HR: 13:55h
AN: H23G-02 INVITED     [Abstracts]
TI: An Emerging Role for Geophysics in Watershed Hydrologic Investigations
AU: * Knight, R
EM: rknight@pangea.stanford.edu
AF: Department of Geophysics, Stanford University, Stanford, CA 94305-2215 United States
AU: Robinson, D
EM: darobinson@cc.usu.edu
AF: Department of Geophysics, Stanford University, Stanford, CA 94305-2215 United States
AB: There is growing recognition of the challenges we face, in many parts of the world, in finding and maintaining clean sources of water for human consumption and agricultural use, while balancing the needs of the natural world. Watershed hydrologic investigations can be used to develop an improved understanding of the controls on the quantity, movement and quality of water, thus enhancing our ability to better protect and manage our water resources. Geophysical methods can play a central role in these investigations. CUAHSI (Consortium of Universities for the Advancement of Hydrologic Sciences) is developing, with the support of the National Science Foundation, a Hydrologic Measurement Facility (HMF), which contains a Geophysics Module. Through the HMF-Geophysics Module our objective is to determine how best to utilize geophysical instrumentation and engage geophysical expertise in addressing key challenges in watershed-scale characterization. We approach the development of HMF-Geophysics with the following questions: 1) What are the parameters that need to be measured in order to adequately describe the quantity, movement and quality of water, and at what spatial and temporal scale do these parameters need to be measured? 2) What can we measure with our geophysical instruments and methodologies, and what are the relevant spatial and temporal scales? 3) Given the answers to 1) and 2) above, what can we do today with geophysics that integrates with hydrological monitoring and modeling approaches, and provides a significant advancement over other forms of measurement? 4) What are the critical research needs in advancing the use of geophysics for watershed hydrologic investigations? When we consider the state-of-the-science in the use of geophysics for all near-surface applications, we identify four cross-cutting areas of research activity that complement the goals of HMF-Geophysics. One area of research is focused on improving the accuracy of our estimates of hydrologic properties from geophysical data. An assessment of the impact of spatial resolution and heterogeneity on property estimates has led to new ideas about site-specific methods that can be used to better constrain the relationship between geophysical and hydrologic properties. A second area of research involves quantifying spatial heterogeneity with geophysical images. Theoretical and field studies of the scale-dependent nature of both natural systems and geophysical images are allowing us to find ways of extracting information about the correlation structure of the subsurface from geophysical data. This leads to a third active area of research, which is improving the quality of subsurface images. New forms of sensors and new approaches to the processing and inversion of data are providing dramatic improvements in our imaging abilities. The fourth area of research seeks to find new forms of geophysical measurement that are sensitive to the biogeochemical processes that can impact water quality. Recent studies have shown a close link between biogeochemical processes and the electrical properties and nuclear magnetic resonance response of geological materials. Through HMF-Geophysics our goal is to build on these active areas of research to advance the use of geophysical methods in developing new strategies for the improved protection and management of our water resources.
DE: 0994 Instruments and techniques
DE: 1879 Watershed
DE: 1894 Instruments and techniques: modeling
DE: 1895 Instruments and techniques: monitoring
SC: Hydrology [H]
MN: Fall Meeting 2005