Estimativa do balanço de radiação na região semiárida dos Estados da Paraíba e Rio Grande do Norte utilizando o sensor Modis.

Abstract

Studies related to energy exchange through ecosystems and the atmosphere are relevant to understanding how vegetation runs the local microclimate, however being very scarce when referring to the Caatinga vegetation. This study aims to evaluate the components of the radiation balance from multispectral sensor data of high and moderate spatial resolution (MODIS / TERRA) and validate with data from micrometeorological towers in Caatinga area in recovery, degraded and recovered. In order to estimate the net radiation (Rn) for semi-arid regions it is interesting to use remote sensing (RS), because it does not often be measured at weather stations, because it depends on the nature of the surface and consequently suffers been great influence on some variables (albedo and surface temperature). First, have been used data from the MODIS (MODIS) aboard the Terra satellite for the year 2014, covering the areas of the States of Paraíba and Rio Grande do Norte to estimate the Rn and then the results were validated with data of micrometeorological towers. Use only SR data (MODIS/TERRA) was a useful proposition for estimation and spatial distribution of components of the Rn in the semiarid region. The data measured in the field are of fundamental importance for the validation of model results, by having more realistic behavior for a specific location. It was also possible to observe an unusual behavior in results across PB, where the area degrades presented NDVI larger and albedo smaller than the area of retrieval, this behavior can is associated with the absence of rainfall in the area in recovery, and for estimating the Rn was calculated the average percentage error and the results were satisfactory getting around 20%.