Pradip Dalavi, A.N. Mankar, S.B. Wadatkar and Priyanka Sharma
Abstract
Estimation of evapotranspiration and free water surface evaporation from pan evaporation measurements have been increased worldwide. In irrigation scheduling and irrigation system design pan evaporation measurements is critical. In this regard, a number of models for estimation of evaporation have been proposed and developed by several investigators for different locations. In order to assess the adaptability of different methods for estimation of evaporation from free water surfaces in semi-arid areas, this study was carried out. The estimates of evaporation from free water surface obtained by four methods namely Penman combination Model, Priestley-Taylor model, Dalton model, Energy balance model are compared with observed pan values on daily basis. The comparison of daily values indicated that the estimates of evaporation by both Dalton and energy balance model gave good correlation with corrected pan values. Earlier studies conducted had also come up with more or less similar results. It may now be concluded that the both Dalton and energy balance model are reliable approaches for estimation of evaporation from reservoirs and lakes in semi arid region Akola. However, simplicity in using and calculating daily evaporation, the Dalton model is having very much advantage over Energy balance based model.