Impact/Purpose:

This project has three overall goals: 1) To develop efficacious methods for quantitative assessment of riparian resources at a both local and watershed scales; 2) to examine land use elements, at various scales as regulators of both water quality and biological integrity in freshwater streams, and 3) to elucidate the potential of riparian corridors to ameliorate various stressor impacts from the surrounding catchment.

Approach

-FY00 Activities The field sampling conducted in the first year will be repeated for all of the sub-watershed sites in the second year. Using the sub-watershed boundaries determined via the hydrologic models the landscape metrics for each sub-watershed will be developed. Likewise the high resolution land cover data for the riparian corridors will be developed from the digitized aerial photography.

-FY01 Activities The field sampling conducted in the years one and two will be repeated for all of the sub-watershed sites in year three. The field data from all three years will be combined to develop the indices of water quality and biotic integrity for the sub-watersheds. The stream quality and land cover data from the watershed catchment area and the riparian corridor will be correlated using a series of step-wise, multistage, linear regression models. Individual features of stream quality will be related to various riparian land cover parameters and other land use elements in the watershed as a whole. Statistical analysis will be completed.

-FY02 Activities Final reports and manuscripts for submission to the peer reviewed scientific literature will be prepared.

Description:

Landscape features (e.g., land use) influence water quality characteristics on a variety of spatial scales. For example, while land use is controlled by anthropogenic features at a local scale, geologic features are set at larger spatial, and longer temporal scales. Individual water quality features may be independently influenced by different landscape features and different scales. For example, recent studies in the North Central U.S. indicate that while nutrient loadings are influenced predominantly by local riparian vegetation, some measures of biological integrity may be more profoundly influenced by landscape elements on a larger spatial scale (e.g., soil type, slope and elevation). In order to develop the most beneficial land use options and to direct remedial efforts to address watershed land use policies for maintaining and improving water quality, it is necessary to understand both the role of riparian corridors (specifically) as well as the differential influence of scale in land use (generally) on watershed integrity and water quality.

Record Details:

Record Type:PROJECT

Start Date:12/01/2000

Completion Date:10/15/2001

Record ID: 59015

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Project Information:

Progress :A large number of digital data sets (e.g., Land cover, HUC's, political lakes and static water bodies; stream reach files. physiography, hydrogeomorphology, soil regions, bedrock and sedimentary coverages, ecoregions, glacial geology; sites of dischargers and water intakes, and pervious published biological/chemical sampling sites, elevation data, population demographics, and agricultural data) have been assembled and transformed into a common geographic projection. A set of 35 sub-watersheds (18 - 35 km2 ) have been selected using the USGS 14-digit HUC's as the starting point. These sub-watersheds have been arrayed by area/perimeter and the stream reaches were clipped from the RF3 file and subsequently, analyzed for land cover via the ArcView Spatial Analyst extension and those sub-watersheds with greater than 2% urban land cover were rejected. A work assignment has been prepared and approved to conduct an detailed assessment of the actual total drained area in each of the sub-watersheds using a GIS-based hydrologic model. Using county tax records, the names and addresses of landowners around each selected study site were identified and each was notified by mail of the USEPA's desire to access their property for the study purposes. Written access permission was obtained from property owners for each sub-watershed sites and detailed site maps and information (ArcView GIS) and access route maps were prepared.

A work assignment was prepared and approved for a field sampling crew to visit each sub-watershed in July/August, 1999 to conduct stream assessments using USEPA surface water methods (e.g.,water chemistry, physical habitat, stream bed/bank measurements, riparian assessments, periphyton, benthic invertebrates and fish assembledges). All field work for the 1999 season has been completed and water chemistry and fish assembledge data collected on these visits have been processed. A work assignment had been prepared and approved to permit the scanning, digitization, rectification, and classification of the aerial photographic imagery. This data will be supplied in ArcView GIS format for the hi-resolution land cover classification of the riparian corridor using the Spatial Analyst extension. A work assignment has been prepared to permit the calculation of landscape metrics over the drained area in each study sub-watersheds. This project will use the MLRC data base in conjunction with an application of the US EPA NERL-LV Attila Landscape Metrics Program. Finally, a comprehensive quality assurance document for the project including project planning/management, data quality objectives, measurement and data acquisition, and data base management as been prepared and submitted to the NERL Quality Assurance Office.

A work assignment was prepared and approved for a field sampling crew to visit each sub-watershed in July/August, 2000 to conduct stream assessments using USEPA surface water methods (e.g.,water chemistry, physical habitat, stream bed/bank measurements, riparian assessments, periphyton, benthic invertebrates and fish assembledges). All field work for the 2000 season has been completed.

The drainage area for all of the LMR study watersheds have been defined by NERL-LV using an ArcInfo-based hydrological model in conjunction with the National Elevation data set and the reach file for each stream were digitized using geo-rectified aerial photography from September 1998. These reach files have been used to generate a riparian buffer file and the land cover in the riparian zones will be determined by overlaying the riparian buffers on the aerial photographs.

Two erosion models, both based on land cover, slope, and soil grids have been developed and are being used to evaluate the relationship of catchment and riparian land cover and geology to stream embeddedness.

Relevance :Landscape features (e.g., land use), influence water quality characteristics on a variety of spatial scales. For example, riparian zones, the vegetated areas along stream corridors serve as the interface between the water body and the surrounding terrestrial ecosystem and operate on a proximal spatial scale to enhance stream integrity/water quality by providing both services (e.g., allochthonous energy) and protection (e.g., reducing nutrient loadings). In contrast, other elements set at larger spatial (and longer temporal) scales, e.g., overall land cover/land use in a basin, or geologic features (e.g., topography, soils etc.), also influence watershed integrity. Thus, individual water quality features appear frequently to be independently influenced by multiple landscape features operating at different scales. An important consequence of this situation is therefore, that scale is also a factor in selecting the most appropriate option for watershed restoration (e.g., restoring riparian vegetation vs. instituting a no-till farm program in the basin). Critically important tools for rationalizing this issue of scale, for both the instigation and the mitigation, of watershed stressors are lacking.

Clients :Office of Water programs dealing with watershed protection; OW's XL project group (Lisa Riter); Region 5 (Wayne Gorski & Chris Murphy)

Project IDs:

ID Code :5571

Project type :OMIS