EVALUATION OF EVAPOTRANSPIRATION

Abstract

In designation water use by crops, evaporation and transpiration are combined in one term called evapo-transpiration (ET), as it is difficult to separate those two losses in crop field. Evaporation and transpiration are simultaneously and it is not easy to distinguish between the two processes. Evapotranspiration is a complex phenomenon it depends on various factors as pressure, wind speed, temperature, humidity, solar radiation, vapor etc. Evapotranspiration can be measured by different five principles method viz. lysimeter method, Hargreaves class ‘A’ pan method, field plot method, Blaney-Criddle method and penman formula. ET can be measured by all methods above using different parameters involved. In this paper we discuss about measurement of ET by above all methods using software prepared by us in visual basic, this software takes the particular input from the user for particular methods and gives the output i.e. value of ET by that method. It also provides user the flexibility to compare the results of all the method. This provides great advantage by avoiding tedious calculations, user friendly, and easily comparing the results of various fields by various methods in almost no time. This software is in compact executable .exe file which avoids the process of installing it.