Potencial de escoamento superficial, de erosão acelerada e de poluição difusa na Bacia Hidrográfica do Rio Potengi - RN

Abstract

This study aimed to delineate and analyze the potential for surface runoff, accelerated erosion, and diffuse pollution in the Potengi River Basin (PRB), focusing on the identification of priority areas for conservation and restoration. An integrated Multi-Criteria Decision Analysis (MCDA) methodology was applied in a GIS environment, which incorporated geo-environmental attributes such as geological units, slope, thickness of unconsolidated materials, permeability, drainage density, surface storage features, landforms, rainfall, land use and cover, erodibility, soil texture, and phosphorus and organic matter content. The results indicated that the PRB is predominantly characterized by low and moderate surface runoff potentials (98.44% of the area), although approximately 60.91% of the area presents a high risk of accelerated erosion due to a combination of factors such as steep slopes and highly erodible sandy soils. About 38.96% of the watershed area showed high to very high diffuse pollution potential, highlighting water vulnerability and the need for integrated management strategies, such as the recovery of riparian vegetation. The analyses underscore the importance of actions to mitigate the impacts of erosion and pollution, promoting environmental sustainability in the PRB. Additionally, the methodology proved effective in characterizing these processes, offering an approach that is replicable in other watersheds, especially in semi-arid regions where environmental pressures are intense and natural vulnerability is high. Methodological innovations in obtaining some of these attributes, such as for storage features, drainage density, and erodibility, as well as using sand and clay fractions to address soil texture in map algebra, enhanced cartographic representation, providing a more precise and grounded spatial analysis.