Uncertainty in Regional-Scale Assessments of Non-Point Source Pollutants

Assessments of non-point source pollution, with mathematical models designed to produce multicolored maps, are now being used in the decision management arena. This has been possible primarily because of the marriage of solute transport models to geographic information systems that add a geo-referenced dimension to transport models. Albert Einstein said that “everything must be made as simple as possible, but not simpler.” The utility of relatively simple vulnerability maps, which have been produced at regional scales with geographic information system technology, is undermined by significant uncertainties related to model and data errors. In this chapter, the three most commonly used methods for characterizing simulation uncertainties are discussed: sensitivity analysis, first-order analysis, and Monte Carlo analysis. Examples of each method are presented. Contamination of both surface water and groundwater resources is a global environmental concern. Non-point sources (NPS) of contamination, with all the implications of scale and variability (both spatial and temporal), pose, potentially, even greater environmental problems than those from point sources due to long-term stresses imposed across thousands of hectare s (Loague et al., 1996). The increasing availability of geographic information system (GIS) software to those involved in the technical support of land use decisions has resulted in the generation of multicolored management maps for regional targeting and risk

[1]  Richard E. Green,et al.  Uncertainty in a pesticide leaching assessment for Hawaii , 1989 .

[2]  John L. Casti,et al.  Searching for Certainty: What Scientists Can Know about the Future , 1992 .

[3]  D. Bosch.  Ground Water Vulnerability Assessment: Predicting Relative Contamination Potential under Conditions of Uncertainty , 1995 .

[4]  P. Burrough.  Principles of Geographical Information Systems for Land Resources Assessment , 1986 .

[5]  Keith Loague.  Impact of rainfall and soil hydraulic property information on runoff predictions at the hillslope scale , 1988 .

[6]  J. D. Hanson,et al.  Sensitivity analysis of a general rangeland model , 1985 .

[7]  Steven M. Gorelick,et al.  Groundwater Contamination Optimal Capture and Containment , 1993 .

[8]  Howard Raiffa,et al.  Decision analysis: introductory lectures on choices under uncertainty. 1968. , 1969, M.D.Computing.

[9]  R. Raucher,et al.  Groundwater contamination risk assessment: a guide to understanding and managing uncertainties. , 1990 .

[10]  Anand Patwardhan,et al.  Bayesian Methods for Model Uncertainty Analysis with Application to Future Sea Level Rise , 1992 .

[11]  Joel Massmann,et al.  Hydrogeological Decision Analysis: 4. The Concept of Data Worth and Its Use in the Development of Site Investigation Strategies , 1992 .

[12]  J. Kremer,et al.  Frequency-domain sensitivity analyses of an estuarine ecosystem simulation model , 1983 .

[13]  R. Zhang,et al.  Applied Contaminant Transport Modeling: Theory and Practice , 1991 .

[14]  D. Lettenmaier,et al.  PROBABILISTIC METHODS IN STREAM QUALITY MANAGEMENT , 1975 .

[15]  Reuven Y. Rubinstein,et al.  Simulation and the Monte Carlo Method , 1981 .

[16]  M. B. Beck,et al.  Water quality modeling: A review of the analysis of uncertainty , 1987 .

[17]  Richard E. Green,et al.  Simulation of Organic Chemical Movement in Hawaii Soils with PRZM: 1. Preliminary Results for Ethylene Dibromide , 1989 .

[18]  Richard E. Green,et al.  Impact of uncertainty in soil, climatic, and chemical information in a pesticide leaching assessment , 1990 .

[19]  K. Loague.  Simulation of Organic Chemical Movement in Hawaii Soils with PRZM: 3. Calibration , 1992 .

[20]  Keith Loague,et al.  The impact of land use on estimates of pesticide leaching potential: Assessments and uncertainties , 1991 .

[21]  N Oreskes,et al.  Verification, Validation, and Confirmation of Numerical Models in the Earth Sciences , 1994, Science.

[22]  Max Henrion,et al.  Uncertainty: A Guide to Dealing with Uncertainty in Quantitative Risk and Policy Analysis , 1990 .

[23]  Stephen F. Moore,et al.  Estimation Theory Applications to Design of Water Quality Monitoring Systems , 1973 .

[24]  Vijay P. Singh,et al.  Application of uncertainty analysis to groundwater pollution modeling , 1995 .

[25]  Clark C.K. Liu,et al.  Simulation of Organic Chemical Movement in Hawaii Soils with PRZM: 2. Predicting Deep Penetration of DBCP, EDB, and TCP , 1989 .

[26]  John L. Casti,et al.  Searching for Certainty , 1990 .

[27]  R. Allan Freeze,et al.  Role of subsurface flow in generating surface runoff: 1. Base flow contributions to channel flow , 1972 .

[28]  John D. Bredehoeft,et al.  Ground-water models cannot be validated , 1992 .

[29]  Joel Massmann,et al.  Hydrogeological Decision Analysis: 1. A Framework , 1990 .

[30]  J. Kou,et al.  A method for quantifying the prediction uncertainties associated with water quality models , 1993 .

[31]  Joel Massmann,et al.  Hydrogeological Decision Analysis: 2. Applications to Ground‐Water Contamination , 1991 .

[32]  K. Loague,et al.  Statistical and graphical methods for evaluating solute transport models: Overview and application , 1991 .

[33]  H Raiffa,et al.  Decision Analysis: Introductory Lectures on Choices under Uncertainty. , 1969 .

[34]  Mitchell J. Small,et al.  Risk‐based environmental remediation: Decision framework and role of uncertainty , 1994 .

[35]  J. Hammersley.  SIMULATION AND THE MONTE CARLO METHOD , 1982 .

[36]  R. Allan Freeze,et al.  A Comparison of Rainfall-Runoff Modeling Techniques on Small Upland Catchments , 1985 .

[37]  A C Taylor,et al.  The value of animal test information in environmental control decisions. , 1993, Risk analysis : an official publication of the Society for Risk Analysis.

[38]  J S Evans,et al.  Evaluating the benefits of uncertainty reduction in environmental health risk management. , 1987, JAPCA.

[39]  Keith Loague.  Regional Scale Ground‐Water Vulnerability Estimates: Impact of Reducing Data Uncertainties for Assessments in Hawaii , 1994 .

[40]  Richard Bernknopf,et al.  Uncertainty of Groundwater Vulnerability Assessments for Agricultural Regions in Hawaii: Review , 1996 .

[41]  J. Evans,et al.  Assessing the value of hydrogeologic information for risk‐based remedial action decisions , 1989 .

[42]  Gareth Edwards-Jones,et al.  Ground water vulnerability assessment. Predicting relative contamination potential under conditions of uncertainty: National Research Council. National Academy Press, 1993. 204 pp. Price US$ 34.95, US$ 42.00 export (hardback). ISBN 0 309 04799 4 , 1996 .

[43]  Dennis L. Corwin,et al.  GIS Applications of Deterministic Solute Transport Models for Regional-Scale Assessment of Non-Point Source Pollutants in the Vadose Zone , 1996 .

[44]  R. Allan Freeze,et al.  A stochastic‐conceptual analysis of rainfall‐runoff processes on a hillslope , 1980 .

[45]  C. T. Haan,et al.  An approach to estimating uncertainties in modeling transport of solutes through soils , 1993 .

[46]  Joel Massmann,et al.  Hydrogeological Decision Analysis: 3. Application to Design of a Ground‐Water Control System at an Open Pit Mine , 1992 .

[47]  Richard E. Green,et al.  Chemical Leaching Near the Waiawa Shaft, Oahu, Hawaii: 2. Modeling Results , 1995 .