Daniel Caparros-Midwood, Richard Dawson & Stuart Barr, Newcastle University, Newcastle upon Tyne, UK
Presentation Title: Optimized spatial planning against sustainability objectives
To explore the trade-offs between multiple, often conflicting sustainability objectives within cities, a spatial optimization framework was developed that can identify spatial development strategies that perform well or are the best for an individual or multiple sets of sustainability objectives. The methodology entails iteratively investigating a wide range of spatial set-ups of development against their objectives before converging on optimal spatial patterns. To explore the implications of future residential development choices on key sustainability objectives identified by the local planning authority, the method was applied to a case study in the northeast of England, namely: (1) Minimizing risk from heat waves; (2) Minimizing risk from flooding; (3) Minimizing the distance of new development to the current central business district to minimize travel costs; (4) Minimizing urban sprawl to prevent increased travel costs; and, (5) Preventing the development of green-space. Spatial strategies were identified that were shown to be best performing (Pareto optimal) across one or more objectives. The results provided urban planners with a range of spatial development planning options that satisfy key objectives. Coupled with further qualitative consideration of issues not amenable to quantified assessment, this approach could provide a powerful mechanism for developing more sustainable urban development plans.
Key Lessons Learned
Urban sustainable development under multiple drivers and pressures (i.e., social, economic and climate change) requires a new process to consider and alleviate conflicts, which occur between sustainability initiatives. There is the need for an analytical appreciation of how conflicts interact and how best to mitigate their impacts whilst planning future sustainable development. For example: experience has shown sustainability interventions in one sector can have undesirable impacts on other sectors, which affects overall sustainability. The most illustrative of this has been the process of urban intensification with the intention of mitigating transport emissions by encouraging the use of public transport and discouraging private transport. However, as mitigation strategies have failed to halt climate change in the short-term, this compact urban form exacerbates many of these climate related hazards such as heat waves and floods.
Policy/Practice Implications of Research
This research has demonstrated the potential to act as a decision support tool to alleviate conflicts between sustainability objectives during urban spatial planning. Through investigating development patterns, a spatial optimization framework can converge on optimal setups of development and provide urban planners with robust spatial development plans, which with further qualitative analysis can directly inform final planning decisions.
The work provides valuable knowledge to planners by pointing towards trends of development. Results demonstrate particular patterns of development which could be mimicked as well as highlighting locales in the study area, which are more ideal for the location of development.
Knowledge Gaps and Needs
There is a need for integrated modelling of urban systems as differing sectors affect one another. Treating separate infrastructure individually can lead to maladaptation as interactions are ignored, highlighting the need for modelling over multiple infrastructure sectors.
There is a need for further modelling of the effect of types of development, e.g., in risk modelling, more sophisticated urban heat island modelling based on the layout and design of buildings as well as models of how surface run off is affected by different developments.