Net Radiation in the Semiarid Region of the States of Paraíba and Rio Grande do Norte Using the MODIS Sensor

Abstract

This study aimed to estimate the surface net radiation (Rn) for the States of Paraíba and Rio Grande do Norte and validate the results with data measured in validate the results with measurements in experimental recovering (CRec), degraded (CDeg), and preserved (CPres) areas of Caatinga. Seventeen images of the MODIS sensor on board the Terra satellite were selected for CRec and CDeg in the State of Paraíba and twenty-eight images for CPres in the state of Rio Grande do Norte, corresponding to the period of January to December 2014. The MODIS-Terra MOD09A1 and MOD11A2 products were used. Parametric (Shapiro-Wilk) and non-parametric (Kolmogorov-Smirnov and Wilcoxon-Mann-Whitney) tests were applied to understand the patterns. Statistical error indices were applied to verify the accuracy of the estimates in relation to the observed values. Only the measured albedo (α_meas) met the assumption of normality. According to mean absolute percentage error statistics, the model used to estimate the albedo was classified as inappropriate for CPres and CRec ( 25%), while it was satisfactory for CDeg (15-25%). Significant differences between observed and estimated values were absent only for the variable Rn in the three observation sites. The good performance of Rn estimates confirms the efficiency of the application of the method in semiarid regions.

Balanço de Radiação no Bioma Caatinga no Semiárido Alagoano

“…Para Silva et al (2022) clima, extrativismo, manejo agrícola inadequado e sobre pastoreio são os principais fatores que alteraram a vegetação nativa que compõe a floresta seca da Caatinga. Certamente os impactos decorrentes das alterações da cobertura vegetal ocorrem devido às mudanças nas características biofísicas.…”