Watershed Research in the U.S. Geological Survey (1997) / Chapter Skim
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SCIENTIFIC RATIONALE FOR WATERSHED RESEARCH
SCIENTIFIC RATIONALE FOR WATERSHED RESEARCH
Pages 20-32
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From page 20... ...
can be studiecl in the laboratory under carefully controlled conditions, the partitioning of rainfall into interception, infiltration, direct surface runoff, evaporation, and ground water recharge, taking into account the natural temporal ancl spatial variability of rai neat I and sol I and vegetative characteristics, can be observed i n a meaningful way only at the watershed scale. Scientists ancl laypersons alike are usually quite comfortable with the notion of laboratory research, but watershed research often has been viewed as collecting data for data's sake, with little scientific content.
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From page 21... ...
material. The formal models generally consist of mathematical descriptions of rea~-wor~d phenomena, whereas material models, including iconic or"~ook-atike" and analog moclels, are real systems that either closely resemble the prototype or have the same mathematical representations.
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From page 22... ...
To obtain numerical solutions, the continuous solution domain of the problem (which may include up to three space dimensions and time) is replaced by a grid function, and the solution to finite difference equations or finite element approximations is sought at this finite number of points.
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Subwatersheds and small plots within these watersheds often were instrumented in an attempt to understand the pathways ancl dynamics of water flow. Problems of scale ancl spatial variability of precipitation, soil, ancl vegetation became apparent very early ancl led to the establishment of much larger experimental watersheds by the Agricultural Research Service (ARS)
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From page 24... ...
In particular, the ADA watersheds were oriented toward understanding the transport, fate, and long-term patterns of the two primary atmospheric deposition chemical species, sulfur and nitrogen. The ADA watersheds have been successful intensive process research sites in terms of both scientific productivity and longevity.
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From page 25... ...
Accordingly, for the WEBB, ADA, or HEN watersheds to remain valuable enough to warrant continuation, the USGS must begin utilizing such sites as generic research resources and abandon their use as single-issue field sites. As new water-related problems emergecl, they were either aciciressecl at existing experimental watersheds or new watersheds were established to obtain the required data.
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From page 26... ...
As models were critically tested using data from experimental watersheds, the scientific community has again recognized the importance of watershed research. The National Research Council's Committee on Opportunities in the Hyclrologic
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From page 27... ...
These processes integrate traditional water resource management objectives, such as flood damage reduction, water supply, ancl navigation with environmental objectives such as water quality, soil erosion reduction, ground water recharge, and biodiversity conservation. MuItiple-objective processes require a much more complex analysis of watershed hydrology than the engineering designs of the past, which assumed essentially static quantities of water moving through the system (water quality was generally not addressed)
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From page 28... ...
The USGS should assess its programs and direct future efforts to help fill gaps in the knowlecige base in watershed science to ensure that pot icy decisions can be i nformecl by sol id scientific resu Its. I n Chapter 4 the committee presents its views of gaps in the scientific knowledge base that might be targets in strategic planning for future work by the USGS.
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From page 29... ...
Data Research Site and Agencies No. of Watershed size Collection Types of Involved Watersheds Range (ha)
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From page 30... ...
Geo/ogica/ Survey Data Research Site and Agencies No. of Watershed size Collection Types of Involved Watersheds Range (ha)
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From page 31... ...
of Wash. WISCONSIN North Temperate Lakes NSF, USGS 24 0.26-1 22.6 5 0.47-52,834 8 1.62 2 2.1-2.55 4 2.7-5.56 9 Up to 6,400 3 71 8-41,970 Up to 59 1-9 Up to 33 1,2,4,5,6,7,8 20 1,2,4,5,6,7,8,9 14 1,2,4,5,6,7,8,9 19 1,2,4,5,6,7,8,9,1 0 Up to 1 1 1,2,4,6,7,8,9,10 Up to 67 1,2,3,6 1 53 Up to 11 1,2,4,6,9 18 0.1 0-1 25 Up to 59 1 ,2,4,5,6,7,8,9 4 47-11,160 Up to 35 1-8 1 58 Up to 11 1,2,4,5,6,8,9 1 12,000 Up to 75 1-10
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From page 32... ...
Data Collection Types of History (yr) Dataa PUERTO RICO Luquillo Forest USDA-FS, NSF, USGS 4 0.33-2.64 up to 28 1-9 a key to types of data: 1, meteorological; 2, surface water quality; 3, ground water levels; 4, surface water chemistry; 5, ground water chemistry; 6, soil; 7, sediment; 8, land use; 9, vegetation; 10, animal.
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