Spatio-temporal Variation Analysis of Water Resources in the Pearl River Region Based on Hydrological Variation Diagnosis System

Based on the results of the third national water resources survey and evaluation, the hydrological variation diagnosis system was used to systematically diagnose the spatio-temporal variation of water resources in the Pearl River Region, and the driving force of variation was analyzed. The results show that the annual average surface water resources in the Pearl River Region show a stable trend in terms of time series evolution, and there is no significant variation. In terms of spatial distribution, the surface water resources in the three secondary regions of the Pearl River Region, namely Nanbeipan River Region, Hongliu River Region, and Yujiang River Region show a variation in jump decline, a variation in jump rise, and a weak variation in jump rise in 2001, 1992, and 1965 respectively. The comprehensive attribution analysis shows that climate factors are the main factors of regional water resources variation. The decreasing variation in the Nanbeipan River Region, is mainly attributed to the phased reduction of the total amount of decreasing water under the drought background in the southwest, while the increasing variation in the Hongliu River Region and the Yujiang River Region, corresponds to the increasing frequency and intensity of rainstorm and flood after the 1990s and the frequent occurrence of extreme precipitation events after the 1960s, respectively. The change in underlying surface conditions plays a certain role in promoting the variation process in Hongliu River and Yujiang River Regions. The research results can provide important support and basis for water resources management, decision-making, development, and utilization in the Pearl River Region.