David Purkey
Senior Scientist
Davis, CA
dpurkey@sei-us.org
skype: dpurkey
+1 (530) 753-3035 x1#
David Purkey runs the Northern California office of SEI-US and is actively involved in the SEI Water and Sanitation Program in the the United States and globally. Much of his work centers around the development, dissemination and application of SEI's Water Evaluation and Planning (WEAP) system. His research interests include understanding the potential impacts of and adaptation to climate change in the water sector and aquatic ecosystems, integrated water resources management that focuses on linking the management of surface water and groundwater to meet a broad spectrum of objectives, and equitable management of transboundary water resources. David and his team are experienced in applying a range of hydrologic, hydraulic, and planning models in setting as diversion as California, the US-Mexico border, the Great Lakes, and West and Southern Africa. David received his Ph.D. in hydrology from the University of California, Davis in 1998.
Recent Publications by David Purkey
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Scenario-based water resources planning for utilities in the Lake Victoria regionPhysics and Chemistry of the Earth, Parts A/B/C, in press; available online 16 March 2013 Author(s): Mehta, V. ; Purkey, D. ; Aslam, O.; Dale, L.; Miller, N.Year: 2013 Research Area(s): Water Resources Description: This article describes the development of water resources models for three East African towns to investigate climate, infrastructure and demographic scenarios. Urban areas in the Lake Victoria region are experiencing the highest growth rates in Africa. As efforts to meet increasing demand accelerate, integrated water resources management (IWRM) tools provide opportunities for utilities and other stakeholders to develop a planning framework comprehensive enough to include short-term (e.g. land-use change), as well as longer-term (e.g. climate change) scenarios. This paper presents IWRM models built using the Water Evaluation And Planning (WEAP) decision support system, for three towns in the Lake Victoria region: Bukoba (Tanzania), Masaka (Uganda), and Kisii (Kenya).More information External Link |
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Irrigation demand and supply, given projections of climate and land-use change, in Yolo County, CaliforniaAgricultural Water Management 117, 70-82 Author(s): Mehta, V. ; Joyce, B. ; Purkey, D. ; Haden, V.R.; Jackson, L.E.Year: 2013 Research Area(s): Water Resources Description: This article assesses the potential effects of climate change and adaptive management on irrigation water supply in the Cache Creek watershed in California. The authors built a model using the Water Evaluation And Planning (WEAP) system, and calibrated it using historical data (1971-2000) on streamflow, irrigation deliveries, and reservoir operations. Results show irrigation demand increasing by 26% and 32% under B1 and A2 baseline climate scenarios respectively in the latter part of the century. Increases in demand from climate change alone exceed applied water reductions from changing cropping patterns by an order of magnitude. Maximum applied water savings occur by combining a diversified water-efficient cropping pattern with irrigation technology improvements.More information External Link |
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Un Marco de Apoyo a la Toma de Decisiones para Adaptación al Cambio ClimáticoFinal report: Modelling the Role of Páramo in Hydrology under a Climate Change Scenario Author(s): Flores, F. ; Escobar, M. ; Purkey, D. ; Forni, L. ; Segura, H.Year: 2012 Research Area(s): Water Resources Description: Este informe describe un proceso para el apoyo a la toma de decisiones para adaptación al cambio climático en el sector de agua que combina distintas herramientas para analizar opciones bajo incertidumbre. Nuestro proceso combina el marco XLRM de la RAND Corp., el sistema Ensamble para automatizar la corrida de modelos y la visualización de datos con Tableau, utilizados juntos bajo un marco analítico de toma de decisiones robusta. Nuestro marco de apoyo les permite a los planeadores (1) adquirir y/o desarrollar datos sobre el vínculo entre condiciones potenciales futuras de clima y riesgo; (2) evaluar el impacto de diferentes escenarios climáticos en el desempeño y los resultados de distintas medidas; y (3) evaluar estrategias de adaptación frente a riesgo asociados con el clima. Es importante anotar que este proceso también ayuda a los administradores de recursos hídricos a responder a otras incertidumbres no relacionadas con el cambio climático (cambios demográficos, cambio en regulaciones, etc.).More information Download PDF |
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A Regional Water Resource Planning Model to Explore the Water-Energy Nexus in the Southeastern United StatesePoster GC21C-0977, American Geophysical Union Fall Meeting, San Francisco, 3-7 December 2012 Author(s): Flores, F. ; Yates, D. ; Purkey, D.Year: 2012 Research Area(s): Water Resources Description: The power sector withdraws substantial cooling water for electricity generation across the United States and is thus heavily dependent on available water resources. Subsequently, any changes in water supply undermine the reliability of power generation. As a case study for exploration of these issues, we built a model of surface water availability, stream water temperature implications, and different development pathways under current and future conditions in two basins: the Apalachicola-Chattahoochee-Flint (ACF) Basin and the Appaloosa-Coosa-Tennessee Basin (ACT), using the Water Evaluation and Planning (WEAP) system. The model also represents different energy strategies through scenarios derived from the National Renewable Energy Laboratory (NREL) Regional Energy Deployment System (ReEDS) analysis that is being conducted independently, and for the entire United States. Other development pathways are explored include changes in population growth projections and agriculture water demands.External Link |
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Water Management Adaptations to Prevent Loss of Spring-Run Chinook Salmon in California under Climate ChangeJournal of Water Resources Planning and Management 138(5), 465-478 Author(s): Thompson, L.C. ; Escobar, M. ; Purkey, D. ; Yates, D. ; Mosser, C.M.; Moyle, P.B.Year: 2012 Research Area(s): Water Resources Description: Spring-run Chinook salmon (Oncorhynchus tshawytscha) are particularly vulnerable to climate change because adults over-summer in freshwater streams before spawning in autumn. In this study, the authors examined streamflow and water temperature regimes that could lead to long-term reductions in spring-run Chinook salmon (SRCS) in a California stream and evaluated management adaptations to ameliorate these impacts. For all climate scenarios and model combinations, the model found increased adult summer thermal mortality and population declines. Of management adaptations tested, only ceasing water diversion for power production from the summer holding reach resulted in cooler water temperatures, more adults surviving to spawn, and extended population survival time, albeit with a significant loss of power production.More information External Link |