Journal of Hydrology: Regional Studies (Feb 2023)
Characterization and propagation from meteorological to groundwater drought in different aquifers with multiple timescales
Abstract
Study region: Zhanjiang City District, southwest of Guangdong Province, China, was selected as the case study area owing to its relatively frequent occurrence of droughts and groundwater overexploitation. Study focus: This study presents a useful framework to characterize the propagation from meteorological drought (MD) to groundwater drought (GD) in different aquifers from the perspective of multiple timescales. Two standardized drought indices, i.e., standardized groundwater index and standardized precipitation index with different timescales (1–48 months), were used to examine the propagation time from MD to GD in different aquifers. Three clusters, i.e., natural(P)-, natural+human(P + H)-, and human(H)-induced drought, were considered for revealing the potential driving mechanism of propagation. Four characteristic mechanisms of lag, pooling, lengthening, and attenuation were used to analyze the propagation process from MD to GD, among which the lag characteristic, showing the propagation time, was discussed corresponding to varied clusters. New hydrological insights for the region: Results indicate the following: (1) The propagation time in different aquifers varied; that is, in the shallow aquifer, the average propagation time showed 1 month for the P cluster and 3 months for the P + H cluster, while the propagation time in the middle and deep aquifers were found to be longer than that in the shallow layer though much uncertainty remained for the former. (2) The influences from MD obtained the decreasing order of P > P + H>H. The propagation time of the P + H cluster was longer than that of the P cluster, suggesting the negative influence of human activities. This study can provide additional information for policymakers involved in groundwater management during a drought.
