Flood Vulnerability of Assam

Assam which is traditionally been flood-prone is in the grip of yet another flood, with 57 lakh people displaced, all 33 districts affected, and 36 people killed besides hundreds of animals.

Vulnerability of Assam

Assam’s vulnerability to floods has contributing factors from both natural and man-made causes. The crux of which is the nature of the river Brahmaputra which is dynamic and unstable.

• River Brahmaputra originates in Tibet. The region is cold, arid and lacks plantation. Glaciers melt, soil erodes and all of it results in a highly sedimented river.
• River Brahmaputra features among the world’s top five rivers in terms of discharge as well as the sediment it brings.
• Two spots Bahadurabad of Bangladesh and  Pandu of Guwahati in Assam were ranked at second and third places in terms of sediment yield in 2008.
• River Brahmaputra enters floodplains in Assam. These floodplains are surrounded by hills on all sides. As the river comes from a high slope to a flat plain in Assam, its velocity decreases suddenly and this results in the river unloading the sediment.
• Further due to the earthquake-prone nature of the region, the river has not been able to acquire a stable character.
• The man-made ones such as habitation, deforestation, population growth in catchment areas are also leading to higher sedimentation.

Tackling the Problem

• In the master plan, the Brahmaputra Board had suggested the construction of dams and reservoirs to mitigate floods.
• But it can be a double-edged sword as sometimes the discharge during heavy rains would be beyond the capacity of the channels downstream.
• There is also protests by the residents and environmentalists due to fear of submergence.
• As a result, the government has been using only one approach towards floods: building embankments on the river. But their durability is a serious matter of concern.

Sustainable Solution

For a sustainable solution, there is a need for “a basin-wide approach” with an “integrated basin management” system. This integrated management system must bring in all the basin-sharing countries on board. “

Addressing the issues only in Assam when the flood strikes isn’t the solution and all states must come to an understanding about taking measures in the catchment areas. This requires robust interstate relationships, political cooperation and the role of the government are important.

India can also learn from flood-plain zoning, which is done in the US. Under flood-plain zoning depending on the vulnerability of the area, the flood plain is divided into categories, and accordingly, certain activities are banned on it: like farming, building a house etc.