Prioritizing Urban River Restoration Management Practices: A Cross-Evaluation Using the Criticality Index for Watershed Restoration (CIWR) and Opportunity Layers

Abstract

Urbanization exerts significant stress on urban river ecosystems, leading to their degradation and the loss of environmental functions. Several studies have focused on restoring these urban rivers to enhance environmental quality and contribute to overall city well-being. However, such restoration efforts encounter economic, environmental, and social challenges. This study proposes a methodological framework to aid public managers in prioritizing areas for urban river restoration. The approach integrates the concept of environmental services with urban development opportunities to address these dual demands. Central to this framework is the introduction of the criticality index for watershed restoration (CIWR), which categorizes watershed areas based on environmental quality indicators, using river restoration as a guiding principle. Additionally, legally protected environmental areas were considered as opportunity layers. This study used geographic information systems (GIS) to manage and overlay datasets for a case study in the João Mendes Watershed in Niterói, southeast Brazil, which illustrated the use of the CIWR. By intersecting this framework with the opportunity layers, priority locations were identified for potential river restoration management practices. The results indicated that the overall criticality condition of this watershed for river restoration is low. The study further discusses potential measures for river restoration in the identified priority areas, underscoring the importance of strategic planning in urban environmental management. The CIWR proved to be an easily applicable and replicable management decision tool for comparing watersheds and assessing deficient environmental services, with both numerical and spatial results. Its use, combined with the “opportunity” layer, enables public managers to define priority areas for river restoration practices based on clear and objective criteria.