Climate change and water storage variability over an arid endorheic region

•TWS variations in the TRB and underlying causes are investigated using GRACE.•An excess of precipitation over ET plus runoff contributes to an increase of TWS.•Increasing snowmelt results in an increase of subsurface water.

SummaryTerrestrial Water Storage (TWS) plays an important role in regional climate and water resources management, especially in arid regions under global change context. However, serious lack of in-situ measurements in remote alpine mountains is hindering our current understanding of regional TWS change in the Tarim River Basin (TRB), a large and typical arid endorheic area in Northwest China of Central Asia. To solve the problem, four different hydrology products from the Gravity Recovery and Climate Experiment (GRACE) satellite, model simulations from Global Land Data Assimilation System (GLDAS) in conjunction with in-situ measurements, are utilized to investigate patterns and underlying causes of TWS and its component changes. An excess of precipitation over evapotranspiration (ET) plus runoff contributes to an increase of TWS. The phase of Total Soil Moisture (TSM) lags that of Snow Water Equivalent (SWE), indicating a recharge from snowmelt to TSM. Increasing TWS together with decreasing SWE resulted in an increase of subsurface water. Our results are of great value to amend basin-wide water management and conservation strategies for the similar arid regions considering climate change.