algorithm sebal

In horticultural plants, determining of evapotranspiration because of problems in the direct measurement such as installing large lysimeter and length during tree growth, estimated indirectly on the basis of meteorological data. With regard to the spatial variability of meteorological parameters and sometimes inappropriate distribution of meteorological stations estimating evapotranspiration is not possible with sufficient accuracy. Therefore, use of procedures such as the methods remote sensing based that consider these changes may be best. In this study, evapotranspiration pomegranatee trees measure and were determined with direct and indirect methods in Tarom district of Zanjan at different physiological growth stages and In 1393 and 1394 growing seasons. In the direct method were measured Water balance components and the indirect method were determined with the help of satellite images actual evapotranspiration trees with SEBAL algorithm. Then The crop coefficient was determined using evapotranspiration obtained by the two methods and determination of the reference evapotranspiration based on meteorological data of day of receiving the image, and the results are compared and evaluated. The correlation coefficient in evapotranspiration for first and second year was 0.83 and o.79 respectively and a total of two years was 0.63, respectively, and about of crop coefficient this coefficient was 0.97 and 0.94 and a total of two years was 0.94

In horticultural plants¡ determining of evapotranspiration because of The existing problems in the direct measurement such as installing large lysimeter or the exact equipment and length during tree growth¡ often estimated indirectly and on the basis of meteorological data. With regard to the spatial variability of meteorological parameters and sometimes inappropriate distribution of meteorological stations estimating evapotranspiration is not possible with sufficient accuracy. Therefore use of procedures such as the remote sensing methods that consider these changes is best. In this study¡ evapotranspiration of olive trees were measured and determined with direct and indirect methods in two growing seasons 1393 and 1394 in Tarom district of Zanjan at different development stages. The actual evapotranspiration were determined by direct method¡ By measuring the moisture balance components and in the indirect method with help from the satellite imagery of landsat 8. Then by determining of the reference crop evapotranspiration¡ olive crop coefficient were calculated and were compared and evaluated. The results showed that calculated evapotranspiration and plant coeffiecient of remote sensing mehod in various olive growth stages matched with moisture balance data. So that¡ evapotranspiration correlation coefficient was 0.73¡ 0.87 and 0.82 for first¡ second and cumultative year¡ respectively. Moreover¡ correlation coefficients of plant coefficient was 0.95¡ 0.62 and 0.86¡ respectively. It is concluded that remote sensing method can be useful to estimate evapotranspiration of olive tree.