Basin-wide assessment of temperature trends in northwest and central India

Abstract

Estimates of trends of climatic changes at basin and state scales are required for developing adaptation strategies related to planning, development and management of water resources. In the present study, seasonal and annual trends of changes in maximum temperature (Tmax), minimum temperature (Tmin), mean temperature (Tmean), temperature range (Trange), highest maximum temperature (Hmax) and lowest minimum temperature (Lmin) have been examined at the basin scale. The longest available records over the last century, for 43 stations covering nine river basins in northwest and central India, were used in the analysis. Of the nine river basins studied, seven showed a warming trend, whereas two showed a cooling trend. The Narmada and Sabarmati river basins experienced the maximum warming and cooling, respectively. The majority of basins in the study area show increasing trend in Trange, Hmax and Lmin. Seasonal analysis of different variables shows that the greatest changes in Tmax and Tmean were observed in the postmonsoon season, while Tmin experienced the greatest change in the monsoon season. This analysis provides scenarios of temperature changes which may be used for sensitivity analysis of water availability for different basins, and accordingly in planning and implementation of adaptation strategies.