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.
| Identifer | oai:union.ndltd.org:arizona.edu/oai:arizona.openrepository.com:10150/620121 |
| Date | 06 1900 |
| Creators | Phanartzis, Christos Apostolou |
| Contributors | Department of Hydrology & Water Resources, The University of Arizona |
| Publisher | Department of Hydrology and Water Resources, University of Arizona (Tucson, AZ) |
| Source Sets | University of Arizona |
| Language | en_US |
| Detected Language | English |
| Type | text, Technical Report |
| Source | Provided by the Department of Hydrology and Water Resources. |
| Rights | Copyright © Arizona Board of Regents |
| Relation | Technical Reports on Hydrology and Water Resources, No. 11 |
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