Spatial distribution of biophysical parameters in the Ipanema River Basin using remote sensing techniques

Abstract

Remote sensing techniques obtain essential information about the biophysical parameters at the interface earth's surface and atmosphere that are important for observing the vegetation conditions in the different land uses and occupations, especially in survey directed to hydrographic basins. The objective of this study was to evaluate the spatial distribution of biophysical parameters in the Ipanema River basin by remote sensing. An image of Landsat 8 OLI/TIRS satellite was used, on the date of passage November 14, 2015, covering the all study area of Ipanema River basin, located in the Brazilian semiarid region. The image was processed by ERDAS IMAGINE® 9.1 Software. Radiometric calibration and conversion to radiance and reflectance were performed with the surface data using the SEBAL algorithm. The meteorological data were collected from an automatic station belonging to INMET, located in the study area. The thematic maps of the biophysical parameters albedo, land surface temperature (Tsup) and the radiation balance (Rn) were processed by ArcGIS® 10.2.2 Software. The descriptive statistics were used to determine the differences of these parameters in relation to the local climate of the region and anthropic actions. Radiation balance (Rn) was closely related to the albedo spatial patterns and surface temperature. The highest values of Rn were represented by the lowest albedo values. The results obtained corroborate with those present in the literature and show spectral behavior typical of targets that integrate the classes of land use and occupation in the semiarid region during the dry season, evidencing that the SEBAL algorithm can be used with great potential for estimation of radiation balance.