Natural Hazards of Assam

Assam and Entire North Eastern India has a unique and unstable geological Conditions which makes it prone to various natural disasters and also Assam has witnessed some of the hazards or disasters which are due to anthropogenic reasons. Disasters causes disruption to life and property and creates a havoc among the people. Disasters wash away the gains of development and not only Human beings are affected but also entire Biodiversity-2/”>Biodiversity is affected. For Ex- recent floods in Assam cause a lot of damage to the Population of Rhinos in Kajiranga National Park.

A review of the past disasters indicates that the state had to bear the devastations of two natural disaster floods and earthquake.

Natural Disasters

Earthquakes
Floods
Landslides
Erosion
Wind and Cyclone
Fire

Earthquakes

As per the Tectonic Theory of Plates, Assam lies in the eastern part of the Indian Plate. This is the point where the Indian plate is thrusting underneath the Eurasian Plate creating a subduction zone. This makes the state of Assam fall under the seismic zone V which makes the entire State prone to earthquake of moderate to very high intensity. Among the large earthquakes in this region were the events in 1869 and 1897. The 1897 earthquake is well known for the dramatic accounts of violent up throw during the shock.

Combined with this hazard, the haphazard and uncontrolled Growth of cities has made things worse. There is a famous Japanese proverb that Earthquakes do not kill people buildings do. Rising Urban population combined with poor quality and ill-maintained Infrastructure-2/”>INFRASTRUCTURE without following Zonal and Building regulations increases the risks to earthquakes in the urban centres. Moreover, urban infrastructure is often designed and constructed without satisfying minimum safety standards.

Flood

Assam lies in the middle of the Brahmaputra and Barak basins. The Brahmaputra basin is one of the largest river basins in the northeast region of India. The Brahmaputra Valley in Assam is one of the most hazard-prone regions of the country, with more than 40% of its land (3.2 million hectares) susceptible to flood damage. This is 9.4% of the country’s total flood-prone area. About 7% of land in the state’s 17 riverine districts has been lost because of river erosion over the past 50 years.

Flood hazard risk in the state is due to a blend of numerous natural and anthropogenic factors. The important cause for frequent occurrence of flood in this region is the extremely dynamic monsoon rainfall regime and the unique physiographic setting.

The water yield of the Brahmaputra basin is among the highest in the world. This, together with the limited width of the valley and the abruptly flattened gradient, leads to tremendous drainage congestion and resultant flooding. The Brahmaputra valley had experienced major floods in 1954, 1962, 1966, 1972, 1974, 1978, 1983, 1986, 1988, 1996, 1998, 2000 and 2004.

The floods are caused by the runoff of extremely heavy rainfall during the monsoon and high sediment loads from upper watersheds that are geologically unstable and degraded because of deforestation and changing land use. The flood combined with river erosion has significant impacts each year.

Landslide

Landslides are sudden, short-lived geomorphic event that involves a rapid-to-slow descent of Soil or rock in sloping terrains. It can also be caused by excessive Precipitation or human activities, such as deforestation or development that disturb natural slope stability. Landslides are caused when the stability of a slope changes from a stable to an unstable condition. A change in the stability of a slope can be caused by a number of factors, acting together or alone.

Assam is located on the Himalayas, which are the recent foundation of mountain history and are geologically unstable; they are seismically very active therefore are still in the upheaval stage . As mentioned the state has a history of earthquakes. These earthquakes are usually accompanied by damaging landslides in the region .

Erosion

The Brahmaputra basin is an example of an extremely heterogeneous watershed with complex topography, high spatial variability in land cover. Additionally, the Climate is complex within the catchment because of the altitudinal range, the geographical location and the influence of the South Asian monsoon systems. Further, the tectono-sedimentary province along the Brahmaputra river valley in the state of Assam is near about 720 km long and 90 km wide with high variation in elevation which is home for nearly 26 million people.

The above factors give rise to riverbank erosion which has been a regular phenomenon in Assam. Erosion history of Assam indicates that between 1912 and 1996 around 868 sq.km. of land was lost to bank erosion; averaging to about 10.3 sq. km. of area lost per year.

Further, significant erosion occurred in Assam due to Brahmaputra river between 1914 to 1975. The bank line of the Brahmaputra is extremely unstable consisting mostly of fine sands and silts. Large scale slumping of river banks does take place when the level falls after a flood. Further, the braided nature of the Brahmaputra adds unpredictability to erosion problem making it more serious.

The extent of loss to the bank erosion varies from year to year depending on the severity of floods in the state. Majuli, the largest river island in the world is now seriously affected by the erosion and is facing the threat to existence.

Wind and Cyclone

Assam is situated in the north eastern direction of Bangladesh which is highly prone to cyclone/winds. Every year about 60% of the area affect by cyclone in Bangladesh.

Due to the location aspect, districts like Dhubri, Gaolpara, Hailakandi, Chachar and Karbi Anglong are more prone to cyclone/winds. Districts namely Kokrajhar, Bongaigaon, Kamrup, Barpeta, Nalbari, Darrang, Sonitpur, Nagaon, Marigaon, Lakhimpur, Dhemaji, Sibsagar, Jorhat, Golaghat, Dibrugarh, Tinsukia and Karbi Anglong are likely to experience wind speed of 50 m/s whereas districts like Hailakandi, Karimganj and Cachar has wind speed of more than 55m/s and are more vulnerable to cyclonic storms.

Occasional Cyclones-2/”>Cyclones do occur in western Assam their severity is more during monsoon. According to BMTPC cyclone zonation, north-west districts of Assam lying in zone of high damage where wind speed can reach up-to 47

m/s. District very close to Bangladesh are in very high damage zone due to close proximity of Bay of Bengal (which is a cyclone basin). In this zone wind speed can reach up-to 55 m/s, can resultant into large scale damage.

Impact of Climate Change on Assam

The north-eastern region of India is expected to be highly prone to the consequences to climate change. The annual mean maximum temperatures in the region are rising at the rate of +0.11°C per decade. The annual mean temperatures are also increasing at a rate of 0.04°C per decade in the region.

The State of Assam is very much a part of the regional warming trend. However, there is no significant trend in rainfall for the region as a whole i.e. rainfall is neither increasing nor decreasing appreciably for the region as a whole. The summer monsoon rainfall is found to be decreasing over this region significantly during the last century at an approximate rate of 11mm per decade.

Extreme precipitation events (heavy rain storm, cloud burst) may have their own impacts on the fragile geomorphology of the Himalayan part of the Brahmaputra basin causing more widespread landslides and soil erosion. The response of hydrologic systems, erosion processes, and sedimentation in the Himalayan river basins could alter significantly due to climate change. Glacial Recession is also linked to increased sediment load in rivers.

A number of major flash floods have occurred in this decade due to heavy rainstorms or cloud bursts in the state or in the upper catchments of the rivers in the neighboring states (Meghalaya, Arunachal Pradesh) and highlands in other countries (Bhutan, China).

The southern part of Nagaon district in central Assam valley and adjoining parts of Karbi Anglong form a rain-shadow zone where annual rainfall is as low as 800-1200 mm. Water scarcity is a potential constraint for the people living in these areas. Absence of effective Irrigation systems or water harvesting practices adds to the vulnerability of the people. Lumding, located centrally in this zone shows a decline in rainfall at a rate of 2.15 mm per year. As a result water crisis might aggravate in this region in the coming years.

Institutional Framework and their roles and responsibilities

Roles and Responsibilities of State level arrangements

Assam State Disaster Management Authority

The Assam State Disaster Management Authority is constituted under the

chairmanship of the Chief Minister and other members will ensure interdepartmental coordination covering all aspects of DM. The State Authority has the responsibility of laying down policies and plans for DM in the State, recommend the provision of funds for mitigation and preparedness measures, review the development plans of different departments of the State and ensure that prevention and mitigation measures are integrated therein and issue necessary guidelines or directions as may be necessary.

State Executive Committee

The State Executive Committee (SEC) is constituted under the chairmanship of the Chief Secretary to the Government of Assam will assist the State Authority in the performance of its function and coordinate action in accordance with the state guidelines laid down by the State Authority and ensure the compliance of directions issued by the State Government under the Act.

Roles and Responsibilities of District level arrangements

District Disaster Management Authority

The District Disaster Management Authority constituted for every district in the

State is under the chairmanship of the Deputy Commissioner. The District

Authority shall act as the district planning, coordinating and implementing body for DM and take all measures for the purposes of DM in the district as per the guidelines laid down by the National and State Authority.

The District Authority will prepare the District Disaster Management Plans, review capabilities and preparedness measures, give directions to the concerned departments at the district level, organize and coordinate specialized training programmes for different level of officers, employees, voluntary rescue workers and take all such measures as may be appropriate for a holistic and pro-active approach to DM.

Roles and Responsibilities of Local level arrangements

Local Authorities

The local authorities include the PRIs, Municipalities, Urban Local Bodies,

Cantonment boards etc. the local authority will ensure that its officers and employees are trained for disaster management, Resources relating to DM are so maintained as to be readily available for use in the event of any disaster situation; construction practices under it or within its jurisdiction confirm to the standards and specifications laid down for prevention of disaster and mitigation; and carrying out relief, rehabilitation and reconstruction activities in the affected areas in accordance with the State Plan and the District Plan.

Disaster Management Plan

As per the DM Act 2005, Disaster Management means a continuous and integrated process of planning, organizing, coordinating and implementing measures which are necessary or expedient for-

Prevention of danger or threat of any disaster
Mitigation or reduction of risk of any disaster or its severity or consequences;
Capacity-building;
Preparedness to deal with any disaster;
Prompt response to any threatening disaster situation or disaster;
Assessing the severity or magnitude of effects of any disaster;
Evacuation, rescue and relief;
Rehabilitation and reconstruction;

Disaster Management plan at all levels will be drawn upon at the Local, District and State levels as well as by relevant departments with a mandate for DM functions to ensure coordination and holistic response to disaster. The plans will incorporate the inputs of all stakeholders for integration into the planning process.

List of ongoing initiatives

ASDMA has undertaken various activities to build a disaster resilient state. The list highlights select activities and is not exhaustive.

Flood early warning system (FLEWS)
Hazard Risk and Vulnerability Assessment
Revision of Assam Relief Manual (1976), renamed as Disaster Management Manual
Setting up of Disaster Information and Response Centre at Revenue Circle Level
Involvement of NGO’s and Ex-Service men in DM
Integration of Emergency Helpline Numbers
Revisiting the danger levels of major rivers of Assam
Equipping the Districts for better response during floods
Capacity building and awareness generation
Trainings and workshops for stakeholders (engineers, architects, doctors, PRIs, NGOs, volunteers in first aid & search and rescue)
State wide school safety programme
Technical projects undertaken by knowledge institutions in the State
Establishment of Assam Institute of Disaster Management (AIDM)\

Assam is a state in north-eastern India that is prone to a number of natural hazards. These include earthquakes, floods, landslides, droughts, wildfires, cyclones, Tsunamis, epidemics, and famine.

Earthquakes are a common occurrence in Assam, as the state lies on the Indo-Australian Plate, which is colliding with the Eurasian Plate. The most recent major earthquake in Assam was the 1950 Assam earthquake, which had a magnitude of 8.6 and caused widespread damage and loss of life.

Floods are also a major hazard in Assam, as the state is located in the Brahmaputra River basin. The Brahmaputra is one of the world’s largest rivers, and it is prone to flooding during the monsoon season. The 2012 Assam floods were the worst in recent history, affecting over 2 million people and causing billions of dollars in damage.

Landslides are another major hazard in Assam, as the state is located in a mountainous region. Landslides are often triggered by earthquakes, heavy rains, or deforestation. The 2014 Guwahati landslide was one of the deadliest landslides in recent history, killing over 100 people.

Droughts are also a major hazard in Assam, as the state receives relatively low rainfall. Droughts can lead to crop failures, water shortages, and Livestock deaths. The 2015 Assam drought was one of the worst in recent history, affecting over 10 million people.

Wildfires are also a major hazard in Assam, as the state is located in a tropical climate. Wildfires are often triggered by dry weather conditions, lightning strikes, or human activity. The 2012 Assam wildfires were the worst in recent history, burning over 100,000 hectares of forest.

Cyclones are also a major hazard in Assam, as the state lies on the Bay of Bengal. Cyclones are tropical storms that can cause widespread damage and loss of life. The 2014 Assam cyclone was one of the worst in recent history, affecting over 1 million people and causing billions of dollars in damage.

Tsunamis are also a major hazard in Assam, as the state lies on the Indian Plate, which is an active tectonic plate. Tsunamis are large waves that can be caused by earthquakes, volcanic eruptions, or landslides. The 2004 Indian Ocean tsunami was one of the deadliest natural disasters in history, affecting over 230,000 people in India and neighboring countries.

Epidemics are also a major hazard in Assam, as the state has a large population and a high rate of POVERTY. Epidemics are outbreaks of infectious diseases that can spread rapidly through a population. The 2014 Assam cholera outbreak was one of the worst in recent history, affecting over 100,000 people and causing over 1,000 deaths.

Famine is also a major hazard in Assam, as the state is prone to droughts and floods. Famine is a widespread shortage of food that can lead to starvation and death. The 1943 Bengal famine was one of the deadliest famines in history, affecting over 3 million people in India and neighboring countries.

Man-made disasters are also a major hazard in Assam, as the state is located in a region with a history of armed conflict. Man-made disasters are disasters that are caused by human activity, such as wars, industrial accidents, or terrorist attacks. The 2014 Guwahati gas leak was one of the worst man-made disasters in recent history, killing over 100 people.

Assam is a state that is prone to a number of natural and man-made hazards. The state government has taken a number of measures to mitigate the risks posed by these hazards, but more needs to be done to ensure the safety and security of the people of Assam.

What are the most common natural hazards in Assam?

The most common natural hazards in Assam are floods, earthquakes, and landslides.

What are the causes of floods in Assam?

The causes of floods in Assam are:

Heavy rainfall
Melting of snow in the Himalayas
Deforestation
Indiscriminate construction of Dams and embankments

What are the effects of floods in Assam?

The effects of floods in Assam are:

Loss of life and property
Damage to infrastructure
Disruption of agriculture
Spread of diseases

What are the causes of earthquakes in Assam?

The causes of earthquakes in Assam are:

The movement of tectonic plates
The presence of faults in the earth’s crust

What are the effects of earthquakes in Assam?

The effects of earthquakes in Assam are:

Loss of life and property
Damage to infrastructure
Disruption of agriculture
Spread of diseases

What are the causes of landslides in Assam?

The causes of landslides in Assam are:

Heavy rainfall
Deforestation
Indiscriminate construction of roads and buildings

What are the effects of landslides in Assam?

The effects of landslides in Assam are:

Loss of life and property
Damage to infrastructure
Disruption of agriculture
Spread of diseases

What are the preventive measures that can be taken to reduce the impact of natural hazards in Assam?

The preventive measures that can be taken to reduce the impact of natural hazards in Assam are:

Early warning systems
Disaster preparedness plans
Land use planning
Infrastructure Development
Reforestation
Awareness campaigns

What are the rehabilitation measures that can be taken to help the people affected by natural hazards in Assam?

The rehabilitation measures that can be taken to help the people affected by natural hazards in Assam are:

Food and shelter
Medical care
Cash assistance
Reconstruction of houses and infrastructure
Psychological support

Sure, here are some MCQs on the topics of natural hazards, earthquakes, and tsunamis:

What is a NATURAL HAZARD?
(A) A natural event that can cause loss of life, damage to property, or disruption of Society
(B) A natural event that is caused by human activity
(C) A natural event that is not caused by human activity
(D) A natural event that is not a threat to humans
What is an earthquake?
(A) A shaking of the ground caused by the sudden release of energy in the Earth’s crust
(B) A movement of the Earth’s crust that causes the ground to shake
(C) A wave that travels through the Earth’s crust and causes the ground to shake
(D) A natural disaster that is caused by earthquakes
What is a tsunami?
(A) A series of waves that are caused by an earthquake or volcanic eruption
(B) A large wave that is caused by an earthquake or volcanic eruption
(C) A wave that travels through the ocean and causes the water to rise
(D) A natural disaster that is caused by tsunamis
What are the effects of earthquakes?
(A) Damage to property, loss of life, and disruption of society
(B) Damage to property, loss of life, and disruption of the Environment
(C) Damage to property, loss of life, and disruption of the economy
(D) Damage to property, loss of life, and disruption of all aspects of society
What are the effects of tsunamis?
(A) Damage to property, loss of life, and disruption of society
(B) Damage to property, loss of life, and disruption of the environment
(C) Damage to property, loss of life, and disruption of the economy
(D) Damage to property, loss of life, and disruption of all aspects of society
What are some ways to protect yourself from earthquakes?
(A) Build your home on solid ground
(B) Install a home earthquake-warning system
(C) Have a plan for what to do in the event of an earthquake
(D) All of the above
What are some ways to protect yourself from tsunamis?
(A) Live in a tsunami-safe zone
(B) Have a plan for what to do in the event of a tsunami
(C) Know the evacuation routes in your area
(D) All of the above
What is the difference between an earthquake and a tsunami?
(A) An earthquake is a shaking of the ground, while a tsunami is a series of waves
(B) An earthquake is caused by the sudden release of energy in the Earth’s crust, while a tsunami is caused by an earthquake or volcanic eruption
(C) An earthquake can cause damage to property and loss of life, while a tsunami can cause damage to property, loss of life, and disruption of society
(D) All of the above
What is the Richter magnitude scale?
(A) A scale that measures the strength of earthquakes
(B) A scale that measures the height of tsunamis
(C) A scale that measures the damage caused by earthquakes
(D) A scale that measures the damage caused by tsunamis
What is the Mercalli intensity scale?
(A) A scale that measures the strength of earthquakes
(B) A scale that measures the height of tsunamis
(C) A scale that measures the damage caused by earthquakes
(D) A scale that measures the damage caused by tsunamis

I hope these MCQs were helpful!