https://pure.iiasa.ac.at/id/eprint/14339 2021-08-27T17:28:29Z info:eu-repo/semantics/descriptiveMetadata https://pure.iiasa.ac.at/id/eprint/14339/ Intensification of hydrological drought in California by human water management He, X. Wada, Y. Wanders, N. Sheffield, J. We analyze the contribution of human water management to the intensification and mitigation of hydrological drought over California using the PCR-GLOBWB hydrological model for the period 1979-2014. We demonstrate that considering water management 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. American Geophysical Union 2017-02-28 Article PeerReviewed text en cc_by_nd https://pure.iiasa.ac.at/id/eprint/14339/1/grl55488.pdf He, X., Wada, Y. <https://pure.iiasa.ac.at/view/iiasa/2601.html> ORCID: https://orcid.org/0000-0003-4770-2539 <https://orcid.org/0000-0003-4770-2539>, Wanders, N., & Sheffield, J. (2017). Intensification of hydrological drought in California by human water management. Geophysical Research Letters 24 (4) 1777-1785. 10.1002/2016GL071665 <https://doi.org/10.1002/2016GL071665>. 10.1002/2016GL071665 10.1002/2016GL071665 10.1002/2016GL071665 info:eu-repo/semantics/objectFile info:eu-repo/semantics/humanStartPage