Quantifying Uncertainty in Critical Loads: (B) Acidity Mass Balance Critical Loads on a Sensitive Site
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This paper reports an uncertainty analysis of critical loads for acid deposition for a site in southern England, using the Steady State Mass Balance Model. The uncertainty bounds, distribution type and correlation structure for each of the 18 input parameters was considered explicitly, and overall uncertainty estimated by Monte Carlo methods. Estimates of deposition uncertainty were made from measured data and an atmospheric dispersion model, and hence the uncertainty in exceedance could also be calculated. The uncertainties of the calculated critical loads were generally much lower than those of the input parameters due to a “compensation of errors” mechanism – coefficients of variation ranged from 13% for CLmaxN to 37% for CL(A). With 1990 deposition, the probability that the critical load was exceeded was > 0.99; to reduce this probability to 0.50, a 63% reduction in deposition is required; to 0.05, an 82% reduction. With 1997 deposition, which was lower than that in 1990, exceedance probabilities declined and uncertainties in exceedance narrowed as deposition uncertainty had less effect. The parameters contributing most to the uncertainty in critical loads were weathering rates, base cation uptake rates, and choice of critical chemical value, indicating possible research priorities. However, the different critical load parameters were to some extent sensitive to different input parameters. The application of such probabilistic results to environmental regulation is discussed.
Keywordsacid deposition dispersion model critical load exceedance emission control environmental policy Liphook Monte Carlo analysis sensitivity analysis steady state mass balance model uncertainty analysis
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- Abbott, J., Hayman, G., Vincent, K., Metcalfe, S., Dore, T., Skeffington, R. A., Whitehead, P. G., Whyatt, D., Passant, N. and Woodfield, M.: 2003, ‘Uncertainty in acid deposition modelling and critical load assessments’, R&D Technical Report TR4-083(5)/1, Environment Agency (England and Wales), Bristol, UK.Google Scholar
- Barkman, A. and Alveteg, M.: 2001a, ‘Identifying potentials for reducing uncertainty in critical load calculations using the PROFILE model’, Water, Air Soil Pollut. 125, 33–54.Google Scholar
- Barkman, A. and Alveteg, M.: 2001b, ‘Effects of data uncertainty in the Swedish critical load assessment for forest soils’, Water, Air Soil Pollut. 125, 133–156.Google Scholar
- Cronan, C. S. and Grigal, D. F.: 1995, ‘Use of calcium/aluminum ratios as indicators of stress in forest ecosystems’, J. Env. Qual. 24, 209–226.Google Scholar
- Draaijers, G. P. J., Vanleeuwen, E. P., Dejong, P. G. H. and Erisman, J. W.: 1997, ‘Base cation deposition in Europe.1. Model description, results and uncertainties’, Atmos. Env. 31, 4139–4157.Google Scholar
- Hall, J. R., Ullyett, J., Hornung, M., Kennedy, F., Reynolds, B., Curtis, C., Langan, S. and Fowler, D.: 2001, ‘Status of UK critical loads and exceedances Part I. Critical Loads and Critical Load Maps, update to January 1998 report’, CEH, Monks Wood, Cambs, UK.Google Scholar
- Hall, J., Ullyett, J., Heywood, L., Broughton, R., Fawehinmi, J. and 31 UK experts: 2003, ‘Status of UK critical loads: Critical loads methods, data and maps, February 2003’, CEH, Monks Wood, Cambs, UK.Google Scholar
- Hall, J. R., Ullyett, J., Heywood, E. and Broughton, R.: 2004, ‘Status of UK critical loads, critical loads methods and maps, February 2004’, CEH, Monks Wood, Cambs, UK.Google Scholar
- Hettelingh, J.-P., Slootweg, J. and Posch, M.: 2004, ‘Critical loads and dynamic modelling results, CCE Progress Report 2004’, Report 259101014/2004, RIVM, Bilthoven, The Netherlands.Google Scholar
- Lee, D. S., Kingdon, R. D., Jenkin, M. E. and Garland, J. A.: 2000, ‘Modelling the atmospheric oxidised and reduced nitrogen budgets for the UK with a Lagrangian multi-layer long-range deposition model’, Env. Modelling Assessment 5, 83–104.Google Scholar
- Mcleod, A. R.: 1995, ‘An open-air system for exposure of young forest trees to sulphur dioxide and ozone’, Plant Cell Environ. 18, 215–225.Google Scholar
- Mcleod, A. R. and Skeffington, R. A.: 1995, ‘The Liphook forest fumigation project: An overview’, Plant Cell Environ. 18, 327–335.Google Scholar
- Morgan, M. G. and Henrion, M.: 1990, Uncertainty. A Guide to Dealing with Uncertainty in Quantitative Risk and Policy Analysis, Cambridge University Press, Cambridge.Google Scholar
- NAEI: 2002, UK National Atmospheric Emissions Inventory, http://www.naei.org.uk/.
- NEGTAP: 2001, Transboundary Air Pollution: Acidification, Eutrophication and Ground-Level Ozone in the UK, CEH, Edinburgh, UK.Google Scholar
- Posch, M.: 1999, ‘Defining an exceedance function’, in: M. Posch, P. A. M. de Smet, J.-P. Hettelingh and R. J. Downing (eds.), Calculation and Mapping of Critical Thresholds in Europe, Report 259101009, RIVM, Bilthoven, The Netherlands, pp. 29–32.Google Scholar
- Posch, M., de Smet, P. A. M., Hettelingh, J.-P. and Downing, R. J.: 1999, ‘Calculation and mapping of critical thresholds in Europe’, Report 259101009, RIVM, Bilthoven, The Netherlands.Google Scholar
- Posch, M., de Smet, P. A. M., Hettelingh, J.-P. and Downing, R. J.: 2001, ‘Modelling and mapping of critical thresholds in Europe: Status Report 2001’, Report 259101010, RIVM, Bilthoven, The Netherlands.Google Scholar
- Posch, M., Hettelingh, J.-P., Slootweg, J. and Downing, R. J.: 2003, ‘Modelling and mapping of critical thresholds in Europe: Status Report 2003’, Report 259101013/2003, RIVM, Bilthoven, The Netherlands.Google Scholar
- Reynolds, B.: 2000, ‘An evaluation of critical loads of soil acidity in areas of high sea salt deposition’, Sci. Tot. Env. 253, 169–176.Google Scholar
- Saltelli, A., Chan, K. and Scott, M. (eds.): 2000, Sensitivity Analysis, John Wiley, New York.Google Scholar
- Shaw, P. J. A. and Mcleod, A. R.: 1995, ‘The effects of SO2 and O3 on the foliar nutrition of Scots pine, Norway spruce and Sitka spruce in the Liphook Open-air Fumigation Experiment’, Plant Cell Environ. 18, 237–245.Google Scholar
- Skeffington, R. A.: 1999, ‘The use of critical loads in environmental policymaking: a critical appraisal’, Environ. Sc. Technol. 33, 245A–252A.Google Scholar
- Skeffington, R. A. and Sutherland, P. M.: 1995, ‘The effects of SO2 and O3 fumigation on acid deposition and foliar leaching in the Liphook forest fumigation experiment’, Plant, Cell Environ. 18, 247–261.Google Scholar
- Skeffington, R. A.: 2005, ‘Quantifying uncertainty in critical loads: (A) Literature review’, Water, Air Soil Pollut., this issue.Google Scholar
- Suutari, R., Amann, M., Cofala, J., Klimont, Z., Posch, M. and Schöpp, W.: 2001, ‘From economic activities to ecosystem protection in Europe. An uncertainty analysis of the RAINS integrated assessment model’, CIAM/CCE Report 1/2001, IIASA, Laxenburg, Austria.Google Scholar
- UNECE: 2004, ‘Manual on Methodologies and Criteria for Modelling and Mapping Critical Loads and Levels, and Air Pollution Effects, Risks and Trends’, http://www.icpmapping.org/html/manual.html.