Spatialization of Instantaneous and daily average net radiation and Soil Heat Flux in the Territory of Itaparica, Northeast Brazil

摘要

This work has as aim to quantify the energy changes between atmosphere and surface by modeling both net radiation and soil heat flux related to land use and land cover. The methodology took into account modeling and mapping of physical and biophysical parameters using MODIS images and SEBAL algorithm in an area of native vegetation and irrigated crops. The results showed that there are variations in the values of the estimated parameters for different land cover types and mainly in caatinga cover. The dense caatinga presents mean values of soil heat flux (Go) of 124.9 Wm"2 while sparse caatinga with incidence of erosion, present average value of 132.6 Wm~(-2). For irrigated plots cultivated with banana, coconut and papaya the mean Go values were 103.8, 98.6 and 113.9 Wm~(-2), respectively. With regard to the instantaneous net radiation (Rn), dense caatinga presented mean value of 626.1 Wm-(-2), while sparse caatinga a mean value of 575.2 Wm~(-2). Irrigated areas cultivated with banana, coconut and papaya presented Rn of 658.1, 647.4 and 617.9 W m~(-2), respectively. Applying daily mean net radiation (Rn_(DAVE)) it was found that dense caatinga had a mean value of 417.1 W m~(-2) while sparse caatinga had a mean value of 379.9 W m~(-2). For the irrigated crops of banana, coconut and papaya the Rn_(DAVE) values were 430.9, 431.3 and 411.6 W m~(-2), respectively. Sinusoidal model can be applied to determine the maximum and Rn_(DAVE) considering the diverse classes of LULC; however, there is a need to compare the results with field data for validation of this model.