Analysis of meteorological elements as separates factors affecting class a pan evaporation.

Date

1990

Abstract

This study evaluated different meteorological variables as single, multiple and interactive factors influencing class A pan evaporation. A primary concern was the separation of the integrated effect of these meteorological elements into individual contributing components. Finally, the study attempted to establish the best daily empirical predictive models under Los Baños conditions. Meteorological elements namely: air temperature, relative humidity, total global radiation, sunshine hours, and wind run at one meter above ground were found to significantly affect pan evaporation rates as single-acting factors at the 1% level of significance. Using linear correlation analysis, solar radiation had the highest correlation with pan evaporation for both wet and dry season (r² = 0.9238 and 0.9726 respectively). On the other hand, wind as a single factor had the least correlation with pan evaporation for both seasons. The variability in the dependent variable was best explained by the five-factor variables combination. Partial correlation analysis revealed that air temperature and wind run at one meter above ground are the major significant influencing factors on class A pan evaporation. Air temperature and total global radiation appeared to most significantly affect evaporation during the dry season. Finally, the established daily empirical predictive model for estimating USWB class A pan evaporation under Los Baños conditions can be written as follows: EPA = 0.23548 Ta - 0.05174 RH + 0.00772 SR + 14260 SH + 0.32125 W - 1.99239 (Dry Season, R² = 0.9628) EPA = 0.38519 Ta + 0.00621 SR + 0.19562 SH + 0.35184 W - 10.29043 (Wet Season, R² = 0.9180) The disaggregation of the joint effect of meteorological factors on pan evaporation into individual contributing factors yielded the following results: 1) during the dry season, air temperature accounted for 53.4% of the total daily pan evaporation, followed in decreasing order by total global radiation, wind percent relatively humidity and sunshine hour at 18.93%, 15.55%, 4.20% and 4.13% of the total, respectively: 2) during wet season, air temperature contributed 29.13% of total evaporation followed in decreasing order by wind, total global radiation, sunshine hour and relative humidity at 26.53%, 18.03%, 17.88% and 0.25%, respectively.

Document Type

Master Thesis

Language

English

LC Subject

Meteorology, Evaporation (Meteorology)

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

LG 995 1990 A38 T84

This document is currently not available here.

Share

COinS