Groundwater drought characteristics and its dynamic response to meteorological drought in Qingdao plain area

Abstract

[Objective] To explore the spatiotemporal characteristics of groundwater drought and its dynamic response to meteorological drought in Qingdao plain areas, [Methods] the standardized groundwater index(SGI) and standardized precipitation index(SPI) at the multi-scale were calculated using monthly groundwater level data from 20 monitoring wells and monthly precipitation data from Pingdu Station from 2000 to 2020. The evolution and trend characteristics of groundwater drought and meteorological drought were analyzed, and Kendall's rank correlation coefficient was used to quantitatively identify the dynamic response relationship between groundwater drought and meteorological drought. [Results] The result indicate that both groundwater and precipitation in the study area tend to become wet first and then dry, and the occurrence time of groundwater drought is later than that of meteorological drought. The response time of groundwater drought to meteorological drought is 30~56 months, and the overall response degree is strong. The maximum correlation coefficients between SGI and SPI-n(n=1, 2,… 48) in spring, summer, autumn, and winter were 0.42, 0.84, 0.65, and 0.57, respectively. The response degree of groundwater drought to meteorological drought was significantly stronger in summer and autumn than in spring and winter. The correlation coefficient between SGI and SPI-n in the southwest is significantly lower than in other regions. [Conclusion] The result reveal that there is spatiotemporal heterogeneity in groundwater drought and its response to meteorological drought in the study area, influenced by factors such as precipitation, lithology of the aquifer, and groundwater exploitation. The propagation from meteorological drought to groundwater drought is a slowly evolving implicit process. Understanding the spatiotemporal response relationship between groundwater drought and meteorological drought can provide reference for the early warning and prevention of groundwater drought.

Keywords

groundwater drought / meteorological drought / standardized groundwater index / standardized precipitation index / dynamic response / water resources / spatiotemporal changes