'American Association for the Advancement of Science (AAAS)'
Abstract
Continental precipitation not routed to the oceans as runoff returns to the atmosphere as evapotranspiration. Partitioning this evapotranspiration flux into interception, transpiration, soil evaporation, and surface water evaporation is difficult using traditional hydrological methods yet critical for understanding the water cycle and linked ecological processes. We combined two large-scale flux-partitioning approaches to quantify evapotranspiration subcomponents and the hydrologic connectivity of bound, plant-available soil waters with more mobile surface waters. Globally, transpiration is 64±13% (mean ±1 s.d.) of evapotranspiration, and 65±26% of evaporation originates from soils and not surface waters. We estimate 38±28% of surface water is derived from the plant-accessed soil water pool. This limited connectivity between soil and surface waters fundamentally structures the physical and biogeochemical interactions of water transiting though catchments.This is the author’s version of the work. It is posted here by permission of the AAAS for personal use, not for redistribution. The definitive version was published in the journal Science on 10 July 2015, Volume 349 number 6244, DOI:10.1126/science.aaa5931. The published article is copyrighted by the American Association for the Advancement of Science and can be found at: http://www.sciencemag.org/journals
