Divergent Trends of Water Storage Observed via Gravity Satellite across Distinct Areas in China

Panxing He,Xiaoliang Ma,Yifei Liu,Pei Zhao,Zhiming Han,Zongjiu Sun,Jun Ma

doi:10.3390/w12102862

Abstract

Knowledge of the spatiotemporal variations of terrestrial water storage (TWS) is critical for the sustainable management of water resources in China. However, this knowledge has not been quantified and compared for the different climate types and underlying surface characteristics. Here, we present observational evidence for the spatiotemporal dynamics of water storage based on the products from the Gravity Recovery and Climate Experiment (GRACE) and the Global Land Data Assimilation System (GLDAS) in China over 2003–2016. Our results were the following: (1) gravity satellite dataset showed divergent trends of TWS across distinct areas due to human factors and climate factors. The overall changing trend of water storage is that the north experiences a loss of water and the south gains in water, which aggravates the uneven spatial distribution of water resources in China. (2) In the eastern monsoon area, the depletion of water storage in North China (NC) was found to be mostly due to anthropogenic disturbance through groundwater pumping in plain areas. However, precipitation was shown to be a key driver for the increase of water storage in South China (SC). Increasing precipitation in SC was linked to atmospheric circulation enhancement and Pacific Ocean warming, meaning an unrecognized teleconnection between circulation anomalies and water storage. (3) At high altitudes in the west, the change of water storage was affected by the melting of ice and snow due to the rising temperatures, yet the topography determines the trend of water storage. We found that the mountainous terrain led to the loss of water storage in Tianshan Mountain (TSM), while the closed basin topography gathered the melted water in the interior of the Tibetan Plateau (ITP). This study highlights the impacts of the local climate and topography on terrestrial water storage, and has reference value for the government and the public to address the crisis of water resources in China.

Highlights

Water shortage is undoubtedly a global crisis [1]
Linear regression and correlation analysis jointly proved that the trends of terrestrial water storage (TWS) and soil moisture storage (SMS) were consistent in space at the pixel, province, and basin scale
Compared with Global Land Data Assimilation System (GLDAS) soil water storage, we propose that the equivalent water height from gravity satellite is a better indicator to describe large-scale water storage

Summary

Introduction

Water shortage is undoubtedly a global crisis [1]. Under the background of global warming, the intensification of water circulation will lead to the imbalance of TWS among regions [3], which threaten human production and domestic water supply. Urbanization and population explosion lead to the rapid increase of irrigation water, domestic water, and manufacturing water demand, which aggravates the shortage of water resources. The traditional way to estimate the TWS is the water balance equation (that is precipitation–evapotranspiration–runoff) at a small basin scale. This is extremely challenging on a national scale [5]. The data collected by the stations have observation deviation, which is affected by the surrounding environment of the stations.

Methods

Results

Discussion

Conclusion