Quantification of sector-specific groundwater withdrawals considering water diversion projects in the Hebei Province, China

Abstract

Study areaHebei Province, China Study focusAccurate assessment of sector-specific groundwater withdrawals (GWW) is fundamental for targeted groundwater management policies, particularly in regions suffering from severe groundwater over-extraction. Due to the lack of statistical data and the coarse resolution of water supply patterns and GWW, previous studies couldn’t well quantify the GWW where the impact of inter-basin water diversion projects was also neglected. Here we proposed a methodology to simulate sectoral GWW based on flux balance in consideration of the influence of inter-basin water diversion projects. New hydrological insights for the study regionA case study in Hebei Province, where groundwater is severely over extracted, was used to validate our methodology. Our results showed that the gridded GWW calculations are well aligned with the statistical data from the Hebei Water Resources Bulletin (WRB) at both provincial and municipal levels, with correlation coefficients (R) above 0.9 and normalized root mean squared errors (NRMSE) below 0.1. County-level GWW estimates also match with data from the Department of Water Resources of Hebei Province for 2013 and 2018, with NRMSE around 0.2. Piecewise Linear Regression (PLR) analysis of sectoral GWW further reveals that GWW is quickly declined when water diversion projects or policies are implemented. Together our findings underscore a significant role of water resource engineering and policies in alleviating groundwater over-extraction.