Spatiotemporal Drought Analysis

Abstract

Droughts are characterized as abnormal hydrological conditions associated with a water deficit extending over long time durations (months to seasons) and large geographical areas. The identification and characterization of droughts are vital for regional water resources management. This chapter presents a spatiotemporal assessment of drought severity by constructing severity–area–frequency (SAF) and severity–duration–frequency (SDF) curves for a drought-affected region in India. A review of various drought indices available for the estimation of meteorological droughts is presented in this chapter along with a detailed description of the construction of SAF and SDF curves using the Standardized Precipitation Index (SPI). The application of spatiotemporal drought analysis is demonstrated by using grid-based fine resolution rainfall data (0.25° × 0.25°) for western India. The SAF and SDF curves are constructed for the region for different drought durations and the temporal variations in their characteristics are also evaluated across three equal periods, viz., initial period (1901–1938), mid-period (1939–1976), and recent period (1977–2015). Short-term droughts (SPI-3) are found to be more frequent in the recent period compared to the other periods. On the other hand, the long-term drought (SPI-12) shows higher (lower) severity across most parts of the basin for lower (higher) return periods in the recent period as compared to the initial period and mid-period. © 2023 CRC Press.