Origins and variability of extreme precipitation in the Santa Ynez River Basin of Southern California
| Autor: | F. M. Ralph, E. Boldt, Nina S. Oakley, Forest Cannon, John Dumas |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
location.dated_location
geography geography.geographical_feature_category 010504 meteorology & atmospheric sciences lcsh:QE1-996.5 Santa Ynez Extreme events Drainage basin Structural basin 010502 geochemistry & geophysics 01 natural sciences Watershed scale lcsh:Geology location El Niño Southern Oscillation Earth and Planetary Sciences (miscellaneous) Environmental science Precipitation Physical geography lcsh:GB3-5030 Weather patterns lcsh:Physical geography 0105 earth and related environmental sciences Water Science and Technology |
| Zdroj: | Journal of Hydrology: Regional Studies, Vol 19, Iss, Pp 164-176 (2018) |
| ISSN: | 2214-5818 |
| Popis: | Study region: Santa Ynez River Basin, Santa Barbara County, California. Study focus: Lake Cachuma, a reservoir on the Santa Ynez River, provides water for over 280,000 residents and agricultural lands of Santa Barbara County, California. This area experiences high inter-annual precipitation variability, which we hypothesize is driven by the presence or absence of a few large precipitation events each year. We use daily precipitation observations from 1965 to 2017 to identify extreme precipitation events, defined as those exceeding the 90th percentile. We examine the role of these events, their associated synoptic patterns, and the El Niño Southern Oscillation (ENSO) in driving inter-annual precipitation variability in this basin. New hydrological insights for the region: On average, a wet year features three or more extreme events, a normal year 1–2 events, and a dry year 0–1 events. We identify four distinct synoptic-scale weather patterns associated with extreme events and find that 74% of events are associated with atmospheric rivers. El Niño years tend to have a greater number of extreme events, though this relationship is not dependable. The reliance on just a few extreme precipitation events and diversity among these events highlights the challenges of seasonal prediction and resource management in this area. This novel approach to defining variability on a watershed scale can support ecological, geological, and hydrological studies as well as regional water resource management. Keywords: Lake Cachuma, Southern California, Precipitation extremes, Precipitation variability, Drought, Water resources |
| Databáze: | OpenAIRE |
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