Drought vulnerability assessment in Jalna using drought indices

Abstract

Drought is a temporary and recurring hydro-meteorological event, which originates from the lack of precipitation, high temperature, and high evaporation over extended period of time. It is a normal part of any climate and, perhaps the most complex natural hazard, because it develops slowly, it is difficult to detect and has many facets in any single region. Drought preparedness and mitigation depends upon timely information on drought onset, development in time and spatial extent. This information may be obtained through continuous drought monitoring, which is normally performed using drought indices. This project work describes drought assessment, using two different drought indices, SPI (Standardized Precipitation Index) and RAI (Rainfall Anomaly Index). The Marathwada region of Maharashtra was chosen as the study area and this region is characterized as a ‘frequently drought prone area’, where drought can be expected every 6 to 10 years. A comparison of RAI and SPI values were done for determination of drought severity and temporal extension of drought for planning of mitigation measures for farmers. Using the SPI and RAI as indicators of drought severity from 1901-2002, the characteristics of drought were examined. The monthly rainfall data for the period (2012-2016) was also analyzed and the severity of drought was evaluated as a check with the historical data. The maximum annual SPI was -2.61 in the year 1920, similarly the RAI values also showed the same results which was -4.748 indicating the extreme drought conditions in the study area. The monthly SPI values were also compared with RAI+ and RAI- values for the period under observation. It was observed that the RAI- is highly correlated with SPI for determining the characteristics of droughts in the study area. The overall outcome of this study demonstrates that extreme and severe droughts were experienced in the years 1920, 1972 and 1911, 1912, 1918, 2000, 2001 across the study area leading to unfavourable results on agricultural practices and water resources in the area.