Simulating the Hydrologic Response to Climate Change: Sani River Basin, Gujarat (India)

Climate change is expected to create many challenges (water availability) worldwide and projecting its impacts at regional scale allows communities to be proactive in planning for the future. It will help to prepare a future plan for the water resources development and management for the basin. The study was planned for estimating the runoff, evapotranspiration and groundwater recharge by SWAT model and assessing the impacts of climate change on potential surface and ground water resources of basin. The study was undertaken in Sani river basin of Devbhumi Dwarka district which is located in Gujarat state, India. The digital data of various remote sensing satellite images of river basin required for work were collected from BISAG, Gandhinagar. The historical observed hydro- meteorological data (1961-2005) were collected from the State Water data Centre, Gandhinagar and Millet Research station, JAU, Jamnagar. The simulated daily precipitation and daily maximum and minimum temperature for the period of 1951-2005 (control period) and 2006-2100 (future scenarios) by EC-Earth RCM for RCP 4.5 were collected from the IITM, Pune, Maharashtra. The bias corrected simulated data by the RCM was used as inputs for the simulating the hydrologic response of basins by SWAT model. The different water balance components like runoff, evapotranspiration and groundwater recharge for the basins were estimated from the SWAT simulations results. The impacts of climate change water balance components were assessed through the trend analysis using Mann-Kendall method and Sen’s slope method. The rainfall, runoff, evapotranspiration and groundwater recharge were found stable in past and will be stable in future too, as there will not be climate change impacts on it for the basin. However, the temperature and reference evapotranspiration were found increasing in the basin.