Abstract

The temporal and spatial characteristics of meteorological drought are investigated to provide a framework for sustainable water resources management in the Parambikulam-Aliyar river basin. Using the Standardized Precipitation Index (SPI) as an indicator of drought severity, the characteristics of droughts are examined. Parambikulam-Aliyar basin was divided into 97 grids of 5×5 km and monthly rainfall data for the period of 1972–2011 from 28 rain gauge stations were used for spatial interpolation of rainfall using inverse distance weighting approach. Temporal characteristics of drought were assessed using regional representative of SPI values calculated from spatially averaged gridded rainfall at 12-month time scales. Spatial characteristics of drought were analysed using gridded SPI values calculated from gridded rainfall. Temporal analysis of the SPI suggests that the basin suffered severe and extreme drought in the 1970s, 1980s and 2000s. Spatial variation of drought characteristics showed that the occurrence of drought was more in the southern parts; annual drought severity and most intense drought were high in the central and northern parts of the basin. The results of this study can be used for developing drought preparedness plan and formulating mitigation strategies within the basin.

Keywords: Drought severity, GIS, rainfall, return period, SPI