Scentific Research

The research group of Prof. Juanle Wang, the researcher of the fourth major research field of China-Pakistan Joint Research Centre on Earth Sciences, have achieved significant progress in investigating the consequences of groundwater depletion on surface land in Lahore, Pakistan.

Ensuring sustainable water resource management in the China-Pakistan Economic Corridor is crucial for the safety of energy projects related to hydrological resources. Rising demand for groundwater in urban and agricultural sectors, coupled with unstable groundwater ecosystems, poses threats to regional water and ecological security. Overexploitation of groundwater is not only causing groundwater level (GWL) depletion but also leading to land surface deformation, raising concerns for sustainable development and urban planning in the region. The depletion of groundwater and changes in GWL constitute an alarming situation for sustainable development in the region. Groundwater depletion and change in GWL information refer to the continuous monitoring of time series wells data in the region, which has been consistently monitored throughout the year. Meanwhile to monitor land subsidence in the region, time series Synthetic Aperture Radar (SAR) dataset, to estimation of line of sight (LOS) displacement. Obtaining this information is an important basis for formulating policies for sustainable urban development and regional groundwater resources management.

Focusing on these major issues, Prof. Juanle Wan’s research group used Ps-InSAR techniques and the Mann–Kendall (MK) test combined with remote sensing data, to monitor groundwater depletion and its impact on the surface land in Lahore Pakistan. The high-resolution sentinel-1 SAR dataset was employed for land surface deformation analysis in the region between 2017-2020 combined with climatic parameter of precipitation, and population density from 2003 to 2020, to monitor the impact of groundwater depletion on land subsidence in Lahore Pakistan. Overall, the results of spatial analysis showed significant increases in land subsidence and groundwater depletion in urban areas of Lahore from 2017 to 2020, particularly in the city center. Notably, the annual mean subsidence during this period increased from -27 mm/year to -106 mm/year, indicating an accelerating trend with an average subsidence of -20 mm/year. Furthermore, the Mann–Kendall test indicated a declining trend in (GWL), averaging 0.49 m/year from 2003 to 2020, exacerbating land subsidence due to extensive groundwater extraction for domestic and industrial use. The Climatic parameter of precipitation and population density further reveal an insignificant increasing trend. The research provides an important database and monitoring method for groundwater resource management, protecting against environmental degradation, and promoting regional sustainable urban development in the major cities of Pakistan within the China-Pakistan Corridor.

The relevant research findings, funded by the China–Pakistan Joint Research Centre on Earth Sciences, were recently published online in the journal Remote Sensing.

Link: https:// doi.org/10.3390/rs15225418

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