Cao Y, Nan Z, Cheng G, Zhang L. Hydrological variability in the arid lands of northwest China during 2002-2013. Advances in Meteorology. 2018, 2018(1502472): 1-13. DOI:10.1155/2018/1502472.
The arid region of Northwest China (ANC) has a distinct and fragile inland water cycle. This study examined the hydrological variations in ANC and its three subregions from August 2002 to December 2013 by integrating terrestrial water storage (TWS) anomaly data derived from the Gravity Recovery and Climate Experiment (GRACE) satellite, soil moisture data modeled by the Global Land Data Assimilation System, and passive microwave snow water equivalent data. The results show that the TWS in ANC increased at a rate of 1.7mm/a over the past decade, which consisted of an increasing trend of precipitation (0.12mm/a). Spatially, in the northern ANC, TWS exhibited a significant decreasing trend of −3.64 mm/a ( < 0.05) as a result of reduced rainfall, increased glacial meltwater draining away from the mountains, and intensified human activities. The TWS in southern and eastern ANC increased at a rate of 2.14 ( = 0.10) and 1.63 ( < 0.01)mm/a, respectively. In addition to increasing precipitation and temperature, decreasing potential evapotranspiration in Southern Xinjiang and expanding human activities in Hexi-Alashan together led to an overall increase in TWS. Increased glacier meltwater and permafrost degradation in response to climate warming may also affect the regional TWS balance. The variations in soil moisture, groundwater, and surface water accounted for the majority of the TWS anomalies in southern and easternANC.The proposed remote sensing approach combiningmultiple data sources proved applicable and useful to understand the spatiotemporal characteristics of hydrological variability in a large area of arid land without the need for field observations.