Hydrologic connectivity constrains partitioning of global terrestrial water fluxes

TitleHydrologic connectivity constrains partitioning of global terrestrial water fluxes
Publication TypeJournal Article
Year of Publication2015
AuthorsGood, SP, Noone, D, Bowen, G
JournalScience
Volume349
Issue6244
Pagination175 - 177
Date PublishedOct-07-2015
ISSN0036-8075
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 standard deviation) of evapotranspiration, and 65 ± 26% of evaporation originates from soils and not surface waters. We estimate that 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 through catchments.

URLhttp://www.sciencemag.org/cgi/doi/10.1126/science.aaa5931
DOI10.1126/science.aaa5931
Short TitleScience