Uso e ocupação do solo, parâmetros limnológicos e Índice de Proteção da Vida Aquática como ferramentas integradas para análise da qualidade da água de nascentes

Abstract

The intensification of land use and occupation, especially due to the expansion of soybean monoculture, has caused changes in the natural landscape and compromised the quality of water resources, especially in spring areas located in Permanent Preservation Areas (APP). Considering the environmental relevance of the Dourados River Basin (MS), this study evaluated the impacts of land use and occupation on the water quality of three springs called NI, NII and NIII, with different percentages of riparian vegetation cover (>30%, between 10–30% and <10%, respectively). The methodology integrated limnological analyses (physical-chemical parameters and nutrients), remote sensing and the application of the Aquatic Life Protection Index (IVA), conducted between October 2021 and March 2022, during the soybean cultivation cycle. The data were analyzed by nonparametric statistical methods and Principal Component Analysis (PCA). The results indicated that the spring with the lowest vegetation cover (NIII) presented higher concentrations of total nitrogen and total phosphorus, evidencing the influence of intensive agriculture. The PCA revealed a positive correlation between vegetation and IVA in the most protected springs (NI and NII) and a negative correlation between IVA and intensive agriculture in the spring with the least protection (NIII). These findings reinforce the importance of riparian vegetation for maintaining water quality, indicating the need for integrated environmental monitoring strategies that combine geotechnology techniques, limnological analyses and ecological indices such as IVA.