Impacts of land use and land cover on ecosystem services in the Piancó-Piranhas-Açu River Basin

ABSTRACT Water resource management is closely tied to watershed conservation and the ecosystem services it supports. This study aimed to assess temporal changes in land use and land cover in the Piancó-Piranhas-Açu River Basin and evaluate their impact on ecosystem service provision. Covering 43, 683 km2 in northeastern Brazil, the basin was analyzed over a 30-year period from 1989 to 2019. Land use and land cover were mapped and classified using the semi-automatic classification plugin (SCP) with maximum likelihood classification. Categories identified included woody Caatinga vegetation, herbaceous-shrubby vegetation, water bodies, and exposed soil/urban areas. From 1989 to 2019, woody Caatinga and herbaceous-shrubby vegetation declined slightly by 3 and 2%, respectively, showing relative stability. In contrast, water bodies experienced a sharp 42% reduction, which underscores the critical role of water resource management in watershed planning. A total of 17 ecosystem services were identified, spanning regulatory, provisioning, and cultural categories. Economic valuation revealed a 24% decline in ecosystem service value - from US1, 970, 640. 38 in 1989 to US1, 509, 825. 52 in 2019 - highlighting the urgent need for effective water and land use planning to counteract the impacts of unsustainable resource use.