SPATIAL VARIABILITY OF PRECIPITATION IN THE SAN DIMAS EXPERIMENTAL FOREST AND ITS EFFECT ON SIMULATED STREAMFLOW
| dc.contributor.author | Phanartzis, Christos Apostolou,1936- | |
| dc.date.accessioned | 2016-09-13T22:09:33Z | |
| dc.date.available | 2016-09-13T22:09:33Z | |
| dc.date.issued | 1972-06 | |
| dc.identifier.uri | http://hdl.handle.net/10150/620121 | |
| dc.description.abstract | The effect of altitude on individual storm precipitation in some of the San Dimas experimental watersheds is investigated. It is found that there is a well- defined increase of storm precipitation with altitude for storms greater than one inch. This increase is a linear function of storm depth. Using 41 storms of different magnitudes, a precipitation -altitude relationship is derived for a small area in the San Dimas Experimental Forest. The regionalization of this relationship and its transferability are tested by analyzing differences (errors) between computed and observed storm precipitation values in each case. In testing the regionalization of the precipitation- altitude relationship by computing mean areal storm precipitation over a larger area the standard error of estimate is around 11 percent. In transfering the same relationship the results are not as good and give a standard error of 16 percent. For individual points, however, the error is much higher. A rainfall- runoff model is used as a tool for evaluating the effect of precipitation errors, on simulated streamflow, in a watershed of 4.5 square miles. For annual flows, errors range between 3.4 and 12.3 percent while errors in simulated monthly flows are as high as 22 percent. It is also evident that there is a strong dependence of the error magnitude on the state (wet, dry, etc.) of the preceding year or months, whichever is applicable. An error propagation is observed as a result of consistently over -estimating the precipitation input to the model. This evaluation is more of a qualitative nature and the values of error given should be viewed in this sense. | |
| dc.description.sponsorship | Funds for partial support of this thesis came from the project, "Decision- Theoretic Aspects of Model Building, Use and Validation in Hydrology and Water Resources," sponsored by the Office of Water Resources Research, U.S. Department of the Interior. | en |
| dc.language.iso | en_US | en |
| dc.publisher | Department of Hydrology and Water Resources, University of Arizona (Tucson, AZ) | en |
| dc.relation.ispartofseries | Technical Reports on Hydrology and Water Resources, No. 11 | en |
| dc.rights | Copyright © Arizona Board of Regents | en |
| dc.source | Provided by the Department of Hydrology and Water Resources. | en |
| dc.subject | Rain and rainfall -- California -- San Dimas Experimental Forest | en |
| dc.subject | Precipitation (Meteorology) -- Measurement. | en |
| dc.subject | Stream measurements -- California -- San Dimas Experimental Forest. | en |
| dc.title | SPATIAL VARIABILITY OF PRECIPITATION IN THE SAN DIMAS EXPERIMENTAL FOREST AND ITS EFFECT ON SIMULATED STREAMFLOW | en_US |
| dc.type | text | en |
| dc.type | Technical Report | en |
| dc.contributor.department | Department of Hydrology & Water Resources, The University of Arizona | en |
| dc.description.collectioninformation | This title from the Hydrology & Water Resources Technical Reports collection is made available by the Department of Hydrology & Atmospheric Sciences and the University Libraries, University of Arizona. If you have questions about titles in this collection, please contact repository@u.library.arizona.edu. | en |
| refterms.dateFOA | 2018-09-11T14:47:38Z | |
| html.description.abstract | The effect of altitude on individual storm precipitation in some of the San Dimas experimental watersheds is investigated. It is found that there is a well- defined increase of storm precipitation with altitude for storms greater than one inch. This increase is a linear function of storm depth. Using 41 storms of different magnitudes, a precipitation -altitude relationship is derived for a small area in the San Dimas Experimental Forest. The regionalization of this relationship and its transferability are tested by analyzing differences (errors) between computed and observed storm precipitation values in each case. In testing the regionalization of the precipitation- altitude relationship by computing mean areal storm precipitation over a larger area the standard error of estimate is around 11 percent. In transfering the same relationship the results are not as good and give a standard error of 16 percent. For individual points, however, the error is much higher. A rainfall- runoff model is used as a tool for evaluating the effect of precipitation errors, on simulated streamflow, in a watershed of 4.5 square miles. For annual flows, errors range between 3.4 and 12.3 percent while errors in simulated monthly flows are as high as 22 percent. It is also evident that there is a strong dependence of the error magnitude on the state (wet, dry, etc.) of the preceding year or months, whichever is applicable. An error propagation is observed as a result of consistently over -estimating the precipitation input to the model. This evaluation is more of a qualitative nature and the values of error given should be viewed in this sense. |
