Efeito dos usos da terra e da cobertura vegetal na temperatura superficial do solo da Bacia Hidrográfica do Córrego Piraputanga/MT - Brasil

Abstract

The suppression of natural vegetation and its replacement by monocultures implies changes in climate processes. The objective of this work was to investigate the average temperature of the different types of natural vegetation cover and land uses and the temporal variation of the total surface temperature in the Córrego Piraputanga Watershed/MT. The geoenvironmental characterization of the study area involved the generation of maps and geostatistical data from Geoeye satellite images and official cartographic bases. Land use and vegetation cover and average surface temperature data for each land use and vegetation cover class were obtained from Landsat 5 and 8 satellite images that were processed, classified and used to generate thematic maps and tables on the basin. To verify the significance of the average temperature difference between each class of vegetation and land use, the Kruskal-Wallis test and the Dunn post-test were performed, both tested with a significance level of 5%. When analyzing the average temperature of each use, it is observed that pastures and natural vegetation of the savannah type present higher temperatures when compared to forested surfaces. The highest average surface temperature was recorded in the pastures, reaching 41.71ºC. In contrast, the Evergreen Alluvial Seasonal Forest with emergent canopy had an average surface temperature of 38.91°C, almost 3°C lower than the pastures. In the temporal dynamics between the years 1990, 2000, 2010 and 2020, an increase in areas destined for pasture was identified, including in areas of permanent water preservation, resulting in a decrease in areas covered by natural vegetation, which affected the average surface temperature of the basin. It is essential that the economic activities carried out in the region are guided by the public authorities, which must encourage productive land use practices that dialogue with environmental conservation.