Monitoring regional groundwater reserve by gravity satellite and its response to the"July 20"catastrophic rainstorm in Zhengzhou
Pan Yun
Chen Wenze
Zhang Chong
Abstract：In the context of frequent extreme precipitation events,understanding the response of depleted aquifers to rainfall events has become a new challenge for groundwater resource management under the influence of climate change and human activities.Taking the catastrophic rainstorm in Zhengzhou on July 20,2021,as an example,this study leverages the advantages of gravity satellites in monitoring large-scale mass changes to reveal the impact of extreme rainfall on the groundwater reserve changes in regional aquifer systems under long-term over-extraction.The study found that the GRACE gravity satellite could clearly capture the increase in groundwater reserves caused by this rainfall event,with a correlation coefficient of 0.84 between gravity satellite data and well observations.The rainfall event resulted in a cumulative increase of 13.278 billion cubic meters of groundwater reserves in the study area(379 100 km²)as of the end of November 2021.The groundwater recharge coefficient(the ratio of groundwater recharge to rainfall)for this event reached 0.36,significantly higher than the average recharge coefficient of 0.19 for historical rainfall events,indicating the unique recharge capacity of heavy rainfall on regional aquifers.This study shows that extreme rainfall has a significant recharge effect on depleted aquifers,and gravity satellites have potential in assessing the impact of extreme rainfall events on regional groundwater reserve changes.
Keywords：gravity satellitegroundwater reserve changesextreme rainfallgroundwater rechargeZhengzhou rainstorm
Publication Date：2024-06-12
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：7( 45-51 )