The Mendenhall Research Fellowship Program provides an opportunity for postdoctoral fellows to conduct concentrated research in association with USGS professional staff, as well as with staff in sister agencies. Mendenhall Fellows are appointed to the USGS for two years and receive full salary and benefits at the GS-12 level. Detailed descriptions of each research opportunity and information about how to apply are available at < http://geology.usgs.gov/postdoc/>. The application deadline is February 21, 2012.
21. Hydrology, Geomorphology, and Riparian Habitat in the Upper and Middle Verde River The Verde River basin in central Arizona is a prime example of an area experiencing a severe and growing problem that will become increasingly critical for Arizona and the Nation: the need to balance the water supply needs of a growing population and vibrant economy against the water supply required to maintain an acceptable state of ecological health in the riparian environment. Numerous stakeholders, including local governments, State agencies, municipal water providers, environmental groups, and citizen work groups, have participated in attempting to guide the future of water resources in the Verde River basin, at times with conflicting views and goals. The city of Prescott, Prescott Valley, and Chino Valley reside on a high-elevation plateau above the origin of the perennial reach of the Verde River. Below the populated areas, the river occupies a narrow, scenic, and remote valley before entering the broad Verde Valley with the cities of Clarkdale and Cottonwood. All of these population centers have experienced an increase in population and demand for water in recent decades that has led to increases in groundwater withdrawals, and the prospect for further increases in groundwater withdrawals in the future, which can potentially decrease the base flow in the Verde River. Concern about the impacts of pumping, compounded by uncertainties related to climate variability, has led to increased interest in the large-scale hydrologic system, large and local scale water budgets, and the relation between aquifer withdrawals, streamflow in the Verde River, and riparian habitat. The USGS has been working in the Verde River Basin to provide the data and interpretation required to make informed decisions regarding the hydrologic system. An ongoing project is examining the relation between hydrology and riparian habitat; we seek a Mendenhall Fellow to study a key link between those two elements: the geomorphic structure, history, and evolution of the river. The experience of the Research Advisors and discussions with colleagues working on the Verde River has made plain the importance of the geomorphic link between streamflow and ecological processes. The Verde River is home to in-stream populations inextricably tied to specific sediment and flow regimes. Yet there remain many unanswered questions regarding storage and residence times of fine sediment; the source of wash-load fines that persist at low flows; the sources of gravels; the frequency, magnitude, and dependence on streamflow of mobilization of gravels; the effect of Sullivan Dam (an unregulated dam located above the perennial reach) on sediment sources and stream evolution; as well as the future development of flood plains. We anticipate that the research focus would involve a combination of these topics in order to quantify geomorphic settings (e.g. pool, riffle, run) as a habitat component and relate their formation and persistence to streamflow. An abundance of related information from research by scientists at universities, other federal, state, and local agencies, and the USGS, provides a foundation for new work in the Verde basin. For example, a recently completed regional groundwater model by the USGS (Pool and others, 2011) that includes the Verde basin has recently been completed and has been used to assess the general effects of groundwater pumping on the timing and magnitude of base flow responses in the Verde River (Leake and Pool, 2010). The model could be further used to assess in greater detail the base flow in the Verde River and its tributaries in response to changes in recharge or to groundwater withdrawal. In addition, the USGS has published a report describing the hydrogeology of the upper and middle Verde basins (Blasch and others, 2006). Extensive mapping of valley alluvium and the historical geomorphic evolution of the river has been published by the Arizona Geological Survey (Pearthree, 2008; Cook and others, 2010). One-dimensional flow modeling and monitoring of stream diversions in parts of the study area has clarified important streamflow processes (Ross and others, 2010). An ongoing project conducted by the RAs is examining the connection between streamflow and in-stream habitat. References Blasch, K.W., Hoffmann, J.P., Graser, L.F., Bryson, J.R., and Flint, A.L., 2006, Hydrogeology of the upper and middle Verde River watersheds, central Arizona: U.S. Geological Survey Scientific Investigations Report 2005?5198,102 p., 3 plates. Cook, J.P, Pearthree, P.A., Onken, J.A., Youberg, A.,and Bigio, E.R., 2010, Mapping of the Holocene River alluvium along the Verde River, central Arizona, Report to the Adjudication and Technical Support Unit Surface Water Division Arizona Department of Water Resources, Arizona Geological Survey. Leake, S.A., and Pool, D.R., 2010, Simulated effects of groundwater pumping and artificial recharge on surface-water resources and riparian vegetation in the Verde Valley sub-basin, Central Arizona: U.S. Geological Survey Scientific Investigations Report 2010-5147, 18 p. Pearthree, P.A., 2008, Fluvial geomorphology and flood history of the Verde River, 2008, in Haney, J.A., Turner, D.S., Springer, A.E., Stromberg, J.C., Stevens, L.E., Pearthree, P.A., and Supplee, V., 2008, Ecological implications of Verde River flows: A report by the Arizona Water Institute, The Nature Conservancy, and the Verde River Basin Partnership, viii + 114 pages. Pool, D.R., Blasch, K.W., Callegary, J.B., Leake, S.A., and Graser, L.F., 2011, Regional groundwater-flow model of the Redwall-Muav, Coconino, and alluvial basin aquifer systems of northern and central Arizona: U.S. Geological Survey Scientific Investigations Report 2010-5180, v. 1.1, 101 p. (http://pubs.usgs.gov/sir/2010/5180/) Ross, R., Springer, A., and Schlinger, C., 2010, Verde Valley Hydraulic Model Project, report to Yavapai County Water Advisory Committee. Proposed Duty Station: Tucson, AZ Areas of Ph.D.: Geology, civil engineering, ecology, geography, or other related field with relevant coursework and thesis emphasis (candidates holding a Ph.D. in other disciplines but with knowledge and skills relevant to the Research Opportunity may be considered) Qualifications: The position requires a quantitative background, understanding of fluvial processes, including sediment transport and channel hydraulics, and the ability to conduct field research, and a desire to relate geomorphic processes to biological processes. Understanding of surface-water statistics would also be helpful. In addition, applicants must meet one of the following qualifications: Research Hydrologist, Research Ecologist (This type of research is performed by those who have backgrounds for the occupations stated above. However, other titles may be applicable depending on the applicant's background, education, and research proposal. The final classification of the position will be made by the Human Resources specialist.) Research Advisors: Stephen Wiele (520) 670-6671 x277, smwi...@usgs.gov; Anne Brasher (435) 259-3866, abras...@usgs.gov Human Resources Office Contact: Candace Azevedo, (916) 278-9393, caazev...@usgs.gov
