THE 2011 AEESP Education & Research Conference, Held at The University of South Florida (July 10-12)
URBAN FUTURES – SUSTAINABILITY (RESILIENCE) EVALUATION OF WATER INFRASTRUCTURE FA Memon*1, D Butler1, R Farmani1, H. Abdelmeguid1, S. Atkinson1, C. Rogers2, D. Hunt2 1 University of Exeter, United Kingdom 2 University of Birmingham, United Kingdom *CEMPS, Harrison Building, University of Exeter, United Kingdom, EX4 4QF, Phone: 0044 1392 26 4048, Fax: 0044 1392 21 7965, Email:
[email protected] Owing to uncertain future coupled with emerging concerns associated with climate change and population growth/shift to urban areas, a twin track approach of both mitigation and adaptation measures is required to plan, design and operate urban services to maximise resource efficiency, minimise redundency of the available infrastructure (through urban regeneration) and explore sustainbility optimisation options. Sustainability, by default, is a subjective term and its evalution and implementation does require negotiating trade offs between conflicting goals. The incorporation of future influnces must be an integral part of any evalution exercise aimed at achieving long term sustainability aspiration. Within this context, a 4 year muli disciplinary and multi institutional project, Urban Futures, was undertaken with support from the UK Engineering and Physical Scinces Reserach Council. This paper breifly introduces the Urban Future Project and lists the outcome of an extensive exercise to crystalise wide ranging (probable to plausible) urban future scenarios (Part A) and mainly describes the methodology applied to assess the future scenario implications on water infrastructure (Part B). Part A: The high level goal of the Urban Futures project is to test resilliance of today's 'sustainable solutions' and explore strategies and options for infrastructure future proofing. This is addressed through a focused (but integrated) investigation of key urban services (including water and wastewater). The reserach work was organised in 8 distinct work packages. These and interactions between them are outlined in Figure 1.
WP8 WP7
WP1
WP5
WP3
WP6
WP4
Figure 1 Urban future project work packages and interactions
As a function of societal values and the nature of regulatory/policy regimes, four future scenarios have been adopted: Market Forces (MF), Policy Reform (PR), New Sustainability Paradigm (NSP) and Fortress World. The scenarios extraction process, their definitions and interpretations for water related aspects of the project are summarised in Hunt et al (2010).
THE 2011 AEESP Education & Research Conference, Held at The University of South Florida (July 10-12)
Part B: This part describes the methodology, developed to implement urban futures interpretations for water infrastructure, comprising the development of an urban water optioneering tool (UWOT?) and a water distribution network simulation. In order to investigate the impacts of the above mentioned future scenarios and the influnce of currently available (sustainble) technologies on water (demand) consumption patterns and implications for water cycle mangement, UWOT? has been developed. The tool consists of a technology library and a user interface. The library is populated with a wide range of technologies for potable water consupmtion reduction, alternative non potable supply and reuse at different scales (centralised and decentralised) and surface water managment. For each technology, the library also includes information associated with sustainbility indicators (including water saving potential, cost, energy consumption and social acceptability). The tool is coupled with a multi-objective optimisation solver and produces automated optimal composite strategies, their respective sustainbility evaluations and water demand patterns for any of the above mentioned or user defined future scenarios. The resilience, of existing water distribution networks, to fluctauting water demands and urban growth patterns could vary signficantly for different future scenarios. For example in the MF scenario, demand is envisaged to increase signficantly and sections of a network are likely to become vulnerable at satisfying the minimum surplus head requirement. On the other hand, under NSP scenario demand will reduce considerably and therfore water age in the network is likley to incease and in turn could prompt water quality deterioration.
Figure 2 Resilience index relationship with demand mulipliers & rehabilitation investments
To analyse the above mentioned and related operational issues, quantify network resilience to future scenarios and propose optimal network rehabilitation strategies, simulations were carried out using a benchmark network (Anytown). An example simulation output (Figure 2) shows the influence of network rehabilitation investments and water demand multipliers (future scenario combinations) on resilience index (i.e. surplus hydraulic power in the network). The figure suggests that for certain scenarios, even higher investments do not necessarily guarantee improved resilience index. The project, currently in its final stage, is testing the developed methodology using a number of national and international case study sites. Hunt, D. V. L., Farmani, R. Lombardi, D R., Butler, D, and Memon, F.A. (2010). A Sustainability Toolkit For Scenario Based Urban Futures Research Into Water Provision: Methodology - Paper 2, In Sustainable Water Management in Developing Countries – Challenges and Opportunities, UNESCO-DelPHE International Conference on Sustainable Water Management (SWM2010), Jamshoro, Pakistan , 15-17 September 2010, ISBN 0-9539140-4-6, 366-377
