6-Development of a Simplified Drought Index and its Comparison with Standardized Precipitation Index.

Abstract

In a river basin with predominantly agricultural activity, management of limited water resources is very vital for sustainable development. Here drought research plays an important role in studying water deficits, so that better management of water resources' in the basin can be ensured This research was undertaken for the Upper Kansabati River Basin in West Bengal State of eastern India. It focused on development of a simplified drought index called Precipitation Index (PI) and its comparison with the generally accepted Standardized Precipitation Index (SPI). Both these drought indices are computed entirely based on precipitation data. Precipitation Index (PI) facilitates simpler calculation as compared to the Standardized Precipitation Index (SPI) while maintaining the advantage of SP! having a variable time scale. The results indicate that the PI values show almost the same trend as the SPI values for all time scales. However, unlike the SPI-based drought classes, the PI-based drought classes become mare and more clustered with the increase in time scale. The computational simplicity of the PI makes it very easily applicable. However further studies are needed to establish the utility of PI for other river basins of different sizes in different hydro-meteorological regions within and outside India.