Assessing the spatial characteristics of drought hazard in the state of Rajasthan

The frequency of extreme dry events, such as drought, is on the rise due to recent exacerbated warming, significantly impacting various socio-economic sectors, especially in arid regions like the Indian state of Rajasthan. In this study, using the Standardized Precipitation Index (SPI), we examined meteorological drought characteristics in Rajasthan to identify three categories of drought events (mild, moderate, and severe) at multi-temporal scales (i.e., 3-month, 6-month, and 12-month) based on monthly rainfall data from 1988 to 2021. Our findings indicate that milder droughts are more frequent in Rajasthan than moderate and severe droughts. Mild and moderate droughts are common during April – June, whereas severe drought events predominantly occur during July – September. Drought hazard maps produced at different temporal scales, by combining the frequency, intensity, and duration of drought events, indicate that the northern and northwestern regions are the most drought-prone areas within the state. Analysis of rainfall and drought trends based on the Mann-Kendall (MK) test suggests that out of the 165 stations examined, 26 stations exhibit a significantly increasing trend in mean annual rainfall. Conversely, only 2 stations demonstrated a significant decreasing trend in rainfall. In response to the increasing rainfall, drought events are found to decrease over the study period even at a shorter temporal scale (i.e., 3month-SPI) at most of the stations. Policymakers and stakeholders could benefit from the long-term drought hazard map in identifying drought-prone regions and formulating policies and programs to promote water conservation and enhance drought preparedness in the state.