Grantee Research Project Results
2006 Progress Report: A Watershed Classification System for Improved Monitoring and Restoration: Landscape Indicators of Watershed Impairment
EPA Grant Number: R831369Title: A Watershed Classification System for Improved Monitoring and Restoration: Landscape Indicators of Watershed Impairment
Investigators: Prince, Stephen D. , Weller, Donald E. , Jordan, Thomas E. , Goetz, Scott J.
Institution: Mid-Atlantic Regional Earth Science Applications Center , Smithsonian Environmental Research Center , Woods Hole Research Center
Current Institution: University of Maryland - College Park , Smithsonian Environmental Research Center , Woods Hole Research Center
EPA Project Officer: Packard, Benjamin H
Project Period: February 1, 2004 through January 31, 2007
Project Period Covered by this Report: February 1, 2006 through January 31, 2007
Project Amount: $896,497
RFA: Development of Watershed Classification Systems for Diagnosis of Biological Impairment in Watersheds and Their Receiving Water Bodies (2003) RFA Text | Recipients Lists
Research Category: Watersheds , Water
Objective:
To develop a watershed classification scheme based on recent, much improved, comprehensive watershed data sets to diagnose aquatic ecosystem impairment and to target resource management. To use hydrologic metrics, nutrient budgets incorporating point and non-point source/sinks, and landscape function metrics to provide indicators of aquatic ecosystem condition (hydrology, plant, fish, macroinvertebrates, water quality) in reference watersheds. To identify the watershed variables most relevant to prediction of impairment of the receiving water bodies by developing a set of empirical classification models for multiple scales. To develop classifications for mid-Atlantic training watersheds, test them in the mid-Atlantic, apply the entire methodology in southern New England (MA, RI, CT), and to generalize the methods for future national application.
Progress Summary:
Nutrient Budgets
The net anthropogenic phosphorus input (NAPI) to counties of the Chesapeake Bay Watershed (CBW) has been revised by quantifying all phosphorus inputs and outputs for each county. NAPI values for 266 Chesapeake Bay counties ranged from -0.7 to 78.8 kg P/ha. The overall average of 4.75 kg P/ha indicates a positive net phosphorus input that can accumulate in the landscape or can pollute the water. Among nine major Chesapeake Bay tributary whole-watershed NAPI estimates explained 31% of the variability in measured P discharge. Developed land explained a higher (82%) proportion. For the nine watersheds, about 2% of the total NAPI reached the Chesapeake Bay, but highly urbanized areas in the Coastal Plain increase the proportion of NAPI discharged to the Bay to 9%. Human population density, livestock unit density, percent low density development, and percent row crop land explained 93% of the variability in NAPI.
In the more urbanized counties in MD, fertilizer applications to lawns and golf courses dominated net anthropogenic N and P inputs, but cropland fertilizer becomes more important above 9% cropland in a county. Annual urban fertilizer input in MD ranged up to 46.8 kg N/ha and 1.87 kg P/ha. Simple regression models successfully predict urban fertilizer application from land cover or human population data.
Water Quality Responses
The spatial patterns of land cover differed between the physiographic provinces. Riparian buffer patterns and stream map resolution affected inferences about whether retention occurs in streams or riparian zones. Increasing stream map resolution generally led to reduced estimates of nutrient retention potential in riparian buffers.
With all watersheds considered together, watershed characteristics explained 38% of county nutrient budgets phosphorus flux and 78% of nitrogen flux in streams, and the flux variability explained increased dramatically when watersheds were grouped by physiographic province.
Biological Responses
Mid-Atlantic Integrated Assessment (MAIA), Mid-Atlantic Highlands Assessment (MAHA), and Maryland Biological Stream Survey (MBSS) assessments differed in their estimates of stream health. While MBSS and MAHA were the most highly correlated, the magnitudes of percent Ephemeroptera, Plecoptera, and Trichoptera (EPT) taxa in the MBSS is about double the MAHA.
Response models were built using a full suite of watershed characteristics as the independent variables. This included land cover percentages from the Mid-Atlantic Regional Earth Science Applications Center (RESAC) land cover maps (total forest, total developed land, average tree canopy cover, average impervious cover, elevation, average annual precipitation, number of mines, number of dams, and number of point sources). The models accounted for 11–52% of the variability in % EPT taxa among MBSS MAHA samples. The impervious and tree-cover metrics were found to be the best predictors of stream health measured by biotic indices, and the strength of the relationships varied with physiographic province. Landscape configuration was important in many watersheds, but not all. These results indicate that stream health can usefully be estimated using land cover characteristics.
Regional Water Quality Modeling
In an associated project sponsored by the National Aeronautics and Space Administration (NASA), current Version 3.0 U.S. Geological Survey (USGS) Spatially Referenced Regressions on Watershed Attributes (SPARROW) total nitrogen (TN)/total phosphorus (TP) models have been reparameterized for the Chesapeake Bay Watershed. The results confirmed findings of the finer-scale analyses reported here, notably the importance of the riparian buffer, impervious surfaces, and agriculture. New landscape metrics-based TN and TP models utilizing 31 m riparian buffers associated with SPARROW’s enhanced river file network of the watershed explained 93.66% and 75.03% of the variation in natural logarithms of mean annual TN and TP flux, respectively. Both models improved upon results of model runs using the original land-cover metrics. Highest delivered TN yields (> 18 kg/ha/yr) were found in the lower Susquehanna River Valley of southeastern Pennsylvania and along northern and central catchment of the Delmarva Peninsula. Greatest TP yields (> 0.99 kg/ha/yr) were also concentrated in southeastern Pennsylvania, near Lancaster County.
Testing the Methods Developed for the Chesapeake Bay Watershed (CBW)) in Southern New England (NE)
The land-cover data that have proved useful in CBW are to be applied to NE. Subpixel impervious surface cover areas (% ISA) and a sub-pixel forest canopy map, separated into deciduous and evergreen cover, have been prepared from Landsat visible-near infrared and Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) short wave infrared satellite data.
Future Activities:
The principal tasks remaining are:
- Synthesis of the landscape metrics that have been shown to provide significant indications of water quality, as judged by N, P, and biotic indices.
- Calculate metrics for all the measured watersheds to quantify the accuracy and precision of the estimation of impairment.
- Application to the entire Chesapeake Bay watershed
- Test in New England watersheds with runoff and biotic water quality indices.
- Assessment of the methodology by Watershed Managers.
Journal Articles on this Report : 2 Displayed | Download in RIS Format
| Other project views: | All 70 publications | 19 publications in selected types | All 15 journal articles |
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Baker ME, Weller DE, Jordan TE. Effects of stream map resolution on measures of riparian buffer distribution and nutrient retention potential. Landscape Ecology 2007;22(7):973-992. |
R831369 (2006) R831369 (Final) R828684 (Final) |
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Goetz SJ. Remote sensing of riparian buffers: past progress and future prospects. Journal of the American Water Resources Association 2006;42(1):133-143. |
R831369 (2006) R831369 (Final) R828684 (Final) |
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Supplemental Keywords:
USGS, MRLC, NLCD, integrated assessment, remote sensing, geospatial technology, Chesapeake Bay, New England,, RFA, Ecosystem Protection/Environmental Exposure & Risk, Scientific Discipline, Water, Ecological Risk Assessment, Watersheds, Monitoring/Modeling, Hydrology, Water & Watershed, Ecology and Ecosystems, Environmental Monitoring, water quality, aquatic ecosystem, water monitoring, environmental stress, land use, hydrologic modeling, watershed classification, aquatic ecosystems, continuous monitoring, ecosystem restoration, land managementRelevant Websites:
http://www.geog.umd.edu/resac/ Exit
http://www.whrc.org/midatlantic/index.htm Exit
http://www.serc.si.edu/labs/ecological_modeling/landuse_discharge.jsp Exit
Progress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.