Caracterização geoambiental e escoamento superficial da Bacia Hidrográfica do Alto Corumbá (GO-DF)

Abstract

The dissertation addresses environmental analysis in the Alto Corumbá Water-shed (BHAC), an important region due to its hydrological function and natural resources. Over the last 40 years, BHAC has lost 13% of its native vegetation, mainly due to the expansion of agriculture and livestock farming. These changes have impacted surface water runoff, affecting soil infiltration. The ob-jective is the geoenvironmental characterization of BHAC, which revealed gen-eral and specific aspects of the studied area, such as a seasonal tropical climate, with average annual temperatures ranging from 22°C to 23°C and rainfall con-centrated between October and March. The area is predominantly semi-humid, representing 84% of the watershed. Geologically, the basin is part of the Bra-sília Belt, with emphasis on the Araxá Group, the Paleological Detrital-Lateritic Cover, and the Chapada dos Pilões, which make up a significant part of the area. Geomorphologically, it is dominated by the Dissected Plateau of the Upper Pa-ranaíba Basins (38.14%), with altitudes ranging from 923.5 m to 1,009.5 m and significant slopes that influence runoff. Pedologically, Cambisols and Latosols are the predominant soils, covering 36.9% and 57% of the area, respectively. Between 1985 and 2022, the watershed experienced intense changes in land use, with the expansion of agriculture (soybean) and pastures, while natural formations such as savannas and forests decreased significantly. Urban and agri-cultural growth impacted surface runoff, increasing local temperatures and re-ducing water availability. Another objective is the analysis of surface runoff. To understand these transformations, the research applied the Curve Number (CN) method, which measures the relationship between infiltration and surface runoff. BHAC was divided into nine sub-watersheds, analyzed in terms of cli-matic, geological, geomorphological, pedological, and land use aspects. The study revealed that intensive land use, especially for agriculture and livestock farming, significantly altered the region’s hydrological dynamics. As final con-siderations, we conclude that the sub-watersheds of Foz do Rio das Antas/Rio Capivari and Rio Capivari showed notable changes, with increased and de-creased infiltration, respectively. The most impacted sub-watersheds are a priority for conservation actions, highlighting the importance of sustainable man-agement for the protection of BHAC’s water and environmental resources.