Assessment of Pluvial Flood Mitigation Ecosystem Service in a Riverside City Using the Integrated Valuation of Ecosystem Services and Tradeoffs Model for Ecological Corridor Mapping

Riverside cities are vulnerable to pluvial flooding due to multiple factors, such as landscape fragmentation caused by land-use changes, which weakens the ecosystem service of pluvial flood mitigation. This ecosystem service is essential because it reduces the impact of this climatic event through water infiltration into the soil. The metropolitan area of Arequipa, Peru, a riverside city, is currently fragmented by accelerated population growth, which has filled the river buffer zones and agricultural areas with concrete, resulting in a fragile flood control ecosystem service. This research assesses the pluvial flood mitigation ecosystem service in the metropolitan area of Arequipa using the InVEST software 3.12.1 to map an ecological corridor. The results show low runoff control in urban environments but significant retention in agricultural and non-agricultural vegetation areas. Zero-runoff patches were identified as ecological sources, and a resistance surface map and least-cost path model were created, yielding a 57 km ecological corridor connecting 18 ecological sources across 12 of Arequipa’s 19 metropolitan districts. This study highlights the importance of integrating ecosystem services into urban planning to support green infrastructure initiatives, which contribute to sustainable and resilient cities by mitigating fragmentation and enhancing natural flood defenses.