Science Serving Maryland's Coasts


Understanding the Complex Roles that Green Infrastructure Can Play in Improving the Resilience of Coastal Urban Zones

Principal Investigator: 

David Tilley

Start/End Year: 

2015 to 2017


University of Maryland, College Park

Co-Principal investigator: 

Rhea Thompson

Strategic focus area: 

Resilient communities and economies


A vast amount of the U.S. population lives in coastal urban environments which tend to be exposed to more risks from climate change. Conversion of coastal ecosystems to human developments has decreased the diversity of flora and fauna. Implementation of green infrastructure—GI (e.g., green roofs, stormwater wetlands) promises some deferment of the increased risk of living in coastal cities and the restoration of coastal ecological functions. Proper implementation of GI in low lying coastal zones has the potential to increase the diversity of environmental, economic and health benefits. Unlike traditional ‘hard’ engineering approaches that historically viewed problems in isolation and solutions in singular terms, climate change presents multifaceted issues which require multipronged solutions. GI, by relying on natural processes and energies for its ability to reduce flooding, decrease heat waves, enliven the local environment and provide ecological habitat, has the ability to increase the resilience of coastal communities and their environments, and adapt to climate change. To fully appreciate the multiple benefits provided by GI, new complexity metrics are needed. In ecology the Shannon Diversity index has been used often to relate species diversity to ecosystem resilience. Since GI benefits are diverse and not easily ‘additive’, we propose that the environmental accounting technique of emergy evaluation can be extended using information theory—the basis of the Shannon Index—to enumerate the energetic diversity of GI and provide a new metric of resilience. GI depends on a diversity of natural energy inputs (i.e., sun, water, atmospheric deposition) to produce a variety of outputs that can be quantified in the same unit using emergy. By integrating information theory with emergy evaluation, we will be able to quantify how much GI increases the flow of information at the ecological, environmental, social and economic levels. GI, by relying on a host of natural energies to produce an excess of benefits, should have high information. This project is focused on developing a more refined appreciation of the beneficial complexity that GI has to offer. Researchers will develop a model that integrates information theory with energy accounting to understand the role of GI in urban environments. They will use WaterShed; inspired by the rich, complex ecosystems of the Chesapeake Bay, it is the 2011 winning home designed and built by researchers and students at the University of Maryland for the U.S. Solar Decathlon competition. Evaluation of the energy savings and retention benefits of WaterShed’s green roof, will provide the researchers with a real system for validating their theory. An integrated monitoring system evaluating on-site weather, water and energy fluxes within the green roof will be used to determine benefits. An excel based model that evaluates GI benefits and sustainability has been developed as a part of the graduate fellow's dissertation research. Broader impacts include integrating resilience metrics into the model so it can be used as a decision-making tool in assessing GI sustainability and resilience in coastal urban communities.