UC Berkeley

This dissertation adopts a social-ecological systems approach to examine two water-related problems resulting from global environmental change driven by urbanization and climate change. The first problem is the need to adapt coastal regions to rapidly rising seas; the second problem is the degradation of stormwater quality entering water bodies. In taking a social-ecological systems approach, this dissertation considers how human and biophysical processes are interconnected and interactive in shaping the outcomes of these problems. To do so, this dissertation combines methods, knowledge, and theory from environmental planning, ecology, and environmental engineering.

On coastal adaptation to sea level rise, this dissertation develops an analytical framework to examine the interconnections between human and non-human adaptation. The analytical framework identifies positive and negative shifts in vulnerability between human and non-human actors across a number of dimensions. It is deployed in a literature review on the topic of wetland migration mainly focused on the US, showing multiple ways that humans and wetland ecosystem shift vulnerabilities between them across physical, economic, environmental, social, cultural, and institutional dimensions. But it also shows that synergies are possible between human and wetland adaptation to sea level rise. Whether positive or negative, these vulnerability shifts reflect particular biophysical, historical, and social contexts and can operate on multiple spatial and temporal scales.

Next, the dissertation investigates in depth one kind of interconnection between human and non-human adaptation. Using an ecological model, it explores how the hydrodynamic effects of hardening or softening shorelines could 1) influence the ability of coastal wetlands to adapt to sea level rise and 2) change vegetative cover. Although focused on a case study in San Francisco Bay, California, US, the methods address multiple coastal contexts. It contributes an understanding of how human actions to adapt to sea level rise by hardening or softening shorelines could create both positive and negative ecological impacts to wetlands at a regional scale. It exposes tradeoffs that decision-makers may need to consider that span spatial and temporal scales.

Finally, on stormwater quality, this dissertation analyzes the relationships between human and natural processes in producing stormwater pollution. The analysis centers on a large dataset of stormwater samples from 182 watersheds in 26 metropolitan areas in the US, combined with other ancillary datasets. It uses machine learning to identify patterns in the data that quantify how land use and land cover (human factors), along with climate and weather (natural factors), relate to stormwater pollution. These patterns are described as relationships between geography and stormwater “signatures,” defined as unique combinations of stormwater contaminants. This work advances an understanding of how contaminants in stormwater co-occur together as signatures, and how those signatures are then related to human and natural factors. It also contributes a comparative understanding of stormwater quality across the US. Overall, this dissertation demonstrates complex interconnections between human and biophysical systems that support the need for cross-sectoral, cross-scalar environmental planning.