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- All Subjects: Climate Change
- All Subjects: urban planning
The EcoCode resembles a typical form-based code in structure, but at a smaller geographic scale. General Provisions describes the context of the surrounding area that must be assessed before choosing to create an EcoBlock. Development and Adoption strategy explains the evolving role of the EBO and how the realization of this design is currently envisioned. Regulating Block, Block Development Standards, Building Envelope Standards, and Building Development Standards describe the detail that will need to be developed for the physical aspects of each block. Streetscape Standards describe the vision of the EBO as applicable to the streets surrounding an EcoBlock. Finally, the Sustainability Standards contain the contribution of each board member of the EBO with their unique expertise on implementing the design principles.
As a supplement to The EcoCode itself, this document contains three topics for case studies looking into the feasibility of the EcoBlock as a whole: shared space, net-zero energy, and mixed-income housing. Shared space development and management uses Montgomery Park in Boston to show the potential of community-based organization while warning against gentrification. The West Village campus of the University of California in Davis shows the technical possibility and the financial challenges of a net-zero community. Brogården, an affordable housing community in Sweden, demonstrates the possibility for decreasing energy consumption in public housing. Finally, Via Verde in New York City is an example of combining health, green space, and affordability in a mixed-income housing development. Though there is not yet an example of a fully implemented EcoBlock, these case studies speak to the challenges and the facilitators that the EBO will likely face.
Motivated by the need for cities to prepare and be resilient to unpredictable future weather conditions, this dissertation advances a novel infrastructure development theory of “safe-to-fail” to increase the adaptive capacity of cities to climate change. Current infrastructure development is primarily reliant on identifying probable risks to engineered systems and making infrastructure reliable to maintain its function up to a designed system capacity. However, alterations happening in the earth system (e.g., atmosphere, oceans, land, and ice) and in human systems (e.g., greenhouse gas emission, population, land-use, technology, and natural resource use) are increasing the uncertainties in weather predictions and risk calculations and making it difficult for engineered infrastructure to maintain intended design thresholds in non-stationary future. This dissertation presents a new way to develop safe-to-fail infrastructure that departs from the current practice of risk calculation and is able to manage failure consequences when unpredicted risks overwhelm engineered systems.
This dissertation 1) defines infrastructure failure, refines existing safe-to-fail theory, and compares decision considerations for safe-to-fail vs. fail-safe infrastructure development under non-stationary climate; 2) suggests an approach to integrate the estimation of infrastructure failure impacts with extreme weather risks; 3) provides a decision tool to implement resilience strategies into safe-to-fail infrastructure development; and, 4) recognizes diverse perspectives for adopting safe-to-fail theory into practice in various decision contexts.
Overall, this dissertation advances safe-to-fail theory to help guide climate adaptation decisions that consider infrastructure failure and their consequences. The results of this dissertation demonstrate an emerging need for stakeholders, including policy makers, planners, engineers, and community members, to understand an impending “infrastructure trolley problem”, where the adaptive capacity of some regions is improved at the expense of others. Safe-to-fail further engages stakeholders to bring their knowledge into the prioritization of various failure costs based on their institutional, regional, financial, and social capacity to withstand failures. This approach connects to sustainability, where city practitioners deliberately think of and include the future cost of social, environmental and economic attributes in planning and decision-making.
Further, I investigated the effect of precipitation variation on functional diversity on the same experiment and found a positive response of diversity to increased interannual precipitation variance. Functional evenness showed a similar response resulting from large changes in plant-functional type relative abundance including decreased grass and increased shrub cover while functional richness showed non-significant response. Increased functional diversity ameliorated the direct negative effects of precipitation variation on ecosystem ANPP but did not control ecosystem stability where indirect effects through the dominant plant-functional type determined ecosystem stability.
Analyses of 80 long-term data sets, where I aggregated annual productivity and precipitation data into five-year temporal windows, showed that precipitation variance had a significant effect on aboveground net primary production that is modulated by mean precipitation. Productivity increased with precipitation variation at sites where mean annual precipitation is less than 339 mm but decreased at sites where precipitation is higher than 339 mm. Mechanisms proposed to explain patterns include: differential ANPP response to precipitation among sites, contrasting legacy effects and soil water distribution.
Finally, increased precipitation variance may impact global grasslands affecting plant-functional types in different ways that may lead to state changes, increased erosion and decreased stability that can in turn limit the services provided by these valuable ecosystems.