Watershed Research in the U.S. Geological Survey (1997) / Chapter Skim
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SCIENTIFIC OPPORTUNITIES FOR USGS
SCIENTIFIC OPPORTUNITIES FOR USGS
Pages 33-69
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From page 33... ...
Thus, future watershed research programs at the USGS must focus on scientific topics having direct relevance to current and future water policy 33
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From page 34... ...
Thus, protection and improvement of the quality of ground water and surface water in the United States, particularly the protection of drinking water supplies, continue to be high priorities. Protection of surface water quality has long been a concern of most federal and state regulatory agencies and involves all components of the surface water budget.
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From page 35... ...
ng Drought Slope stability Hydrologic responses as indicators of climatic change Hydrologic feedback to climatic change Global carbon cycling Aquatic habitats in streams Natural flow regimes Wetlands function and restoration Structural versus restorative approaches
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From page 36... ...
Geological Survey agricultural watersheds include streambank erosion controls, improved storage and disposal of animal wastes, improved agricultural tillage practices, and water control structures; local landowners and regulatory agencies share the expenses of implementing these practices. A major problem with many such watershed management programs is that the water quality benefits resulting from the management practice changes are often difficult to predict or assess using current models and field techniques.
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From page 37... ...
Even though atrazine use in many parts of the Midwest currently is being banned or sharply reduced, it is likely that atrazine and its metabolites could persist at low concentrations in watersheds for many years. As a result, contaminant levels in ground water and surface water might increase as atrazine leaches downward from the soil zone.
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From page 38... ...
38 Watershec/ Research in the U.S. Geological Survey
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From page 39... ...
Many scientific opportunities exist for water quality monitoring and research in urban and suburban watersheds. Urban settings can deliver a broad mix of potential contaminants to surface water and ground water, and hydraulic residence times are commonly short, offering little opportunity for degradation or sorption of contaminants prior to downstream discharge.
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From page 40... ...
Best management practices for urban watersheds are still evolving. Predictions of urban storm water quality based on models developed in rural or undeveloped areas are prone to fai I u ret Because of its established record of achievement in data collection and assessing major point and nonpoint sources of nutrient flux in U.S.
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From page 41... ...
As the nation's population continues to grow, demands for additional water for potable and industrial uses will also increase, and there will be increasing pressure to find and develop new sources of ground water and surface water while maintaining water quality and quantity. On a global basis, it is estimated that society's ability to appropriate runoffwill increase by 10 percent in the next 30 years, while the population will increase by 45 percent in the same time period (Poster et al., 19961.
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From page 42... ...
More research is needed to evaluate the long-term effectiveness of such projects in sustaining local and regional ground water withdrawals and their short- and long-term effects on water quality, both locally and throughout watersheds. It is also important to evaluate water quality issues associated with artificial recharge practices.
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From page 43... ...
Leakage from subsurface disposal systems also can follow similar pathways to streams. Knowledge of the fate of substances as they move through subsurface environments to surface waters is important not only in unclerstanding the nature of contamination but also in designing management programs.
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From page 44... ...
Watershed research provides one obvious framework in which to collect such data. Basin-wide water management requires information about current land use.
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From page 45... ...
The result of wetlands drainage often is a complete change in almost all hydrologic properties of the landscape, including such parameters as drainage patterns, slope, vegetation, surface roughness, impermeable area, and soil compaction. The watershed response to such alterations can include increased flood peaks and flood frequency, increased bank erosion, degradation of surface water quality, and reduced ground water recharge.
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From page 46... ...
Geological Survey Total / i_ Nitrogen ° on Potash Phosphorous 1960 1965 1970 1975 1980 1985 1990 1995 Year FIGURE 4.1 Commercial fertilizer applied to cropland in the United States, 1960-1992. Source: Lin et al.
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From page 47... ...
is evidence that individual conventional septic systems contribute to ground water contamination (Robertson et al., 19911. What is the long-term effect of suburban development on the quantity and quality of ground water and surface water?
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From page 48... ...
Or do the floods signal a significant change in hydrologic response related either to climatic change or long-term anthropogenic changes in watersheds throughout the upper Midwest? Watershed studies at various scales can help address these q uestions.
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From page 49... ...
The flooding also caused ground water contamination in areas where flood waters overtopped well casings or ground water recharge areas. There was also significant destruction of wildlife habitat in the flooded areas, some of which were inundated for weeks.
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Sinkhole development also can contribute significantly to ground water contamination, the sinkholes acting as conduits for surface waters to enter ground water systems with little or no attenuation of contaminant loads. Many human activities can induce or accelerate sinkhole formation.
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From page 51... ...
Most important is the determination of how hydrologic, geochemica~, and geomorphological processes respond to shorter-term variations and longer-term changes in climatic conditions. High-resolution, event-based sampling within watersheds provides the basis for improved modeling of flowpaths and streamflow generation, weathering, chemical transport, and water quality genesis processes (Lins, 19941.
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From page 52... ...
The National Research Counci I (1 994b) stated recently that "unti I the current global carbon budget can be balanced, there is little hope of predicting the future changes in atmospheric CO2 concentration and, therefore, the radiative properties oftheatmospherethatwill determinefuture climatic changes." The NRC report outlined a number of activities for deriving a more complete accounting of the global carbon budget.
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Scientific Opportunities for USGS 53
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From page 54... ...
Aquatic Habitat Alteration and Restoration One of the most significant contributions of watershed planning in the 1990s is the prominent role given to relationships among land use, water resources, ecological systems, and sustainable development. While cases of watershed planning in the 1 990s cited by the EPA tended to highlight the flux of either sediments, nutrients, pesticides, or heavy metals from land-disturbing activities, they also point out the linkage between water quality and aquatic organisms and ecosystems.
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From page 55... ...
. Five factors affect overall water resource integrity energy source, water quality, habitat quality, flow regime, and biotic interactions (Rankin, 1996; Karr, 1996~.
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estimates that approximately 1.7 million hectares of lakes is degraded, primarily due to siltation, anywhere from 5 to 70 percent of the approximately 5.1 million river kilometers in this country have been channelized, and approximately 50 percent of the nation's wetlands have been lost over the last 200 years. Most states have not yet fully recognized the importance of habitat alterations when assessing water quality improvements.
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From page 57... ...
Restoration of contaminated or damaged hydrologic regimes and associated ecosystems to more natural conditions has become an important public policy goal in many parts of the United States. For example, restoration of wetlands environments that were previously drained or filled is now seen as important for habitat protection, biodiversity, flood control, water quality maintenance, and a host of other objectives.
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From page 58... ...
I n each of the fou r areas mentioned above large watersheds, urban watersheds, watershed restoration, erosion, and sedimentation- the USGS could play a pivotal role in the development of a knowledge base for effective watershed management. The ingredients of an effective watershed research program to address the interrelated areas identified in this study include (1)
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program. NAWQA is an ambitious program that seeks to evaluate the status of the nation's water quality (NRC, 1990~.
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60 Watershed Research in the U.S. Geological Survey
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Scientific Opportunities for USGS 61 As mentioned above, pieces of the ingredients for a program on "large-watershed" research already exist within the USGS. There are indications that integration of these ingredients is taking place on a selected basis.
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From page 62... ...
Although many social and economic benefits have been realized from these human activities, some areas have experienced the unintentional consequences of exaggerated flood and drought, water quality degradation, reduced ground water recharge, and habitat impairment. In response, watershed restoration a move to recreate some of the predisturbance hydrologic processes and landscape features- has been advocated as the best means to add ress problems of concern.
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Scientific Opportunities for USGS 63
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From page 64... ...
Building on past strengths and this new opportunity, the USGS should advance the science of whole-watershed restoration in four critical areas (1) improvements in the ability to understand relationships among watershed hyclrology, water quality, and habitat; (2)
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From page 65... ...
Work on urban hydrology has been somewhat more scattered, perhaps because there is no agency responsible for determining the effects of urban and suburban land use changes. Because of this fragmentation, a concerted effort by the USGS to develop more systematic i nformation related to hydrologic changes in response to suburban and urban development should be considered.
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From page 66... ...
Special consideration should be given to urban watersheds where improved knowledge of sediment budgets may be of critical importance in understanding the effects of development on water qualityand channel stability. An excellentexampleofwhat can tee done is the USGS work in Puerto Rico (see Box 4.5)
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Scientific Opportunities for USGS 67
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From page 68... ...
I n the area of watershed management, effective uti I ization of research results associated with sediment transport requires that the USGS pursue coordination with agencies charged with managing water resources. Clearly, the USGS is aware of this need, as recently demonstrated in the controlled flood on the Colorado River below Glen Canyon Dam.
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From page 69... ...
Through minor extensions to its existing efforts in sediment transport mechanics and modeling, the potential exists for the USGS to enhance significantly the ARS program as well as other USDA programs.
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