Changes in land use and cover and their consequences on the spatial distribution of evapotranspiration and climatic elements in southwest Piauí, MATOPIBA

Abstract

With the advance of agriculture in Brazil, the occurrence of environmental disturbances that can reach different levels, such as the change of use and land cover, is perceived. In the southwest of Piauí, it is noticeable the large portion of Cerrado that has been replaced by crops and pastures, resulting in several impacts, such as changes in evapotranspiration. In the literature there are several methods to estimate it, among them the remote sensing techniques stand out. Therefore, the objective of this work was to quantify agricultural expansion and understand its consequences on real evapotranspiration and on the configuration of meteorological elements in the municipality of Baixa Grande do Ribeiro, through the products of the United States Geological Survey (USGS) accessed through Google Earth. Engine. Platform (GEE), between 2000 and 2020. The real evapotranspiration (ETa) and leaf area index (LAI) data come from the MODIS sensor products. The meteorological data were obtained from the website of the National Aeronautics and Space Administration Prediction Of Worldwide Energy Resources (NASA POWER). The maps were made in QGIS 3.18.1 software from data processed on the GEE platform. The evolution of forest and agricultural areas and images of land use and cover were obtained using the MapBiomas platform. It was observed that between 2000 and 2020, about 27% of the area of native vegetation was replaced, and soybean cultivation grew by approximately 2618%. In addition, the removal of native vegetation for the establishment of pastures and agricultural crops has contributed to the reduction of evapotranspiration and the leaf area index, in addition, it may be associated with the increase in surface and air temperatures and reduction of the relative humidity of the air. This implies the need to create and implement public policies aimed at controlling deforestation in the region, as well as greater inspection in the sphere of environmental crimes.