Increasing atmospheric evaporative demand across the Tibetan plateau and implications for surface water resources
Shiqin Xu,
Dennis P. Lettenmaier,
Tim R. McVicar,
Pierre Gentine,
Hylke E. Beck,
Joshua B. Fisher,
Zhongbo Yu,
Ningpeng Dong,
Akash Koppa,
Matthew F. McCabe
Affiliations
Shiqin Xu
Hydrology, Agriculture and Land Observation (HALO) Laboratory, Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia; Climate and Livability Initiative, Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia; Corresponding author
Dennis P. Lettenmaier
Department of Geography, University of California, Los Angeles, Los Angeles, CA, USA; Corresponding author
Tim R. McVicar
CSIRO Environment, Canberra, ACT, Australia; Australian Research Council Centre of Excellence for Climate Extremes, Canberra, ACT, Australia
Pierre Gentine
Department of Earth and Environmental Engineering, Columbia University, New York, NY, USA
Hylke E. Beck
Climate and Livability Initiative, Physical Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
Joshua B. Fisher
Schmid College of Science and Technology, Chapman University, Orange, CA, USA
Zhongbo Yu
National Key Laboratory of Water Disaster Prevention, Hohai University, Nanjing, P.R. China; College of Hydrology and Water Resources, Hohai University, Nanjing, P.R. China
Ningpeng Dong
State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, China Institute of Water Resources and Hydropower Research, Beijing, P.R. China
Akash Koppa
Laboratory of Catchment Hydrology and Geomorphology, School of Architecture, Civil and Environmental Engineering, EPFL Valais Wallis, Sion, Switzerland
Matthew F. McCabe
Hydrology, Agriculture and Land Observation (HALO) Laboratory, Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia; Climate and Livability Initiative, Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
Summary: The Tibetan Plateau, known as the “Asian water tower,” is a hotspot for complex hydroclimatic changes. We reveal that the previously decreasing atmospheric evaporative demand (Eo) trend at the end of the 20th century has reversed over the last two decades. Although both wind stilling and solar dimming have persisted, their effects on Eo rates have been overshadowed by increasing air temperatures and decreasing relative humidity, leading to a net rise in Eo for 1980−2015. Using the empirical “top-down” Budyko approach, we estimate that across seven sub-catchments draining the Tibetan Plateau, a 10% increase in annual-averaged precipitation, assuming all other factors remain constant, would lead to a 15%–19% increase in streamflow. Conversely, a 10% increase in annual-averaged Eo would decrease streamflow by 5%–9%. Our findings provide a deeper understanding of the accelerating hydroclimatic changes and their impact on surface water resources in the Tibetan Plateau.
