Separating the Precipitation- and Non-Precipitation- Driven Water Storage Trends in China

Terrestrial water storage (TWS) is a critical component for sustainable societal development and ecosystem cycles. The Gravity Recovery and Climate Experiment satellites have tracked changes in global TWS under the combined effects of various factors with unprecedented accuracy since 2002. In this study, we separate the trends in TWS driven by precipitation and non-precipitation factors for the Chinese mainland from 2003 to 2016 based on the statistical reconstruction method and linear regression and analyze the driving mechanisms combining with multi-source data. The results show that: (a) during the study period, TWS shows different degrees of increase in most of the Yangtze River basin, the northern part of the Tibetan Plateau, and part of the Heilongjiang Province, while TWS shows a significant decrease in the Tien Shan Mountains, the southeastern part of the Tibetan Plateau, and the North China Plain; (b) precipitation is one of the dominant factors leading to the rise of TWS, and the construction of reservoirs and dams also contributes. In contrast, anthropogenic activities (agricultural irrigation, industrial water use, etc.) and accelerated glacial melting due to global warming are the dominant factors in the decline of water storage; (c) the contribution of long-term precipitation change to water storage is significantly larger in the northern China region (north of the 800 mm isopleth). This study provides a feasible method for quantifying the contribution of precipitation and non-precipitation factors to TWS, which is meaningful for understanding the impact of climate change and anthropogenic factors on water resources.

Automated summary

This study analyzes the trends in terrestrial water storage (TWS) driven by precipitation and non-precipitation factors in the Chinese mainland from 2003 to 2016. The results show that TWS has increased in the Yangtze River basin, the northern part of the Tibetan Plateau, and part of Heilongjiang Province, while it has decreased in the Tien Shan Mountains, the southeastern part of the Tibetan Plateau, and the North China Plain. Precipitation and reservoir construction contribute to the rise of TWS, while anthropogenic activities and glacial melting due to global warming contribute to the decline. Long-term precipitation change has a significant impact on water storage in northern China.