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Date:2019-03-12

Indexed by:Journal Article

Date of Publication:2016-11-01

Journal:WATER RESOURCES RESEARCH

Included Journals:Scopus、EI、SCIE

Volume:52

Issue:11

Page Number:9036-9045

ISSN:0043-1397

Abstract:In this paper, we test the hypothesis that natural catchments utilize hedging strategy for evapotranspiration and water storage carryover with uncertain future precipitation. The hedging strategy for evapotranspiration in catchments under different levels of water availability is analytically derived with marginal utility principle. It is found that there exists hedging between evapotranspiration for present and future only with a portion of water availability. Observation data sets of 160 catchments in the United States covering the period from 1983 to 2003 demonstrate the existence of hedging in catchment hydrology and validate the proposed hedging strategy. We also find that more water is allocated to carryover storage for hedging against the future evapotranspiration deficit in the catchments with larger aridity indexes or with larger variability in future precipitation, i.e., long-term climate and precipitation variability control the degree of hedging.