Nature-based solutions (NbS) are becoming increasingly popular in cities around the world; however, such efforts have not been widely incorporated into analyses of urban flood vulnerability nor the total population and property loss of flooding to date, except for a few studies that examined the effectiveness of green infrastructure or only wetlands in flood regulation. The proposed research sought to understand if the existing pattern and composition of NbS can mitigate flood vulnerability and loss of flooding in one of the fastest urbanizing regions in the United States, the Philadelphia Metropolitan Area. This research made key contributions to our understanding of how urban areas can grow without exacerbating flooding and inequity.First, a systematic mapping was conducted to reveal the most common spatial metrics of NbS that mitigate urban flooding in countries around the world. These findings identified important research areas for urban geographers, policymakers, planners, and civil engineers. This review indicated that the effectiveness of NbS varies spatially based on land use/land cover, climatic, and other contextual factors. The results indicated that the location, distribution, and arrangement of NbS may have different impacts on runoff mitigation and flood loss. Also, flood hydrology was the most common topic addressed, and the spatial configuration of NbS, especially connectivity was consistently identified as an important factor in flood regulation. Second, the potential of NbS as a flood loss mitigation tool in one of the fastest-growing and flood-prone counties of Pennsylvania, Montgomery County, using the Generalized Linear Model (GLR) and Geographically Weighted Regression (GWR) techniques was examined. The findings partially contradicted previous research by revealing an unexpected relationship between NbS quantity in floodplains and expected annual loss. Findings also demonstrated that lower-sized and disconnected patches of NbS in floodplains in some dense urban areas effectively reduce total losses from flood events. Third, the spatial coincidence between the density of NbS and flood vulnerability within eight neighboring urbanizing regions situated in Montgomery County was analyzed by using the Local Indicator of Spatial Association (LISA). The results of LISA identified regions of concern characterized by elevated flood vulnerability scores and reduced concentrations of two tree canopy types as well as shrubs and grasses. Taken together, these results emphasize the significance of strategically integrating and improving NbS, especially in areas grappling with distinct flood-related issues. It also emphasized the potential for significant enhancements in flood resilience and mitigation policies thoughtful urban planning and the adoption of NbS. / Geography