without earthquakes, the steep slopes made of soft rocks are bound to slide due to deforestation and road-building.
What can be done?
- Nature reserve: In recent years, the Himalayas have seen the highest rate of deforestation and land use changes. The upper Himalayas should be converted into a nature reserve by an international agreement.
- Himalayan river commission: The possibility of a Himalayan River Commission involving all the headwater and downstream countries needs to be explored.
Way forward
- India and China, the major players in the region, would be well advised to disengage from military adventurism and seek ways of transforming this ‘roof of the world’ into a natural reserve for the sake of humanity. Carbon neutrality should not be at the expense of the environment.
Crucial expertise of CAPFs
Context: The diverse experience of security forces has helped greatly in combating COVID-19.
Discuss the role of CAPFs during the pandemic?
- Central Armed Police Forces (CAPFs) carry out the task of overcoming the disaster, by not only carrying out rescue and relief operations, but also by moderating the pains and problems arising out of the disaster.
- CAPFs comprise the Central Reserve Police Force (CRPF), Border Security Force, Central Industrial Security Force, Sashastra Seema Bal, Assam Rifles and the ITBP.
- Role played by the CAPFs:
- Setting up Quarantine centres: Even before covid-19, the Indo-Tibetan Border Police (ITBP) had already set up its 600-bed quarantine centre in Chawla on the outskirts of New Delhi.
- Quarantine assistance: Out of the 324 Indian passengers in the first batch that arrived in New Delhi from China’s Wuhan, 103 were quarantined at the ITBP Centre.
- Coordinated response: The Union Ministry of Health and Family Welfare had roped in specialists from the Safdarjung Hospital to coordinate with ITBP officials.
- Similarly, The Ministry of Home Affairs (MHA) had directed the CAPFs to establish 5,400-bedded quarantine centres with 75 isolation wards, spread over 37 centres across the country.
- Testing and Training: Immigration officials entrusted with conducting COVID-19 tests of the passengers arriving in New Delhi were trained by the NDRF.
- The NDRF has trained over 30,000 personnel in disaster management across the country.
- Role of Disaster Response Forces: The NDRF has been carrying out rescue and relief operations, and is also training the State Disaster Response Forces personnel in all States.
- Relief work: A sum of ₹10 crores was sanctioned for the CRPF by the MHA to carry out relief work for those displaced in the aftermath of the lockdown.
- Expertise and SOPs: The expertise acquired by ITBP personnel and the Standard Operating Procedure prepared by the ITBP came handy for the States and other police forces in establishing their own quarantine centres and COVID-19 hospitals.
- For instance, a 10,000-bed quarantine centre was established in Chhatarpur in New Delhi by the ITBP, where over 10,000 patients have been treated till now, according to ITBP spokesperson.
What steps can be taken?
- There is a need to expand the strength of trained personnel. Personnel can be deployed at quarantines centres after short term courses.
- A proposal mooted by NITI Aayog last year, to conduct a bridge course for dentists to solidify them eligible for the MBBS degree, could be revived, and such doctors could be on stand-by to help in such emergency crises.
It is these CAPF personnel who give an impression of existence of government administration even in the remotest corners of the country. Their versatile experience can be utilised to the nation’s advantage.
Other Water and Climate related disasters
Reasons and Solutions for disaster management in Uttarakhand
Synopsis: There are various reasons for Disasters in Uttarakhand. It can be prevented by taking some long-term measures.
Background:
- The glacier burst in the Chamoli district of Uttarakhand caused the flash floods. It led to the death of 34 people with more than 170 people missing.
- Apart from that, it also caused destruction to public and private infrastructure. For example, It damaged the NTPC’s Tapovan-Vishnugad hydropower project and the Rishiganga mini-hydro project.
- The recent disaster reminds the 2013 disaster in Uttarakhand which resulted in the death of thousands of people.
- The scientific community still doesn’t have the exact reason for the cause of this disaster.
What are the possible reasons for the cause of the disaster in Uttarakhand?
The scientific community still doesn’t have the exact reason for this disaster. However, some possible reasons are discussed below.
- First, the Natural ecology of Uttarakhand and its fragile mountain ecosystem is prone to such disaster. Uttarakhand is located between the young and unstable mountains. Moreover, intense rainfall makes it more vulnerable.
- Second, as per geologists, glaciologists, and climate experts, climate change, rapid and indiscriminate construction activities, and the subsequent ecological destruction are disturbing the balance of the ecosystem in this region.
- For example, The Hindu Kush Himalaya Assessment Report (2019) had pointed out that one-third of the Hindu Kush Himalaya’s glaciers would melt by 2100. It may happen even if all the countries in the region fulfilled their commitments under the Paris Agreement.
- It also warned that any ecologically destructive activities would lead to more intensified disasters like landslides.
- Third, according to the Wadia Institute of Himalayan Geology, rock mass might have weakened due to intense freezing and thawing of snow. This may have created a weak zone. Fractures led to a collapse that resulted in flash floods.
- Fourth, Experts also opine that massive deforestation is a possible reason for the disaster. For example, in 2014, the Chopra committee established that the haphazard construction of dams can cause irreversible damage to the region.
- Fifth, there are also possibilities that the use of explosives in the construction of dams and other infrastructure would have weakened the rock strata.
What needs to be done?
- First, Government should Invest in long-term crisis response mechanisms and resilience solutions such as,
- Flood prevention and rapid response.
- Road stabilization technologies for fragile road networks, bridges, culverts, and tunnels.
- Strengthening embankments using scientific knowledge.
- Investing in monitoring and early warning system.
- Investing in training and capacity building of local communities to prevent and manage risks effectively.
- Second, hydropower and other public infrastructure projects need reassessment based on the sensitivity of local ecology.
- Third, implementing pragmatic policies and regulatory guidelines such as responsible eco- and religious tourism policies. This will restrict detrimental human activities.
- Fourth, applying innovative and inclusive solutions that support nature and marginalized communities, to restore and rebuild a resilient future for Uttarakhand.
Tapovan Vishnugad Hydropower Project
What is the News?
The rescue operations are still undergoing in Uttarakhand from a Tapovam tunnel located at the Tapovan-Vishnugad hydro project.
Facts:
- Tapovan Vishnugad Hydropower Plant is a 520 MW run-of-river hydroelectric project(See image). It was constructed by National Thermal Power Corporation Limited(NTPC) on Dhauliganga River in Chamoli District of Uttarakhand.
- The power plant is located on the downstream on the Alaknanda River (one of the two headstreams of the Ganges).
- Damaged: It was severely damaged in February 2021 due to flash flood caused by Uttarakhand glacier burst.
Read more about Glacial Lake Outburst Flood (GLOF)
Source: The Hindu
Landslip likely triggered Flash Flood: experts
What is the News?
According to glaciologists and experts, the cause of flash floods in Uttarakhand Chamoli district was most probably a landslip(Landslide) and not a glacial lake burst.
Why are experts calling it a Landslide and not a glacial lake burst?
- The glacial lake outburst flood(GLOF) occurs when a natural lake, formed from a glacial ice melt and the glacial lake is breached. However, available satellite images do not show the presence of a glacial lake before the flooding event.
- Moreover, the Central Water Commission(CWC) monitors and prepares monthly reports on the state of glacial lakes and waterbodies measuring 10 hectares and above via satellite. Nothing out of the ordinary was observed by CWC.
Then, what might have caused the flooding?
- There was a hanging glacier and on top of the glacier was a huge rock mass.
- The rock mass became loosened due to freezing, thawing, and temperature variation. It came crashing down, creating pressure on the hanging part of the glacier. The fresh snowfall had also been added to the weight over the hanging glacier.
- This hanging glacier broke off due to gravitational pull, slid down with the entire rock mass. It slowed down near the base of the valley, where the Raunthi Gadhera stream flows.
- As the huge mass slowed a bit, then stopped, it blocked the water of the stream and the water quantum kept increasing. This damming up of the stream increased to such an extent that it breached the whole accumulated mass of water.
- Hence, this whole mass of water, boulders, and rock mass came crashing down with force towards the Rishi Ganga dam site. It caused massive damage to the under-construction Tapovan hydel project and caused floods.
Source: The Hindu
More Related post
https://blog.forumias.com/glacial-lake-outburst-flood-glof-in-uttarakhand-explained/
https://blog.forumias.com/glacial-lake-outburst-floods-glof/
https://blog.forumias.com/what-are-the-ndma-guidelines-for-glofs-related-disasters/
What are the “NDMA guidelines for GLOFs related disasters”
What is the News?
NDMA has issued guidelines to reduce disasters related to Glacial Lake Outburst Floods (GLOFs). Recently GLOF is suspected to have caused the flash floods in Uttarakhand’s Chamoli.
What are Glacial Lake Outburst Floods(GLOFs)?
- It refers to the flooding that occurs when the water dammed by a glacier or a moraine is released suddenly.
Click Here to Read Further on GLOFs
- According to National Disaster Management Authority (NDMA), Climate change is facilitating the glacial retreat in most parts of the Hindu Kush Himalayas. It is resulting in the formation of numerous new glacial lakes. Due to that, this area has become prone to GLOFs.
NDMA Guidelines for Reducing GLOFs:
The NDMA, headed by PM, had issued detailed guidelines on how to reduce and deal with disasters caused by GLOFs:
- Identify and Mapping Dangerous Lakes: Potentially dangerous lakes can be identified. This identification will be based on field observations, past events, geomorphologic and geotechnical characteristics, etc.
- Use of Technology: It has recommended the use of Synthetic-Aperture Radar imagery. It will automatically detect changes in water bodies, including new lake formations, during the monsoon months.
- Structural Measures: It recommends reducing the volume of water with various methods to manage lakes structurally. Methods are pumping or siphoning out water and making a tunnel through the moraine barrier or under an ice dam.
- Example: In 2014, a landslide occurred along Phuktal (tributary to Zanskar river) in Kargil district of Ladakh. It led to a potential flood situation. The NDMA created an Expert Task Force which along with the Army used explosives to channel water from the river. It used controlled blasting and manual excavation of debris for this purpose.
- Constructions and development in High prone areas should be prohibited. It is a very efficient means to reduce risks at no cost.
- Land Use Planning: Land use planning regulations need to be developed. In downstream areas, Infra. development should be monitored prior to, during, and after the construction.
- Trained Local Manpower: Apart from specialized forces such as NDRF, ITBP, and the Army, there is a need for trained local manpower. These teams will assist in planning and setting up emergency shelters, distributing relief packages, identifying missing people, and addressing the needs for food, healthcare, water supply, etc.
- Early Warning System: A robust early warning system in vulnerable zones should be put in place.
- Emergency medical response team: Quick Reaction Medical Teams, mobile field hospitals, Accident Relief Medical Vans, and heli-ambulances should be set up in areas inaccessible by roads.
- Psychological Counselling: The guidelines also call for psychological counseling of victims.
Source: Indian Express
Glacial Lake Outburst Flood (GLOF) in Uttarakhand -Explained
Recently a glacial burst has occurred in Nanda Devi glacier in Uttarakhand’s Chamoli district. 19 bodies have been recovered so far and over 150 persons went missing in the glacial outburst. Many geologists issued warnings that these types of climate-related disasters are going to increase. They all pointed out global warming as a major contributing factor to these disasters.
What happened in Uttarakhand?
A part of the Nanda Devi glacier broke off and flooded the Rishiganga river in Chamoli district of Uttarakhand. It led to massive flood in the region that damaged many villages in its path. The flood also wiped out two hydroelectric power projects on its way;
- The Rishiganga hydroelectric power project (13.2 MW)
- The Tapovan hydroelectric power project on the Dhauliganga river (a tributary of the Alakananda).
The scientists call the glacial burst an “extremely rare event”. Whether it was a glacial lake burst or an avalanche, is still unknown.
Wadia Institute of Himalayan Geology, Dehradun has sent two teams of scientists to the area. The team will study the possible cause and find out the exact reason behind the glacial burst.
What is a glacier? and what is glacier retreat?Glaciers are large masses of ice that flow slowly downhill like water flowing down as a river. A glacier grows (advance) whenever snow accumulates faster than it melts. Glacier retreats (shrinks) whenever the melting exceeds accumulation. Most of the world’s glaciers have been retreating since about 1850.
What is Glacial burst?
Retreating glaciers, usually result in the formation of lakes at their tips. These lakes are called proglacial lakes. These proglacial lakes are often bound by sediments, boulders, and moraines.
If the boundaries of these lakes are breached, then flooding will take place downstream of that glacial lake. This is called a Glacial Lake Outburst Flood or GLOF.
The occurrence of GLOF will release a significant amount of water retained in a glacial lake. A large amount of water rush down to nearby streams and rivers (like the recent glacial burst that flooded the Rishiganga river). This further gathers momentum by picking up sediments, rocks, and other materials on the way.
In conclusion, GLOF will result in large scale flooding downstream.
These GLOFs have three major characteristics. They are,
- There will be a sudden release of water and sometimes this might be cyclic in nature.
- GLOFs are generally rapid events. They can range from a few hours to days.
- GLOFs result in large downstream discharges in the river. (This often depend on the amount of glacial lake size, level of the breach in the boundary of the glacial lake, etc).
What are the possible reasons behind the Glacial burst?
Due to multiple reasons, there occurs breach of boundaries of the glacial lake. Like,
- A build-up of water pressure or structural weakness of the boundary due to an increase in the flow of water.
- An earthquake (Tectonic) or cryoseism (non-tectonic seismic event of the glacial cryosphere) can cause GLOF. During this, the boundary of the glacial lake will collapse suddenly and release the water of the glacial lake.
- An avalanche of rock or heavy snow: During this, the water in the glacial lake might be displaced by the avalanche.
- Volcanic eruptions under the ice can lead to GLOF. These volcanic eruptions might displace the boundary or increase the pressure on the glacial lake or both.
- Heavy rainfall/melting of snow: This can lead to massive displacement of water in a glacial lake.
- Long-term dam degradation can also cause GLOF.
- Other reasons include the collapse of an adjacent glacial lake, etc.
Some significant glacial burst that occurred in the past:
The Glacial Lake Outburst Flood occurs all over the world except Australia (Glaciers are not found in Australia). Peru and Nepal in the past faced deadly or highly destructive glacial floods.
Dig Tsho glacial lake was present in Eastern Nepal (in a valley next to Mount Everest). In 1985 a GLOF occurred in Dig Tsho and brought out the dangerous potential of glacial lakes nationally and internationally. The Dig Tsho GLOF resulted in an estimated loss of US$ 1.5 million but fortunately only 4-5 casualties.
So far 14 GLOF events have been recorded in Nepal. In another ten events, the outburst occurred in Tibet (China) but it affected Nepal.
A flood caused by a GLOF in 1941 in Peru led to the death of an estimated 1,800. This event has been described as a historic inspiration for getting into research regarding GLOF.
In India, in 1929, a GLOF occurred from the Chong Khumdan Glacier in the Karakoram. It resulted into flood in the Indus River.
Vulnerability of Hindu Kush-Himalayan Region to Glacial Lake Outburst Flood(GLOF):
The Hindu Kush Himalayan (HKH) region is known as Asia’s water tower. It has the maximum snow cover after the poles. The Hindu Kush Himalayan region sustains more than two billion people directly and indirectly.
First, there are numerous glaciers in the HKH region. For example, there are 8,800 glacial lakes in the Himalayas and these are spread across countries. Among these, more than 200 of these have been classified as dangerous. These glacial lakes can trigger the Glacial outburst.
Second, the soil is getting loose in the HKH region. The large human settlements and human activities have resulted in deforestation and large-scale agricultural activities in the region. This intensifies the GLOF, as there is no natural barrier to control the flood.
Third, the factor of global warming and climate change. These are one of the most important reasons for the Glacial Lake Outburst Flood. Global warming and climate change lead to glacial retreat and glacier fragmentation (big glaciers splitting into smaller ones).
According to the Hindu Kush Himalaya Assessment report, even after fulfilling the commitments made under the Paris Agreement, one-third of the HKH region’s glaciers would melt and will potentially destabilize the river regime in Asia.
Fourth, the heat-island effect in the HKH region. The Himalayas are getting warm faster than other mountain ranges. This is due to the increase in the use of reinforced concrete (RCC) in building construction instead of eco -friendly traditional wood and stone masonry. This adds to regional warming and increases the number of glacial lakes or the water level of glacial lakes.
Fifth, tectonic activity in the region. The Indian plate is continuously moving towards north about 2 cm every year. So the Himalayas is rising about 5 mm a year. This makes the Himalayan region geologically active and structurally unstable. Landslides and earthquakes will continue to happen in the region. This can trigger a Glacial outburst.
For example, the entire State of Uttarakhand is categorized as Zone IV (High-Risk Zone) and V ( Very High-Risk zone) of the earthquake risk map of India.
Way forward:
First, a long-term solution will be feasible if all the countries start working towards reducing global warming.
Second, India needs to form clear policy guidelines to restrict further human activities like building roads, constructing hotels on banks, etc. Any further human activity without proper guidelines will harm the already fragile landscape.
Third, India needs to undertake a cumulative assessment and strategic planning. Geological Survey of India can use satellite images and technology like GIS (geographic information systems) and provide a clear analysis of the HKH region.
Fourth, Capacity building of the local community will ensure disaster mitigation in the near future.
Fifth, The government has to be proactive and set up an early warning system in the Himalayas. Like the one set up in coastal areas after the 2004 tsunami.
In conclusion, India is one of the most vulnerable countries to climate change and global warming. Even though international cooperation is required to restrict the global temperature to 1.5°C, India can move ahead and implement the suggestions. With this India can be a role model to the other countries in mitigating the disasters.
Glacial Lake Outburst Floods (GLOF)
What is the News?
Parts of Uttarakhand witnessed massive flooding due to Glacial Lake outburst.
What is Glacial Lake Outburst Floods(GLOF)?
- It is a type of outburst flood. It occurs when water dammed by a glacier is released. In other words, it’s an outburst that happens when a dam containing a glacial lake fails.
Note: An event similar to a GLOF, where a body of water contained by a glacier melts or overflows the glacier is called a jökulhlaup.
How does GLOF happen?
- Retreating glaciers, like several in the Himalayas, usually result in the formation of lakes at their tips, called proglacial lakes. It is often bound only by sediments and boulders.
- If the boundaries of these lakes are breached, it can lead to large amounts of water rushing down to nearby streams and rivers. It gathers momentum on the way by picking up sediments, rocks, and other material, and resulting in flooding downstream.
Features of GLOF: The three main features are:
- They involve sudden (and sometimes cyclic) releases of water.
- They tend to be rapid events, lasting hours to days.
- Furthermore, they result in large downstream river discharges (which often increase by an order of magnitude).
Causes behind GLOFs
The boundaries of glacial lakes breach due to multiple reasons. Like,
- A buildup of water pressure or structural weakness of boundary due to an increase in the flow of water.
- An earthquake (Tectonic) or cryoseism (non-tectonic seismic event of the glacial cryosphere) can also cause GLOF. During this, the boundary of the glacial lake will collapse suddenly and release the water in the glacial lake.
- An avalanche of rock or heavy snow: During this, the water in the glacial lake might be displaced by the avalanche.
- Volcanic eruptions under the ice can also cause GLOF. These volcanic eruptions might displace the boundary or increase the pressure on glacial lake or both.
- Heavy rainfall/melting of snow: This can lead to massive displacement of water in a glacial lake.
- Long-term dam degradation can also induce GLOF.
- Other reasons such as the collapse of an adjacent glacial lake, etc.
What are Glaciers?
- Glaciers are made up of fallen snow. It compresses into large, thickened ice masses over a period of time. They are formed when snow remains in one location long enough to transform into ice.
- Where are Glaciers found? Glaciers are found on every continent except Australia. Some are hundreds of thousands of years old. A large cluster of glaciers are in the Himalayas, which are part of India’s long northern border.
Source: The Hindu
Flash droughts in India
Why in News?
As per a new study, the number of flash droughts could be increased in India, by the end of this century.
Facts:
- Flash droughts: These droughts occur very quickly due to the rapid depletion of soil moisture. It is different from normal drought conditions, that develop in months, but the flash drought happens within a week or two.
- Factors: Several factors including Lesser precipitation, high temperature, anthropogenic greenhouse gas emissions play an important role in the occurrence of flash droughts.
- Flash droughts in India: The top five flash droughts in India based on the overall severity score occurred in 1979 (about 40% of the country was affected) followed by 2009, 1951, 1986, and 2005.
Key Takeaways from the study:
- The ongoing climate change has caused a significant increase in global temperature. It can lead to more and more flash droughts in the coming years.
- There is a five-fold rise in the frequency of extremely dry and hot years in the coming three decades. This is causing an approximately seven-fold increase in flash droughts like 1979, by the end of the 21st century.
- Impact: The increased frequency of flash droughts can have severe implications for crop production, irrigation demands, and groundwater abstraction in India.
Suggestions:
- Limiting Global Warming: By limiting global warming to well below 2 degrees C, the numbers and frequency of the projected flash droughts may go down.
- Predicting flash droughts: Flash-drought prediction ahead of time using operational meteorological forecasts will help manage irrigation water demands and avoid considerable losses in agriculture.
Source: The Hindu
Why lightning kills so many Indians?
News: According to a report, Lightning strikes have caused 1,771 deaths between April 1,2019 and March 31,2020 in India.
Facts:
- The report has been prepared by Climate Resilient Observing Systems Promotion Council(CROPC), a non-profit organisation that works with India Meteorological Department(IMD), Indian Institute of Tropical Meteorology(IITM), India Meteorological Society(IMS) and World Vision India to disseminate early lightning forecasts.
Key Takeaways:
- State Wise Deaths due to Lightning Strikes: Uttar Pradesh with 293 deaths, Madhya Pradesh 248, Bihar 221, Odisha 200 and Jharkhand 172 deaths together accounted for more than 60% of the numbers which are 33% of total fatalities from all natural disasters during the time period.
- Highest Lightning Strikes State: Odisha had 11.20 lakh plus lightning strikes—the highest in the country—with 200 casualties. During Cyclone Fani, the state saw more than one lakh intense lightning strikes in 2019.
- Deaths due to Lightning: The reason for death due to Lightning is because people are unaware and about 78% deaths took place due to people standing under isolated tall trees.About 22% of the people were struck in the open.
- Why are lightning strikes increasing? The report mentions that the lightning is direct promulgation of climatic extremities like global warming, deforestation, depletion of water bodies, concretisations, rising pollution and aerosol levels have cumulatively pushed the environment to extremes.
Recommendations:
- Lightning needs to be listed as a notified disaster by the Ministry of Home to get required attention in national policy directives and developmental programmes.
- Implement a local lightning safety action plan like installing Lightning Protection Devices.
- Need of Scientific and Community Centric approach: National Disaster Management Authority(NDMA) has issued guidelines for preparations of Lightning action plans to states.But the large number of fatalities show the implementation also needs a more ‘scientific and focused community centric approach’ as well as convergence of various departments.
- A National Lightning Resilience Programme is needed to identify the precise risk in terms of lightning frequency, current intensity, energy content, high temperature and other adverse impacts.
- Early lightning warning to farmers, cattle grazers, children and people in open areas.
Additional Facts:
- What is Lightning: Lightning is the process of occurrence of a natural electrical discharge of very short duration and high voltage between a cloud and the ground or within a cloud accompanied by a bright flash and sound and sometimes thunderstorms.
- Types: Inter cloud or intra cloud(IC) lightning which are visible and are harmless. It is cloud to ground (CG) lightning which is harmful as the ‘high electric voltage and electric current’ leads to electrocution.
- Technology: CROPC has a MOU with the India Met Department (IMD), Ministry of Earth Science(MoES) to disseminate early lightning forecasts which uses satellite observations, inputs from ‘network of Doppler and other radars’, ‘lightning detection Sensors’ among others.
- Origin of Lightning: Most Lightning strikes originate from Chotanagpur Plateau – the confluence of Odisha, West Bengal and Jharkhand—and extended to Bangladesh to Patkai plateau of Meghalaya affecting other North eastern states.
Geological Disaster
Industrial and Nuclear disasters
IFFCO gas leak: How dangerous is ammonia?
Source: The Indian Express
News: A major ammonia gas leakage at the Indian Farmers Fertilizer Cooperative Limited(IFFCO) unit at Prayagraj has occurred.
Facts:
- What is Ammonia? A tri-hydroid of nitrogen(NH3), ammonia is a building block for ammonium nitrate (NH4NO3) that is used in agriculture as a high-nitrogen fertiliser.
- Source of Ammonia: It is highly soluble in water, is found in soil, air, and water; it is naturally present in the body and secreted by the kidneys to neutralise excess acid.However, it is highly diluted when in the environment and does not affect the human body to a noticeable level.
- Acceptable Limit: The acceptable maximum limit of ammonia in drinking water as per the Bureau of Indian Standards is 0.5 ppm.
- Uses:
- Ammonia is stored for industrial use in liquid form under high pressure or in gaseous form at low temperature.
- Ammonia is critical in the manufacturing of fertilizers, and is one of the largest-volume synthetic chemicals produced in the world. More than 80% of ammonia made is consumed in the manufacturing of fertilizer and most of the remainder goes into the production of formaldehyde.
- How is it harmful on Human Body?
- Ammonia interacts immediately upon contact with moisture present in the skin, eyes, oral cavity, respiratory tract to form ammonium hydroxide which is very caustic and disrupts the cell membrane lipids ultimately leading to cellular destruction.
- If Ammonia is inhaled in excess, the gas is toxic and affects the lungs with a possibility of causing chemical pneumonitis — inflammation of the lung caused by aspirating or inhaling irritants.
Accident and Biological disaster
Link between Dam and Natural disasters – Explained Pointwise
Table of contents:
Rishiganga dam in Uttarakhand was recently destroyed by the Glacial Lake Outburst Flood and intensified the GLOF in the region. This is not the first time a Dam is aiding and intensifying the disaster in India. It can be a potential hazard to both human life and the environment. This raises a larger question on the net benefit of big dams.
What is Dam?
It is a structure built across a stream or river to hold back water. There are many reasons to build a dam. Such as,
How dams are aiding disasters?
Dams were built to provide benefits to human. But many times instead of providing benefits, dams are harming the region by aiding a disaster. The reasons are:
- Dams as a hydropower plant: Construction of hydro-power plant requires diversion of rivers through tunnels to generate power. The construction of these tunnels unsettles the mountainous terrain by displacing the supportive sediment. It results in the slipping down of rocks due to the removal of their support system (Landslides).
- Dams as a reason for frequent floods: Due to poor maintenance, siltation, etc. dams are not able to hold adequate water. This is responsible for the increasing frequency of floods in India.
- Dam as a solution to prevent/divert large run-off water: To protect the river run-off, many bigger dams have been constructed in highly vulnerable locations, like the Himalayas. For example, the entire state of Uttarakhand is vulnerable to earthquakes, but there are large dams planned in the fragile region that disturb the ecosystem. Dams in these locations aggravate the natural disaster.
- Dams as a reason for an earthquake: When a large quantity of water is loaded and unloaded frequently in the region, it might lead to reservoir induced seismicity. For example, Koyna earthquake of December 1967.
All these reasons lead to dam failure. This is then followed by a large-scale release of water, downstream of the river and creating floods. This will create economical, infrastructural, environmental, and livelihood losses.
Dams aided disasters in the past:
- The worst dam disaster in India was the Machu dam failure (Gujarat) in 1979. The torrential rainfall in the area created a large scale flood and a failure in the dam. According to the official estimates, around 2000 people had lost their lives.
- In August 2018 Kerala witnessed its worst floods since 1924 due to the torrential rainfall. Too much water stored in the dam aggravated the disaster. At least 35 of 50 large dams had been opened for releasing water in to the already flooded areas. The flood took the lives of around 503 people in the state.
- Similarly, in 2019 heavy rain caused a breach in Tiware dam (Maharastra). This led to the flooding of seven villages and 20 people swept away.
- Most recently, a Glacial Lake Outburst Flood destroyed the Rishiganga dam. This led to a large surge of water downstream which breached the Tapovan Hydropower Plant.
Vulnerability of Indian dams:
- India has more old dams. India in total has 5,745 reservoirs in the country, of which, 293 are more than 100 years old. The age of 25% of the dams is between 50 and 100 years and the remaining 80% are over 25 years old. Ageing dams face the following issues,
- Differential settlement of foundation in the dam,
- Clogging of filters, increase of uplift pressures,
- Cracks in the dam core,
- Loss of bond between the concrete structure and embankment,
- Reduction in slope stability in earthen and rockfill dams,
- Erosion of earthen slopes,
- Deformation of the dam body itself.
All these aids the intensification of any disaster.
- Many dams have structural deficiencies and shortcomings in operation and monitoring facilities. Few dams not even meet the present safety standards on structural and hydrological conditions.
- Many states are not providing sufficient budgets for the maintenance and repair of the dam. There is also a lack of institutional and technical capacities for addressing dam safety issues. For example, According to Central Water Commission data, “Not even a single dam in Kerala was inspected before monsoon during Kerala floods”.
- The current legal framework does not have any provision for penalizing the person/trust/state responsible for dam failure.
- Real-time inflow forecasting systems are not in place even in important reservoirs. This creates vulnerability to dam safety and dam operation.
Government Initiatives to improve dam safety:
- Dam Rehabilitation and Improvement Project (DRIP)
- It is a World Bank assisted project. The project aims to improve the safety and operational performance of selected existing dams and associated appurtenances sustainably.
- Ministry of Water Resources, River Development & Ganga Rejuvenation through the Central Water Commission, is implementing the project.
- Dam Safety Bill, 2019.
- The Bill provides for proper surveillance, operation, inspection, and maintenance of all specified dams in the country.
- The Bill aims to constitute the National Committee on Dam Safety. The committee shall suggest dam safety policies and also recommend any necessary regulations.
- The Bill also establishes the National Dam Safety Authority. The NDSA is a regulatory body that discharges functions to implement the policy, guidelines, and standards in the country.
- The Bill also provides for the constitution of a State-level Committee on Dam Safety by State Governments.
- Dam Health And Rehabilitation Monitoring Application (DHARMA)
- It is a web-based software package. It supports the effective collection and management of Dam Safety data in all large dams of India.
- The major aim of DHARMA is to digitize all dam related data.
- Seismic Hazard Assessment Information System (SHAISYS) for mapping Seismic Hazards.
Suggestions to make dams disaster-resilient:
- State governments should strictly follow the dam safety manual.
- Creation of the buffer zone: States have to ensure that there is no encroachment in the nearby area.
- Need to integrate urban-rural planning with dam safety. Since India is a populous country, it is impossible to shift people during calamities. Proper dissemination of information on a real-time basis and regular flushing of water has to be carried out downstream to keep the river beds dry. This can be done only through an integrated approach.
- A Standing Committee recommended a penal provision for dam failures on authorities. The government has to incorporate this into law. Along with that, the government has to increase the capacity building of locals and associated institutions.
- The government has to create a well-planned monitoring system using modern instruments. This is the key to the early detection of defects and averts disasters.
The government must consider the issue holistically and avoid building large dams for political gains in fragile regions. The construction of a dam is not a disaster, but the mismanagement and poor planning of the dam is a disaster which affects all of us in a severe manner. It is a high time for the government to understand this.