Hydrological Modeling of Natunhat Watershed, West Bengal of the Ajay River Catchment under Changed Climate Scenario

摘要

It is known tliat variability of climate has a pronounced impact on water supplies, instream conditions, aquatic habitat, flora and fauna. Global warming is altering ecology in complex ways. A study of soil moisture accounting parameters was conductedfor the Ajay river catchment on the Natunhat watershed, Wes( Bengal, to determine the water availability scenario under a climate change scenario. The key impacts of climate change in ecological and hydrological systems need to be assessed for future flow regimes. A distributed hydrological model HEC-HMS was used to quantify the impact of climate change on the water resources of the Ajay river catchment outlet at Natunha, after calibration using historical data and a GIS coupled with RS techniques. Thestudy uses the HadRm daily weather data to determine the control (present) and GHG (future) water availability in space and time. A total of 15 years of simulation spanning the entire Ajay river catchment has been conducted. Five years were devoted to control (present) 1997-2001 and the remaining 10 years (2040-2050) devoted to GHG (future) climate scenario. Soil evapotranspiration, soil infiltration and canopy overflow are seen to decrease whereas canopyevapotranspiration Increases over the projected period. Streamflow is seen to decrease by a maximum of 82.24% over the projected period of 2041-50 during the changed climate scenario.