25. Impact of Climate Change on Flood and Drought Management

Floods and droughts pose serious hazards to human populations in many parts of the world. Because of large diversity in climatic conditions over the country, India is a flood prone as well as a drought prone country. During last two decades, global warming due to anthropogenic-driven emissions of greenhouse gases has emerged as one of the most important environmental issues ever to confront humanity. Under changed climatic scenarios a number of chain events, like melting of glaciers, sea level rise, submergence of islands/coastal areas and deviant rainfall patterns, are likely to occur. Likely impacts would include a greater annual variability in the monsoon's precipitation levels, leading to more intense floods and droughts. Thus, climate change in future is expected to have implications on river flows in South Asia including India. Global climate change is likely to result in severe droughts and floods in India, with major impacts on human health and food supplies. Developing countries of temperate and tropical Asia already are highly vulnerable to the extreme climate events such as floods, droughts and cyclones. Climate change and variability would exacerbate these vulnerabilities. Annual and seasonal changes in climate would alter the frequency and severity of major droughts. Changing temperature and evaporation rates would alter soil moisture conditions and the amount of runoff from the catchments into reservoirs. There are some evidences of increases in the intensity or frequency of some of these extreme events on regional scales throughout the 20th century. The abnormalities generated due to climate change are likely to trigger shifts in existing biodiversity patterns and demands for totally new set of land uses. The growing frequency and magnitude of extreme environmental events worldwide has intensified research interest in natural disasters as well as regional vulnerability and response capabilities.