Spatiotemporal heterogeneity and driving mechanisms of water resources carrying capacity for sustainable development of Guangdong Province in China

Sustainable water resources utilization is of great significance for sustainable socioeconomic development. Water resources carrying capacity (WRCC), as an important measurement, plays a vital role in guiding regional water resources management and sustainable utilization. Existing studies on WRCC are abundant, but in-depth studies on the multidimensional evolution of WRCC and its driving mechanism are still lacking. Therefore, taking Guangdong (GD) Province as a case, this study is aimed to propose a systematical WRCC research framework and attempts to explore the spatiotemporal heterogeneity of regional WRCC and reveal its evolutionary driving mechanisms. First, a simplified and effective WRCC index system is constructed through the correlation and contribution rate analysis to remove redundant information. Then, a coupled model consisting of an improved technique for order preference by similarity to ideal solution (TOPSIS) and grey relational analysis model is proposed to accurately evaluate WRCC. Last, the geographically and temporally weighted regression (GTWR) and geographical detector models are introduced to perform the driving analysis of WRCC. Results show that (1) from 2009 to 2020, the WRCCs of GD Province and its 21 cities all show an upward trend with the order of the WRCCs from high to low being northern GD, Pearl River Delta (PRD), eastern GD and western GD. (2) The main driving forces of WRCC in GD gradually shift from social and economic development to economic and ecological development. (3) Municipal sewage treatment rate, proportion of the tertiary industry and GDP per capita are the key driving factors of the GD WRCC. This study provides a new perspective for regional WRCC improvement and is greatly helpful to make differentiated management measures.