Aplicação do zoneamento ambiental e produtivo para identificar áreas de potencialidades e limitações de uso na Bacia Hidrográfica do Ribeirão São Tomé, Noroeste do Paraná

Abstract

The Ribeirão São Tomé watershed area, located in northwestern Paraná State, Brazil, like the entire region, has experienced extensive deforestation and has been intensively used for agriculture since the 1950s. Intensive use of the sandy soils, formed from the alteration of arenite in the Caiuá Group, has led to environmental problems and depletion of natural resources, especially soil, throughout the northwest region. Given the watershed’s agricultural potential and strategic position, understanding current land use and the conservation status of its natural resources is essential for supporting effective environmental management and informing public policies. This study applied the Environmental and Productive Zoning (Zoneamento Ambiental Produtivo - ZAP) methodology, combined with an analysis of morphometric relief variables, to assess conservation potential and usage limitations, as well as to identify watershed sectors most susceptible to erosion. Results indicated that mid- and lower-slope sectors are more susceptible to erosive processes, as these areas concentrate greater volumes of water flow. Overall, the watershed demonstrates a high conservationist use potential (Potencial de Uso Conservacionista (PUC), with variables reflecting favorable conditions for groundwater recharge. Although the watershed area is heavily utilized for agriculture, particularly for sugarcane cultivation, no critical issues were identified in the rural zone concerning land use and water resources that would compromise water pressure or availability, reflecting the adoption of good practices, notably terracing and minimal or no soil tillage. Isolated areas in the peri-urban sector of the watershed display large erosive features (rills and gullies) that require attention and intervention from local authorities. Overall, the study area shows a positive conservation status compared to the broader environmental degradation observed in the northwest region over recent years. The ZAP methodology applied to the Ribeirão São Tomé watershed can serve as a valuable tool for planning and management by municipal and state governments