TY - JOUR
T1 - Water Planning Under Climatic Uncertainty in Phoenix
T2 - Why We Need a New Paradigm
AU - Gober, Patricia
AU - Kirkwood, Craig W.
AU - Balling, Robert
AU - Ellis, Andrew W.
AU - Deitrick, Stephanie
N1 - Funding Information:
This material is based on work supported by the National Science Foundation under Grant SES-0345945, Decision Center for a Desert City. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation. The authors wish to acknowledge Barbara Trapido-Lurie for graphics support, Sally Wittlinger for editorial help, Michael Tschudi and David Sampson for running WaterSim under multiple future scenarios and Timothy Lant for running the sensitivity analysis.
PY - 2010/4
Y1 - 2010/4
N2 - The uncertainties associated with global climate models pose substantial hurdles for urban water planning. Despite growing consensus among climatologists that the American Southwest is headed for a warmer and drier future, water planners in metropolitan Phoenix and elsewhere are reluctant to consider long-term climate change as a significant factor in increased risk of future water scarcity. A new paradigm for climate research and water planning is needed-one that is based on an assumption of uncertainty and a vision of multiple plausible futures, managing risk, and adaptive behaviors. To this end, we downscaled global climate models from the Intergovernmental Panel on Climate Change Third and Fourth Assessment Reports for the watersheds north of Phoenix and estimated changes in runoff using a hydrological model. Results then were used as inputs to WaterSim, an integrated simulation model of water supply and demand in Phoenix. The model simulated "what if" scenarios under varying policy decisions and future climates. Results of simulation experiments suggest that (1) current levels of per capita water consumption cannot be supported without unsustainable groundwater use under most climate model scenarios, (2) feasible reductions in residential water consumption allow the region to weather the most pessimistic of the climate projections, (3) delaying action reduces long-term sustainability of the groundwater resource under some climate scenarios, and (4) adaptive policy with appropriate monitoring to track groundwater provides warning that the need for use restrictions is approaching and avoids the need for drastic, ad hoc actions.
AB - The uncertainties associated with global climate models pose substantial hurdles for urban water planning. Despite growing consensus among climatologists that the American Southwest is headed for a warmer and drier future, water planners in metropolitan Phoenix and elsewhere are reluctant to consider long-term climate change as a significant factor in increased risk of future water scarcity. A new paradigm for climate research and water planning is needed-one that is based on an assumption of uncertainty and a vision of multiple plausible futures, managing risk, and adaptive behaviors. To this end, we downscaled global climate models from the Intergovernmental Panel on Climate Change Third and Fourth Assessment Reports for the watersheds north of Phoenix and estimated changes in runoff using a hydrological model. Results then were used as inputs to WaterSim, an integrated simulation model of water supply and demand in Phoenix. The model simulated "what if" scenarios under varying policy decisions and future climates. Results of simulation experiments suggest that (1) current levels of per capita water consumption cannot be supported without unsustainable groundwater use under most climate model scenarios, (2) feasible reductions in residential water consumption allow the region to weather the most pessimistic of the climate projections, (3) delaying action reduces long-term sustainability of the groundwater resource under some climate scenarios, and (4) adaptive policy with appropriate monitoring to track groundwater provides warning that the need for use restrictions is approaching and avoids the need for drastic, ad hoc actions.
KW - Climate change
KW - Decision making under uncertainty
KW - Planning paradigm
KW - Simulation modeling
KW - Water resource management
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U2 - 10.1080/00045601003595420
DO - 10.1080/00045601003595420
M3 - Article
AN - SCOPUS:77951231095
SN - 0004-5608
VL - 100
SP - 356
EP - 372
JO - Annals of the Association of American Geographers
JF - Annals of the Association of American Geographers
IS - 2
ER -