Identificação da fragilidade ambiental e de serviços ecossistêmicos de regulação hídrica como suporte à proposta de pagamento por serviços ambientais para a unidade hidrográfica de gerenciamento de recursos hídricos Alto Ivaí, Paraná

Abstract

This work aimed to identify the environmental fragility and the potential of water regulation ecosystem services in seven municipalities located in the Alto Ivaí Water Resources Management Unit, belonging to the Ivaí River Hydrographic Basin, Paraná state, and to discuss the feasibility of a Payment for Water-related Environmental Services (PWES) program as a water management instrument. The methodology was based on the physical (climate, soils, slope, and hypsometry) and socioeconomic characterization of seven municipalities in the basin, followed by an environmental fragility analysis that integrated data on land use and cover, slope, and climate. Subsequently, the water-related Permanent Preservation Areas (PPAs) were delimited and quantified, and an economic-ecological valuation, with a strategic focus on spring PPAs, was carried out to estimate the financial potential of a PWES program. The results indicated a predominance of areas with "Very High" environmental fragility, resulting from the conflict between intensive agricultural use and the characteristic of the undulating relief. A total of 8,408.96 hectares of water-related PPAs were identified; however, the valuation was strategically directed at the 14.31 hectares of spring PPAs, due to their water priority, resulting in an estimated annual financial reward between R$ 13.8 thousand and R$ 54.8 thousand through a PWES program. It is concluded that the basin possesses a strategic natural capital and that the implementation of a PWES in springs constitutes an ecologically necessary and financially viable strategy to align agricultural production with water security, promoting the conservation of the natural resources that sustain the region itself.