Heterogeneity and imbalance of water supply and demand under climate change and human activities in the Beibu Gulf region, China

The Beibu Gulf area (BG), China. The purpose of this study is to assess the impact of climate change and human activities on the water supply-demand (WSD) in the BG, and to quantify the driving effects and contributions of natural and socio-economic factors to water resources changes in different scenarios. The study indicated that the water yield (WY) gradually decreased from southeast to northwest from 2000 to 2020, but this trend is projected to reverse, with WY increasing from south to north in the future. Climate change is the primary driver of spatial heterogeneity in WY, contributing 88.86–112.42 %, and also influencing the effect of land use on water supply services. However, human activities have a more significant impact on the WSD ratio, with q-value ranging between 20.83 % and 66.37 %. Despite relatively abundant water resources in the BG, approximately one-third of the area faces water scarcity or severe shortages due to uneven resource distribution and varying levels of regional economic development. These findings provide a scientific basis for regional water resource management and sustainable development. • Climate change is the key factor affecting water resource quantity and distribution. • A mismatch between water supply-demand persists in the Beibu Gulf from 2000 to 2060. • Natural recharge fails to meet water supply demands in urban core areas.