27 NOV 2025 (THU) 15:05 - 15:35

Tracking the sources of terrestrial water deficit during drought development from a water balance perspective

Mr LIU Rutong  

( Supervisor: Prof Laibao Liu )

Abstract:

Terrestrial Water Storage (TWS) constitutes the largest accessible freshwater bank on earth and serves as a critical buffer against hydrological extremes. TWS deficits integrate the cumulative impacts of precipitation deficits and elevated evapotranspiration, providing a more comprehensive and persistent indicator of drought severity than conventional meteorological or soil-moisture-based indices. This study tracks the sources and evolution of TWS deficits during drought development from a water-balance perspective using Gravity Recovery and Climate Experiment (GRACE) and GRACE-FO observations. We quantify the effect of evapotranspiration (ET) anomalies to TWS drought and assess their relative importance compared to precipitation anomalies, thereby elucidating the role of atmospheric water demand in drought development. Finally, we examine global patterns of ET-drought interactions across varying levels of water constraint, highlighting contrasting ET responses to TWS deficits in water-limited (dryland) and energy-limited (humid) environments.