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APPLICATION OF A MULTIPURPOSE UNEQUAL-PROBABILITY STREAM SURVEY IN THE MID-ATLANTIC COASTAL PLAIN
Citation:
Ator, S. W., A R. Olsen, A M. Pitchford, AND J. M. Denver. APPLICATION OF A MULTIPURPOSE UNEQUAL-PROBABILITY STREAM SURVEY IN THE MID-ATLANTIC COASTAL PLAIN. JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION 39(4):873-885, (2003).
Impact/Purpose:
The overarching objective is to develop and test landscape indicator statistical models for condition of streams and aquatic biota in relation to pesticides, nutrients, sediments and toxic substances, nationwide. The indicator models will serve as tools for managers who want consistent methods to compare potential impacts on streams within a biophysical region for differing landscape patterns. To accomplish this objective, several sub objectives will be important:
Develop landscape indicator statistical models of stream vulnerability for selected regions of the U.S., beginning with the Mid-Atlantic Coastal Streams; studies in the Midwest, California, and the Southeast will follow.
Demonstrate the application of the landscape indicator models for the ranking of watersheds, the identification of "hot spots," and the evaluation of management options using projected future scenarios of land use for the study areas selected above.
Develop statistical distributions for physical characteristics of small water bodies for use in OPP modeling.
Leverage resources for this research by incorporating existing data into the model development process, and by sharing field study costs with other projects in the same geographic areas.
This task represents a topic area within the Landscape Sciences research program which is described in A National Assessment of Landscape Change and Impacts to Aquatic Resources. A 10-Year Research Strategy for the Landscape Sciences Program, EPA/600/R-00/001. It also supports the Regional Vulnerability Assessment (ReVA) Program.
Besides being responsive to the Office of Pesticide Programs, this research directly supports long-term goals established in ORD's multi-year research plans related to GPRA Goal 2 (Water Quality) and GPRA Goal 8.1.1 (Sound Science/Ecological Research). Relative to the GPRA Goal 2 multi-year plan, this research will "provide tools to assess and diagnose impairment in aquatic systems and the sources of associated stressors" and "provide the tools to restore and protect aquatic ecosystems and to forecast the ecological, economic, and human health outcomes of alternative solutions" (Long Term Research Goals 2 and 3). Relative to the Goal 8 multi-year plan, this research will develop and demonstrate methods to provide states, tribes, and federal, state and local managers with abilities to: (1) assess the condition of waterbodies in a scientifically-defensible and representative way, while allowing for aggregation and assessment of trends at multiple scales; (2) diagnose cause and forecast future condition in a scientifically defensible fashion to more effectively protect and restore valued ecosystems; and (3) assess current and future ecological conditions, probable causes of impairments, and management alternatives.
Description:
A stratified random sample with unequal-probability selection was used to design a multipurpose survey of headwater streams in the Mid-Atlantic Coastal Plain. Objectives for data from the survey include unbiased estimates of regional stream conditions, and adequate coverage of unusual but important environmental settings to support empirical modeling of the factors affecting those conditions. A sample of 175 first-order non-tidal streams was randomly selected for synoptic sampling of water chemistry and benthic and riparian ecology during the late winter and spring of 2000. Twenty-five streams were chosen within each of seven hydrogeologic subregions (strata) that were delineated from physiography and surficial geology. In each subregion, unequal inclusion probabilities were used to provide an approximately even distribution of streams along a gradient of forested to developed (agricultural or urban) land in the contributing watershed. Alternate streams were also selected. Sampling sites on selected streams were located in the field on the basis of accessibility; alternates were included in groups of five in each subregion when field reconnaissance demonstrated that primary streams were inaccessible or otherwise unusable. Despite the rejection and replacement of a considerable number of primary streams during reconnaissance (up to 40 percent in one subregion), the desired land-use distribution was maintained within each hydrogeologic subregion without sacrificing the probabilistic design.