IMPLICATIONS OF LAND SUBSIDENCE DUE TO GROUNDWATER OVER-PUMPING: MONITORING METHODOLOGY USING GRACE DATA

Abstract

Groundwater over-pumping is a chief contributor to groundwater quality degradation and land
subsidence. Expecting land subsidence is quite difficult, thus using satellite data to monitor such disaster is
highly promising. This paper presents the use of Gravity Recovery and Climate Experiment data along with
Global Land Data Assimilation System data to monitor and investigate land subsidence resulting from the
impact of groundwater depletion in different regions throughout the world. The trend rates of groundwater
depletion were spatiotemporally estimated to map and detect the occurring and prone regions of land
subsidence. The groundwater storage changes exhibit a declining linear trend during the testing period (2002-
2015) with a rate of 3.4 km3/year at Missouri State in US. Based on the estimated linear tend of groundwater
depletions, the method is validated at Missouri State by some exiting land subsidence such as sinkholes. Then,
the approach is applied for the global and continental scales as example of US. The results also exhibit that the
southern and some in the northern of US are the most prone regions for land subsidence. During the period
2009-2013, there was a great depletions and the results exhibit that mostly the abstractions from the North to
the south of US and especially in the middle. Global estimates of groundwater storage changes also were
conducted which can be used to estimate the groundwater depletion trends at any region throughout the world.
These analyses could be helpful for monitoring and assessment of land subsidence in regions where subsidence
impacts are great.