River Science at the U.S. Geological Survey (2007) / Chapter Skim
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4 Priority Areas for USGS River Science
4 Priority Areas for USGS River Science
Pages 70-100
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From page 70... ...
As outlined in Chapter 3, the USGS role should reflect its own mandate and capabilities and build upon its core strengths. The design and activities of a USGS river science initiative should be guided by the overarching goal to provide unbiased, policy-relevant, science-based information to advance understanding and support decision making for the nation's river systems.
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From page 71... ...
conduct a national inventory to survey and map the nation's stream and river systems according to key landscape features that act as determinants of hydrologic, geomorphic, and ecological processes in streams and rivers and (2) develop conceptual and predictive models that could be used to couple surface water, groundwater, geochemistry, and sediment fluxes, and to quantify ecological responses.
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From page 72... ...
, water quality [EPA] , and water quantity [USGS]
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From page 73... ...
. Therefore, to ensure that monitoring information is transferable to all locations of interest, it is important that USGS river science research cover the full range of river settings and processes.
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From page 74... ...
What Are Some Examples on How the USGS Might Do This? Because rivers integrate processes across diverse environments and multiple scales (i.e., the flow regime in rivers depends on the watershed's climate, topography, geology, land cover, and river size)
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From page 75... ...
In the context of USGS river science, developing a comprehensive set of map layers based on key environmental factors would provide a tremendous resource to a number of potential end users; the USGS would not necessarily be compelled to develop a classification system per se. USGS data resources and mapping capability are well suited to the task of developing and implementing this mapping program.
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From page 76... ...
. © 2002 by the American Water Resources Association.
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From page 77... ...
77 PRIORITY AREAS FOR USGS RIVER SCIENCE Source of Flow CD/H CD/L CW/M CW/H CW/L CW/LK CX/M CX/H CX/L CX/LK 0 9 18 27 36 Km Valley Landform CD/L/SS/P/LO/LG CD/L/AL/P/MO/LG CD/L/AL/P/LO/LG CD/L/HS/P/HO/LG CD/L/AL/P/HO/LG CD/L/SS/P/MO/LG 0 0.6 1.2 1.8 2.4 km FIGURE 4-1 Continued
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From page 78... ...
The USGS has a long history of developing quantitative process-based models of both heuristic and real-world hydraulic systems. Suites of publicly available software are used to model a wide range of processes, including runoff in large river basins, flow and sediment transport in rivers and estuaries, and groundwater transport of solutes and pollutants in aquifers.
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From page 79... ...
The network of over 7000 streamflowgaging stations, with standardized and quality-controlled streamflow and waterquality data, contributes to the USGS's development and testing of numerical models of streamflow, sediment transport, nutrient cycling, and ecosystem responses to variations in water-quality constituents, such as dissolved oxygen, temperature, and salinity. A number of USGS researchers are illustrating the strengths and potential applications of integrated multicomponent models.
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From page 80... ...
. In a similar way, the USGS could also play a leadership role in developing a Community River Sediment Transport Model in collaboration with other federal agencies, academic institutions, and private industry, with the goal of adopting and/or developing one or more models for use as scientific tools by the river science community and government agencies responsible for river management.
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From page 81... ...
to management-scale changes in river flow regimes. Recommendation: The USGS should, in cooperation with and sup port of other federal agencies involved in restoration, serve as a leader to evaluate the scientific effectiveness of river restoration approaches to achieve their goals, synthesizing results from past restoration efforts and designing standard protocols for the moni toring and assessment of river restoration projects.
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From page 82... ...
A specific, emerging area of river ecology, called environmental flows, attempts to understand the ecological responses to flow alteration. Environmental flows are broadly defined as those flow levels and patterns (e.g., magnitude, timing, and variability)
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From page 83... ...
Quantitative models relating ecological function to flow regimes will allow natural resource managers and citizens to forecast the impacts of proposed water management decisions. This will enhance the ability to make scientifically informed decisions.
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From page 84... ...
Ecological processes such as primary production, decomposition, and nutrient cycling that support river food webs and contribute to water purification have also been strongly modified by alterations to river flow regimes. All of these problems contribute to a growing concern about the ecological sustainability of our nation's rivers and streams, and society has shown a strong interest in responding through scientifically informed management of our water resources.
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From page 85... ...
present an opportunity to develop coupled hydrologic-ecological models. For example, there are now many large, expensive river restoration projects that are motivated by the recognition that the river flow regime needs to be restored to a more natural condition to improve ecosystem function, such as in the Grand Canyon (NRC, 1996)
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From page 86... ...
and the San Pedro Riparian National Conservation Area." Key research needs include developing groundwater models (to describe how the groundwater system is related to the river and to understand the effects water uses have on the entire system) ; a decision support system (to integrate available information into a computer program that allows decision makers to see the poten tial impact of specific water management scenarios)
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From page 87... ...
Sediment Transport and Geomorphology Recommendation: The USGS should increase its efforts to improve the understanding of sediment transport and river geomorphology in the nation's rivers. By advancing basic research on sediment transport processes, and by developing new technologies for mea suring fluxes of bed load, suspended load, and wash load, the USGS can provide key information and tools to predict channel morpho dynamics, develop methods to mitigate future problems arising from sediment movement, and play a guiding role in multiagency efforts to deal with the increasingly important national sediment challenges.
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From page 88... ...
In the Colorado River downstream of Glen Canyon Dam, the channel is depleted of sediment, resulting in persistent erosion of beaches and sand bars that serve as habitat for threatened and/or endangered native warm water fishes. On the lower Mississippi, lack of sediment transport into the floodplain has resulted in the continuous degradation of the Mississippi Delta, decimating marsh lands that are the main source of natural protection against the devastating effects of hurricanes such as Katrina.
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From page 89... ...
The Sacramento-San Joaquin Delta is another good example of a sediment-starved system where management decisions would benefit greatly from basic knowledge of sediment transport. This region has many levees that were built by early settlers that are now privately owned and unmaintained.
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From page 90... ...
300-200 More than 6000 FIGURE 4-2 Map of suspended sediment concentrations in selected river basins within the continental United States and estimated sediment discharges for some of the country's major rivers. SOURCE: Meade and Parker (1985)
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From page 91... ...
to synthesize and integrate the sediment transport work of federal and state agencies with sediment-related programs and provide comprehensive analysis to support national applications. While other agencies (U.S.
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From page 92... ...
To do this, better tools and methods need to be developed to evaluate spatial and temporal discontinuities in streamflow and sediment transport at a range of scales. This information is essential for evaluating land-based water fluxes, as well as sediment and carbon fluxes to the ocean.
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From page 93... ...
In addition to spatial variations in sedimentation across the nation, sedimentation rates also change with time. Figure 4-3 shows a temporal perspective of sediment transport in the Mississippi River basin.
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From page 94... ...
. Sediment transport technology needs to be advanced by the USGS in partnership with other federal agencies and universities to assess sediment fluxes in rivers, deltas, and estuaries (http://water.usgs.gov/osw/techniques/sedtech21/)
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From page 95... ...
Also stage modifications in regulated river systems have altered stream groundwater exchange processes, an issue that is difficult to evaluate because preregulation data are often missing. Additionally, urbanization of river systems that requires channel modi FIGURE 4-4 Average base flow fraction of streamflow attributed to groundwater.
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From page 96... ...
Hyporheic exchange processes also underpin other stream and riparian functions including sediment transport and deposition, water and quality, and water temperature, which all relate to the quality of the ecological habitat. Such hyporheic issues are not just limited to the dry western states like they once were.
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From page 97... ...
The capacity of river systems to affect water quality by processing pollutants such as nutrients has enormous application to a nationwide problem of the unsuitability of large numbers of waterbodies for their designated uses. The Clean Water Act is a major driver for research in this area, through requiring estimates of total maximum daily loads (TMDLs)
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From page 98... ...
95° Shingobee Lake 92° Shingobee Fern River MINNESOTA Bemidji Watershed boundary Hubbard Cass 47° KILOMETER Duluth County County MILE Walker IRI Watershed Park Rapids Mississippi River Williams Lake St. Paul Minneapolis Minnesota River 44° Location of the USGS Shingobee Headwaters Aquatic Ecosystems Project (SHAEP)
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From page 99... ...
, the USGS gage network has been critical to providing the fundamental data supporting the emerging field of hydroecology in the last decade. For example, regional flow regime classifications have been constructed using streamflow data from the USGS National Streamflow Information Program.
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From page 100... ...
The USGS should strengthen its research efforts in sediment transport and geomorphology on our nation's rivers to address the increasing problems due to alterations in river flows and channel morphology.
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