Spatio-temporal assessment of potential nonpoint pollution risk sources in the Chavantes reservoir basin, Brazil

Abstract

The interaction between civilizations and water resources throughout history has been closely tied to the emergence and evolution of societies. However, uncontrolled urban expansion and human activities that impact the natural environment have resulted in changes in land use, leading to environmental pollution. In this context, this research aims to assess and model the spatiotemporal influence of land use dynamics on the potential generation of diffuse pollutants using geospatial technologies within the Chavantes contributing basin in Brazil.Various techniques were employed to calculate the Potential Non-Point Pollution Index (PNPI) with specific adaptations. The PNPI was computed based on three sub-indicators: Distance Indicator, Run-off Indicator, and Land Cover Indicator, each representing distinct physical phenomena associated with proximity to water bodies, pollution transport considering geology, permeability, and prevailing land use characteristics. Hydrographic mapping was performed using ArcGIS Pro software, while land use data were obtained from MapBiomas.The research findings underscore a significant impact of land use dynamics in the Chavantes reservoir basin, resulting in an elevated PNPI. In conclusion, this study emphasizes the urgency of addressing diffuse pollution concerns in Brazil and highlights the necessity of refining country-specific indicators while advocating for the development of a dedicated methodology to calibrate these indicators.