| Abstract: | In the Central Valley, Calif., where 57% of the 20,000 square miles of land is irrigated, ground-water recharge from agricultural lands is an important input to digital simulation models of ground-water flow. Several methods of calculating recharge were explored for the Central Valley Aquifer Project and a simplified water budget was designed where net recharge (recharge minus pumpage) equals net surface water diverted minus evapotranspiration of applied water (ETAW). This equation eliminates the need to determine pumpage from the water-table aquifer, assuming that the time lag for infiltration is not longer than the time intervals of interest for modeling. This study evaluates only the evapotranspiration of applied water. Future reports will describe the other components of the water budget. ETAW was calculated by summing the products of ETAW coefficients and respective crop areas for each 7 1/2-minute quadrangle area in the valley, for each of three land-use surveys between 1957 and 1978. In 1975 total ETAW was 15.2 million acre-feet, a 43% increase since 1959. The largest increases were in the south, especially Kern County, which had a sixfold increase, which was caused by the import of surface water in the California Aqueduct. (USGS) |
| Genre: | USGS Numbered Series |
| ProdID: | 30503 |
| Citation Author: | Williamson, Alex K. |
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| Citation Language: | ENGLISH |
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| Citation Phsyical Description: | iv, 56 p. :ill., maps ;28 cm. |
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| Citation Publisher: | U.S. Geological Survey, Water Resources Division, |
| Citation Series: | Water-Resources Investigations Report |
| Citation Series Code: | WRI |
| Citation Series Number: | 81-45 |
| Citation Search Results Text: | Evapotranspiration of applied water, Central Valley, California, 1957-78; 1982; WRI; 81-45; Williamson, Alex K. |
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| Citation Year: | 1982 |
| Type: | citation/reference |
| Text: | Evapotranspiration of applied water, Central Valley, California, 1957-78; 1982; WRI; 81-45; Williamson, Alex K. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/usgs_thumb.jpg |
| Date Other: | Sat, 1 Jan 1994 00:00 -0600 |
| Publisher: | U.S. Geological Survey, Water Resources Division, |
