Marshall Flug

Measurement of stream channel habitat using sonar

An efficient and low cost technique using a sonar system was evaluated for describing channel geometry and quantifying inundated area in a large river. The boat-mounted portable sonar equipment was used to record water depths and river width measurements for direct storage on a laptop computer. The field data collected from repeated traverses at a cross-section were evaluated to determine the precision of the system and field technique. Results from validation at two different sites showed average sample standard deviations (S.D.s) of 0.12 m for these complete cross-sections, with coefficient of variations of 10%. Validation using only the mid-channel river cross-section data yields an average sample S.D. of 0.05 m, with a coefficient of variation below 5%, at a stable and gauged river site using only measurements of water depths greater than 0.6 m. Accuracy of the sonar system was evaluated by comparison to traditionally surveyed transect data from a regularly gauged site. We observed an average mean squared deviation of 46.0 cm2, considering only that portion of the cross-section inundated by more than 0.6 m of water. Our procedure proved to be a reliable, accurate, safe, quick, and economic method to record river depths, discharges, bed conditions, and substratum composition necessary for stream habitat studies.

Environmental Resources Analysis System, A Prototype DSS

Since the 1960s, an increase in the public’s environmental ethics, federal species preservation, water quality protection, and interest in free flowing rivers have evolved to the current concern for stewardship and conservation of natural resources. This heightened environmental awareness creates an appetite for data, models, information management, and systematic analysis of multiple scientific disciplines. A good example of this information and analysis need resides in the Green and Yampa Rivers, tributary to the Upper Colorado River. These rivers are home to endangered native fish species including the pikeminnow and razorback sucker. Two dams, Fontenelle and Flaming Gorge, impound the Green River headwaters. The respective reservoirs store water supplies as well as generate hydropower. Conversely, the Yampa River is considered unregulated and encompasses most of Dinosaur National Monument. Recreation is highly regarded on both rivers including fishing, whitewater rafting, and aesthetic values. Vast areas of irrigated agriculture, forestry, and mineral extraction also surround these rivers. To address this information need, we developed a prototype Environmental Resources Analysis System (ERAS) spreadsheet-based decision support system (DSS). ERAS provides access to historic data sets, scientific information, statistical analysis, model outputs, and comparative methods all in a familiar and user-friendly format. This research project demonstrates a simplified decision support system for use by a diverse mix of resource managers, special interest groups, and individuals concerned about the sustainability of the Green and Yampa River ecosystem. Background The damming of Western rivers has led to an altering of the physical, chemical, and biological elements from the natural ecosystem (Collier, et al.1996). These perturbed, regulated river ecosystems have demonstrated impacts on the physical structure of the watershed, river channel, and floodplain; the hydrology and water quality; and the terrestrial, riparian, and aquatic biota (Poff, et al., 1997). Water demands continue to increase as a result of population growth, dwindling ground water supplies, industrial or energy development, snowmaking, and recreation-based instream flow needs. Sustainable use of land-based and aquatic resources must be based on an understanding of how ecosystems are structured and the functional relationships among biotic and abiotic components of the river system (National Research Council, 1992). River exploitation for flood control, hydropower generation, crop irrigation, and water supply has resulted in widespread ecological degradation and loss of biological diversity (The Nature Conservancy, 1996). The consequences of current regulated river management and development have led to declines in abundance of or even extirpation of species, closure of fisheries, groundwater depletions, declines in water quality and availability, and loss of wetlands and