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Intensification of hydrological drought in California by human water management
Author(s) -
He Xiaogang,
Wada Yoshihide,
Wanders Niko,
Sheffield Justin
Publication year - 2017
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2016gl071665
Subject(s) - san joaquin , environmental science , hydrology (agriculture) , return period , irrigation , drainage basin , structural basin , drainage , water consumption , water resource management , climatology , geography , geology , ecology , flood myth , soil science , paleontology , geotechnical engineering , cartography , archaeology , biology
Abstract We analyze the contribution of human water management to the intensification or mitigation of hydrological drought over California using the PCR‐GLOBWB hydrological model at 0.5° resolution for the period 1979–2014. We demonstrate that including water management in the modeling framework results in more accurate discharge representation. During the severe 2014 drought, water management alleviated the drought deficit by ∼50% in Southern California through reservoir operation during low‐flow periods. However, human water consumption (mostly irrigation) in the Central Valley increased drought duration and deficit by 50% and 50–100%, respectively. Return level analysis indicates that there is more than 50% chance that the probability of occurrence of an extreme 2014 magnitude drought event was at least doubled under the influence of human activities compared to natural variability. This impact is most significant over the San Joaquin Drainage basin with a 50% and 75% likelihood that the return period is more than 3.5 and 1.5 times larger, respectively, because of human activities.