Socioeconomic Drought Under Growing Population and Changing Climate: A New Index Considering the Resilience of a Regional Water Resources System

Abstract

AbstractSocioeconomic drought occurs when water supply from a regional water resources system cannot meet the water demands. Even if a socioeconomic drought ends, the antecedent water deficit may continue to have impacts for some time, thus influencing the resilience of a regional water resources system. To take this into account, especially under growing population and changing climate, this study develops a new method through integrating a new index, Water Resources System Resilience Index (WRSRI), into socioeconomic drought event identification. The new index represents the percentage of the antecedent water deficit for a socioeconomic drought that can be recovered from the excess water during subsequent periods through analyzing records of a historical drought event. The methodology, implemented on the East River Basin in South China, involves three major steps: (1) calculation of WRSRI value; (2) analysis of key features of identified future socioeconomic drought events, that is, total number, longest duration (LD), and percentage on different drought levels; and (3) sensitivity analysis of WRSRI based on a total of 52 streamflow data sets generated from General Circulation Model outputs and using a macroscale hydrologic model. The results indicate that, for each data set, the total number decreases with an increase in WRSRI but the LD increases; moreover, for most data sets, the LD is less sensitive within the WRSRI range of [0, 0.6]. The outcomes of this study can enhance our capability in more effectively assessing the resilience of a regional water resources system, especially under changing future socioeconomic and environmental conditions.