The estimation of evaporation from U.S. Weather Bureau Class A pans.
| Main Author: | |
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| Other Authors: | , , , |
| Format: | Thesis Book |
| Language: | English |
| Published: |
[College Station, Tex.],
1965.
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| Subjects: | |
| Online Access: | Link to OAKTrust Copy Link to ProQuest copy |
| Abstract: | Several statistical procedures have been developed to meet the requirements of those seeking estimates of the amount and rate of monthly evaporation from U. S. Weather Bureau Class A pans. Records of monthly evaporation from Class A pans and monthly mean temperatures for 105 stations in 12 southwestern states were used to develop the statistical relationships. A multiple regression equation of mean monthly evaporation on the mean temperature for two consecutive months was found to be quite reliable. Harmonic analysis of the time variation of mean monthly evaporation and mean monthly temperature (the "annual waves") has demonstrated that the first harmonic of a Fourier series can be used to represent the annual variation with considerable accuracy. The annual waves of temperature and evaporation are observed to be out of phase by an amount which is related to the amount of moisture in the atmosphere. Maps of the parameters of the harmonic and regression analyses are presented for the 12 southwestern states. Values interpolated from the maps can be used to estimate Class A pan evaporation at sites not serviced by a pan. Statistical and physical reasoning is presented which accounts for the success of the multiple regression and Fourier series representations for estimating values of monthly mean evaporation. It is demonstrated further that knowledge of the difference in phase and amplitude of two annual waves can be used to estimate values of one in terms of the other. |
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| Physical Description: | 144 leaves illustrations |