Monitoring Groundwater Withdrawal and Potential Land Subsidence in The Limpopo River Basin, Mozambique with Remote Sensing
Abstract
In various regions around the world (e.g. the Central Valley of California, the North China Plain, and Mexico City), excessive groundwater extraction has resulted in aquifer depletion and land subsidence. Along with damage to infrastructure, land subsidence can be especially devastating to coastal regions where rising sea levels can submerge coastlines and saltwater can intrude into important freshwater sources. Groundwater availability and subsidence have historically been monitored using networks of boreholes and GPS stations. In southern Mozambique, groundwater extraction is insufficiently monitored, and the aquifer is unconsolidated, sedimentary; furthermore, increased demand for freshwater during the dry season could make this region susceptible to depletion and subsidence. Such effects would be devastating to those residing in the region, as 60% of the countrys population relies on groundwater for domestic use and agriculture according to the Census of 2007. Changes in groundwater storage in southern Mozambique were monitored using NASAs Gravity Recovery and Climate Experiment (GRACE) satellite. To assess the potential effects of groundwater withdrawal, differential interferometry from ESAs Sentinel-1 Synthetic Aperture Radar was used to monitor ground deformation over three major coastal cities in Mozambique: Maputo, Xai Xai and Inhambane. This represents a novel method to monitor groundwater availability with remote sensing in southern Mozambique - an approach which may prove to be useful for future water management decisions in a country where in situ monitoring is limited.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2021
- Bibcode:
- 2021AGUFM.H31F..07Z