Eight major river basins, many of them originating in neighboring Nepal, flow across the northern part of the Indian state of Bihar, a state where 6.6 million hectares of landmass (70.6% the total area of the state) is prone to recurring floods. The rivers erode the soil easily as they traverse downwards, and deposit them in the Bihar plains, before draining into the River Ganga. The deltas created by the avalanche of sediments often provoke the rivers to meander off their usual course and flood the plains.
For instance, the man-made embankments along the two sides of the Kosi River hem in nearly 1.5 million people spread over 414 villages across south Nepal and north Bihar. In August 2008, a wide breach in this embankment in south Nepal caused massive destruction and loss of lives of humans and livestock, compelling the Indian Government to declare the floods a ‘National Calamity’.
Scientific studies suggest that glacier melt in the Himalayas is projected to increase flooding and affect the availability of water resources within the next two to three decades. This will be followed by decreased river flows as the glaciers recede. Freshwater availability in South Asia, particularly in the large river basins, is projected to decrease due to climate change which, along with population growth and increasing demand arising from higher standards of living, could adversely affect more than a billion people by the 2050s.
Vulnerability of select marginalized communities to the impact of floods has been the result of many socio-economic, cultural and political factors, as well as environmental stress. In the areas most prone to floods, large populations continue to live in or near their villages, with limited protection and virtually no support services simply due to lack of adequate rehabilitation measures. Coupled with factors like social exclusion of the certain communities based on caste and gender inequality, unequal access to resources and food insecurity, their capacity to adapt has been severely hampered.
Conflict and forced migration have been the spontaneous responses in the absence of adequate State initiatives and local institutional support for the most disadvantaged groups.