The development of evapotranspiration for upland irrigation planning by the AMeDAS meteorolgical data

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A reference evapotransipiration that is the most important factor in upland field irrigation is calculated by the Penman's method using the meteorological data. There are about 840 weather stations in Japan where air temperature, solar radiation, and so on are measured. Those data have been measured for about 20 years since the start of AMeDAS measurement and can be used for the Penman' equation. The objective of this study was to develop a database on the hard disk in a computer to take out the necessary data from the database. The user can select the target observation location, meteorological factors, and the observation term and can calculate the average values, the cumulative values, and the reference evaporation by Penman's equation. Those results are output into a data file and displayed as a contour map or a plot of equi-values. The system program was coded by a Microsoft Visual Basic language.On the other hand, the crop coefficient is needed to estimate the actual evapotranspi … More ration using a reference evapotranspiration calculated by the Penman's equation. In Japan, there are few data of crop coefficients for various kinds of crops, and therefore it is needed to measure much more data for the detailed upland irrigation planning. Dr. Miura who is a head investigator has measured the evapotranspiration at different upland fields using the micrometeorological method and rearranged those results as crop coefficients. Furthermore, he has set up the long-term measurement system of radiation balance to test the predictive equation of net radiation based on measured values. The differences of sunshine duration due to the different instruments of heliograph have reported, however, the result for the predictive equation of net radiation has not reported.In this report, some papers that have already been published are classified into four categories, that is, the relationship between AMeDAS and Penman's equation, the measurement of micrometeorology in upland field, the upland field irrigation, and the meteorological environment. More papers will be published in the future. Less