Author(s): Yénica Cirila Pachac Huerta, Eduardo Abraham Chávarri Velarde
Keywords: Evapotranspiration; Remote sensor; SEBAL algorithm;
Abstract: The objective of the research was to estimate spatially the evapotranspiration (ET) of maize with the help of remote sensing using the SEBAL algorithm for the conditions of the Huaylas valley, Huaraz (Perú), during the year 2016. The algorithm was programmed with the Builder ArcGis model for 12 LANDSAT 8 satellite images from 14/may/2016 to 06/november/2016 with a temporal variability of 15 days. At the same time, a maize plot of 2 ha was monitored at the Cañasbamba Research Center of the National University Santiago Antúnez de Mayolo, Huaraz (Perú). The meteorological data were obtained from Cañasbamba and Tingua stations. Lysimeter results indicated a minimum ET of 2.68 mm/day on 09/june/2016, an average ET of 3.93 mm/day and a maximum ET of 5.9 mm/day on 04/september/2016. Likewise, 11 maize monitoring points distributed in the study area were considered, due to the fact that the beginning of sowing depends on the owners of the agricultural lands, varying by days or months. When comparing the observed and measured real evapotranspiration, a relative error of 0.08, the root of the quadratic mean error of 0.3, a determination coefficient of 0.94 and a Nash-Sutcliffe efficiency of 0.91 were obtained, the results obtained with the SEBAL algorithm being satisfactory. In the study area located between the districts of Yungay and Carhuaz, Huaraz (Perú), mean values ranging from 4.0 mm/day to 6.2 mm/day were found throughout the analysis period.