Nature-based Solutions at the Interface of Hydro-Environmental Science, Social Justice, and Complex Decision-making

One of the greatest threats facing civilization is climate change and the associated impacts to biodiversity, hydro-meteorological hazards, environmental degradation, and social vulnerability. We have the opportunity to mitigate such negative effects by embracing the restorative power of nature and strategically incorporating natural systems within the built environment. Nature-based solutions (NBSs) encompass various types of green infrastructure, which combine earthen and engineered materials, to reduce the flow of stormwater and capture pollutants at the source of collection. By increasing greenspace within the built environment, NBSs also store carbon emissions, improve societal well-being, and restore ecosystem health. However, NBSs have not reached their full potential due to an inadequate understanding of how hydro-environmental dynamics and social characteristics interrelate within the overall system, particularly at the level of human activity and urban planning (i.e., the watershed-scale). Moreover, NBS implementation has been constrained due to elusive institutional and societal barriers that have yet to be fully understood and positioned within actionable policy frameworks. The challenges facing NBS adoption are not purely qualitative nor quantitative, as they exist at an interface between the social and physical sciences. Historically, much of the work involving human-water systems has been conducted in rural environments, due in part to challenges of urban stormwater modeling. In order to foster sustainable solutions within the built environment, we must extend our systems-thinking approaches to thoroughly entangle one of the most complex systems available: the flood-prone metropolis. As such, this study amalgamates hydro-environmental science, social justice, and complex decision-making using intersectoral approaches to strengthen NBS adoption within the urban environment. Specifically, this study bridges disciplinary divides to 1) advance NBS policy-making using stakeholder cognition and properties of network theory, 2) address overlapping NBS functionalities by developing a novel spatial data infrastructure system for the entire contiguous United States, and 3) optimize NBS planning at the watershed-scale by balancing economic, environmental, and social characteristics. NBSs are investigated as a holistic human-environmental system with many vantage points for analysis, thereby eliciting novel causal connections across institutional and spatial planning scales.