Impact of Climate Change on Hydrological Regime in Sabari sub-Basin, Godavari River System, India

Abstract

Climate change is an issue of great concern to a developing country like India. India needs to be much more concerned since its vast population largely depends on climate sensitive sectors like hydrology, agriculture, forestry and fishery for livelihood. In these circumstances a study has been carried to find out the impacts of climate change in Sabari sub-basin which involves rainfall-runoff modeling using PRECIS model data. The daily rainfall-runoff modeling was carried out using ARNO model for a period of 39 years (1970 to 2008). Out of 39 years calibration and validation was carried out for a period of 30 years (1970 to 1999) and 9 years (2000 to 2008) respectively. The Regional Climate Model (RCM) data supplied by PRECIS model which have a grid cell size of 50 km X 50 km and contains three different scenario periods i.) Base line period (1961 to 1990) ii.) Mid Century Period (2021 to 2050) and iii) End century period (2071 to 2098). The observed IMD and predicted RCM downscaled data for the base line period (1960-1990) has been compared and found that there is a huge variation in both the temperature and rainfall measurements. Analysis of RCM data reveals that the temperature is alarmingly increasing during the Mid Century and End Century periods. The futuristic hydrological scenarios have been arrived by incorporating the downscaled RCM data with the calibrated ARNO model. From the analysis it is opined that climate change may pose frequent high peak floods that occurs in a short period of time may alter the landuse/lancover conditions and agricultural patterns in the study area.