An ecological risk assessment paradigm using the Spatially Integrated model for Phosphorus Loading and Erosion (SIMPLE)
Tóm tắt
Ecological risk assessments provide a probabilitistic approach to analyzing and predicting ecosystem responses to stress. We are evaluating the relationship between nonpoint source (NPS) phosphorus loading and the trophic status of the aquatic ecosystem. We are using SIMPLE (the Spatially Integrated Model for Phosphorus Loading and Erosion) to identify probable phosphorus sources in a watershed, simulate the phosphorus loading to streams, and analyze the relationships between input variables and their ecological impact. The objective of this paper is to describe a risk-based paradigm using SIMPLE to characterize the probability of exceeding a critical phosphorus loading to a lotic ecosystem. We have characterized the risk of exceeding a threshold loading of 0.5 kilogram total phosphorus per hectare per year from a 2238 hectare watershed. Two-hundred-fifty random SIMPLE simulations were performed to estimate annual total phosphorus, dissolved phosphorus, and sediment-bound phosphorus loading to a lotic ecosystem from the watershed. Simulation results were analyzed statistically to determine the probabilities of exceeding the critical loadings. Based on the current land use practices in the Battle Creek watershed, the probability of exceeding the total phosphorus critical loading rate of 0.5 kg/ha/yr was approximately 11 percent, or one year in nine the total annual loading will exceed the critical loading rate. The 95 percent confidence intervals for the total phosphorus loading occurring on average once in nine years were relatively close (0.45 to 0.60 kg/ha/yr), assuming the only variability from year to year was due to natural variability in weather.
Tài liệu tham khảo
Cairns, J.Jr. & P. V.McCormick, 1991. The use of community- and ecosystem-level end points in environmental hazard assessment: a scientific and regulatory evaluation. Environ. Audit. 2: 239–248.
Cairns, J.Jr. & B. R.Niederlehner, 1993. Ecological function and resilience: neglected criteria for environmental impact assessment and ecological risk analysis. The Environ. Professional 15: 116–124.
Cairns, J.Jr., B. R.Niederlehner & D. R.Orvos, 1992. Predicting Ecosystem Risk. Princeton Scientific Publishing Co., Inc. Princeton, N.J., 347 pp.
Cairns, J. Jr. & J. R. Pratt, 1990. Integrating aquatic ecosystem resource management. Innovations in River Basin Management. In: R. McNeil & J. E. Windsor (eds), Canadian Water Resources Association. pp. 265–280. Cambridge, Ontario.
Chen, Z., D. E.Storm, M. E.Smolen, C. T.Haan, M. S.Gregory & G. J.Sabbagh, 1994. Prioritizing non-point source phosphorus loading using a GRASS-modeling system. Wat. Res. Bul. 30: 589–594.
Gakstater, J. H. & A.Katko, 1986. An Intensive Survey of the Illinois River (Arkansas and Oklahoma) in August 1985. Environmental Research Laboratory, Duluth, MN EPA/600/3–87/040.
Haan, C. T., 1977. Statistical Methods in Hydrology. The Iowa State University Press. Ames, Iowa. 0–8138–1510-X, 378 pp.
Haan, C. T., B. J.Barfield & J. C.Hayes, 1994. Design Hydrology and Sedimentology for Small Catchments. Academic Press. New York. 0–12–312340–2, 588 pp.
Jarman, R., 1984. The development of aquatic ecoregions in Oklahoma. Doctoral Dissertation, University of Oklahoma. Norman, OK. Minns, C. K., 1992. Use of models for integrated assessment of ecosystem health. J. Aquat. Ecosyst. Health 1: 109–118.
Richardson, C. W. & D. A. Wright (1984). WGEN, A model for generating daily weather variables. U.S. Department of Agriculture, Agriculture Research Service, ARS-8.
Soil Conservation Service (SCS), 1992. Illinois River Cooperative Basin Resource Base Report, 1991. U.S. Department of Agriculture Soil Conservation Service and Forest Service. Stillwater, OK.
Storm, D. E., G. J.Sabbagh, M. D.Smolen & C. T.Haan, 1993. A phosphorus model for NPS pollution prioritization. ASAE Paper No. 93–932074, ASAE. St. Joseph, MI.
Suter, G. W., 1993. Ecological Risk Assessment. Lewis Publishers. Ann Arbor, 538 pp.
US Army Corps of Engineers, 1991. Geographic Resources Analysis Support System Users Reference Manual. Construction Engineering Research Laboratory. Champaign, IL.
US Environmental Protection Agency, 1993. Profiles in risk assessment. In: EPA Journal, Vol 19, No. 1. EPA 175-N-93-014.
Vollenweider, R. A. & J. J. Kerekes, 1980. Background and summary results of the OECD cooperative program on eutrophication. Restoration of lakes and inland waters, US Environmental Protection Agency, EPA 220-5-81-010.
Wischmeier, W. H. & D. D.Smith, 1978. Predicting rainfall losses — a guide to conservation planning. Agricultural Handbook No. 537, U.S. Department of Agriculture. Washington, D.C.