D4. Ecology and resilience

Urban design principles for flood resilience

Aims and method:

Examines the flood responses of rural hamlets in Vietnam to develop design principles for cities to improve infrastructural flood response. A total of 34 semi-structured interviews were conducted in Vinh An and Ha Bao, Vietnam before, during, and after seasonal flooding 2014.

Key Findings:

· Development should anticipate and accommodate flooding through design: use of stilts; open spaces designed to flood; and raised footpaths and pedestrian walkways;

· Design with nature: reinstate riverfronts, marshlands, and floodplains to allow ecological processes to re-establish themselves;

· If design accommodated natural phenomena such as flooding then this leads to a greater sense of well-being and an appreciation of the positive side of flooding and nature.

Reference:

Liao, K. H., Le, T. A., & Van Nguyen, K. (2016). Urban design principles for flood resilience: Learning from the ecological wisdom of living with floods in the Vietnamese Mekong Delta. Landscape and Urban Planning, 155, 69-78.

http://www.sciencedirect.com/science/article/pii/S0169204616300494

Eco-hydrology and good urban design

Aims and method:

Examines how urban storm water logging (USWL) may be more effectively managed through a combination of ecohydrology and good urban design. Reviews the 7.21 rainstorm of 21 July 2012 to understand the causes (mainly climate change, increasing imperious surfaces, the limited capacity of drainage system, lack of policy enforcement and lack of public awareness) and consequences of Beijing’s built form and its impact on storm water management.

Key Findings:

· Combining eco-hydrology with good urban design provides a framework for better managing storm water in Beijing by connecting the built environment more effectively with the natural landscape.

· Increasing greenspace, using water and other natural features as place making devices and incorporating more permeable surfaces in the built environment may significant improve Beijing’s ability to manage storm water.

Reference:

Li, C. (2012). Ecohydrology and good urban design for urban storm water-logging in Beijing, China. Ecohydrology & Hydrobiology, 12(4), 287-300.

http://www.sciencedirect.com/science/article/pii/S1642359312702112

Ecosystem performance and density

Aims and method:

Evaluates the relationship between urban form and ecosystem performance (availability and patch characteristics of tree cover, gardens and green space; storm-water run off; maximum temperature; carbon sequestration) in five UK cities. Multiple quantitative indices were developed and evaluated using regression models.

Key Findings:

· High density urban developments are generally associated with poor ecosystem performance.

· Although most measures of ecosystem performance declined with increasing urban density, there was considerable variability in the relationships. Therefore, at any given density, there is substantial scope for maximising ecological performance.

· Variations across sites are driven by the introduction and maintenance of green spaces (grass verges, etc.) and trees in city centres.

Reference:

Tratalos, J., Fuller, R. A., Warren, P. H., Davies, R. G., & Gaston, K. J. (2007). Urban form, biodiversity potential and ecosystem services. Landscape and Urban Planning, 83(4), 308-317.

http://www.sciencedirect.com/science/article/pii/S0169204607001375

Urbanisation and species richness

Aims and method:

Examines the relationship between urban development and species richness (plants, mammals, reptiles, amphibians and insects) to discern what, if any pattern there is between the two processes. Uses a meta-analysis of 105 existing studies to quantitatively evaluate the species richness across an urban-rural gradient in Asia, North and South America, Europe and Australia.

Key Findings:

· Extreme urbanisation (representative of urban cores) almost always reduces species richness.

· Most plant studies (65%) show increasing species richness with moderate (suburban) urbanisation

· A minority (30%) of invertebrate studies and a very small minority (12%) of non-avian vertebrate studies show increasing richness.

Reference:

McKinney, M. L. (2008). Effects of urbanization on species richness: a review of plants and animals. Urban ecosystems, 11(2), 161-176.

https://link.springer.com/article/10.1007/s11252-007-0045-4

Green/blue space availability and energy use

Aims and method:

Examines the various impacts of urban household energy use / carbon emission in Xiamen, China. Using a combination of quantitative measures (GIS, gravity models and regression analysis), the authors compare sprawl and its development forms with residential energy consumption by towns to determine whether compactness is suitable for urban warming mitigation and habitat environment quality improvement.

Key Findings:

· The benefits of compactness may be offset by household distance to greenspace and water bodies.

· Designing access to greenspaces and waterbodies to enable local residential use may positively impact urban energy use.

Reference:

Ye, H., He, X., Song, Y., Li, X., Zhang, G., Lin, T., & Xiao, L. (2015). A sustainable urban form: The challenges of compactness from the viewpoint of energy consumption and carbon emission. Energy and Buildings, 93, 90-98.

http://www.sciencedirect.com/science/article/pii/S0378778815001061

Eco-cities and sustainable lifestyles

Aims and method:

Examines if planning and design processes focused on developing sustainable communities result in substantive shifts in resident behaviour. Combining a review of planning and development documents with survey data (convenience sample of approximately 400 residents), and face-to-face interviews (with local officials), the authors evaluated behavioural changes in China’s Sino-Singapore Tianjin Eco- City (SSTEC).

Key Findings:

· Most respondents report moving to the city because they consider it to have a good ecological environment (not because they wish to live a low-impact lifestyle)

· Changes in resident behaviour are mixed. While approximately a quarter report walking more since moving in, private car ownership remains high (63% report owning at least one car) with minimal reduction in trips made by car.

· Energy consumption is reduced principally through improved technology, not lifestyle change.

Reference:

Flynn, A., Yu, L., Feindt, P., & Chen, C. (2016). Eco-cities, governance and sustainable lifestyles: The case of the Sino-Singapore Tianjin Eco-City. Habitat International, 53, 78-86.

http://www.sciencedirect.com/science/article/pii/S0197397515002349