Abstract Urbanization and competing water demand, as well as rising temperatures and changing weather patterns, are manifesting as gradual processes that increasingly challenge urban water supply security. Cities are also threatened by acute risks arising at the intersection of aging infrastructure, entrenched institutions, and the increasing occurrence of extreme weather events. To better understand these multi-layered, interacting challenges of providing urban water supply for all, while being prepared to deal with recurring shocks, we present an integrated analysis of water supply security in New York City and its resilience to acute shocks and chronic disturbances. We apply a revised version of a recently developed, quantitative framework (‘Capital Portfolio Approach’, CPA) that takes a social-ecological-technological systems perspective to assess urban water supply security as the performance of water services at the household scale. Using the parameters of the CPA as input, we use a coupled systems dynamics model to investigate the dynamics of services in response to shocks—under current conditions and in a scenario of increasing shock occurrence and a loss of system robustness. We find water supply security to be high and current response to shocks to be resilient thanks to past shock experiences. However, we identify a number of risks and vulnerability issues that, if unaddressed, might significantly impact the city’s water services in the mid-term future. Our findings have relevance to cities around the world, and raise questions for research about how security and resilience can and should be maintained in the future.
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Resilience Dynamics of Urban Water Supply Security and Potential of Tipping Points
Cities are the drivers of socioeconomic innovation and are also forced to address the accelerating risk of failure in providing essential services such as water supply today and in the future. Here, we investigate the resilience of urban water supply security, which is defined in terms of the services that citizens receive. The resilience of services is determined by the availability and robustness of critical system elements or “capitals” (water resources, infrastructure, finances, management efficacy, and community adaptation). We translate quantitative information about this portfolio of capitals from seven contrasting cities on four continents into parameters of a coupled system dynamics model. Water services are disrupted by recurring stochastic shocks, and we simulate the dynamics of impact and recovery cycles. Resilience emerges under various constraints, expressed in terms of each city's capital portfolio. Systematic assessment of the parameter space produces the urban water resilience landscape, and we determine the position of each city along a continuous gradient from water insecure and nonresilient to secure and resilient systems. In several cities stochastic disturbance regimes challenge steady‐state conditions and drive system collapse. While water insecure and nonresilient cities risk being pushed into a poverty trap, cities which have developed excess capitals risk being trapped in rigidity and crossing a tipping point from high to low services and collapse. Where public services are insufficient, community adaptation improves water security and resilience to varying degrees. Our results highlight the need for resilience thinking in the governance of urban water systems under global change pressures.
more » « less- NSF-PAR ID:
- 10459264
- Publisher / Repository:
- DOI PREFIX: 10.1029
- Date Published:
- Journal Name:
- Earth's Future
- Volume:
- 7
- Issue:
- 10
- ISSN:
- 2328-4277
- Page Range / eLocation ID:
- p. 1167-1191
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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