Spatial and temporal drought analysis in the Kansabati river basin, India

The identification, monitoring and characterization of droughts are of great importance in water resources planning and management. To investigate the spatial and temporal relationships of drought occurrence, the Standardized Precipitation Index (SPI) (calculated from the probability distribution of precipitation using a two-parameter gamma function) was used. The SPIs were applied at the local scale using monthly rainfall data for the period of 1965-2001 from five raingauge stations in the basin. The basin is divided into 25 grid-cells of 13 x 13 km with each grid correspondence to approximately 4% of total area. The inverse distance weighting (IDW) approach is used for the spatial interpolation of rainfall at each grid point. Drought severity is then assessed from the estimated gridded SPI values at multiple time scales. The spatial and temporal characteristics of SPI are used to develop drought severity - area - frequency curves that can assess the severity of the localized drought within the basin. The analysis of SPI suggests that the basin endured severe drought during the 1980' s. These frequency curves can be used for planning sustainable water resources projects within the basin.