Water, Air, and Soil Pollution

, Volume 105, Issue 3, pp 617–642

Reduced-Form Modelling of Surface Water and Soil Chemistry for the Tracking and Analysis Framework


    • Department of Civil and Environmental EngineeringCarnegie Mellon University
  • M. J. Small
    • Departments of Civil and Environmental Engineering and Engineering and Public PolicyCarnegie Mellon University
  • P. F. Ryan
    • Science Applications International Corporation
  • T. J. Sullivan
    • E&S Environmental Chemistry, Inc.
  • B. J. Cosby
    • Department of Environmental SciencesUniversity of Virginia

DOI: 10.1023/A:1004993425759

Cite this article as:
Sinha, R., Small, M.J., Ryan, P.F. et al. Water, Air, & Soil Pollution (1998) 105: 617. doi:10.1023/A:1004993425759


A reduced-from modelling approach is used to predict soil and lake acidification as part of an integrated assessment of acid deposition effects and control strategies. The reduced-form model is based upon the mechanistic, lumped parameter watershed chemistry model, MAGIC (Model of Acidification of Groundwater in Catchments). Recent improvements to MAGIC are described, and its reduced-form representation in the Tracking and Analysis Framework (TAF), an integrated assessment model for decision and uncertainty analysis, is presented. Reduced-form models are developed for lake acid neutralising capacity (ANC), calcium, pH, and aluminium; and for soil base saturation. The model for lake ANC incorporates long-term depletion of the watershed acid neutralisation fraction, as is predicted to occur with MAGIC. In test calibrations for 33 representative watersheds in the Adirondacks, the resulting reduced-form model provides a close approximation to MAGIC, with average root mean square errors of 0.79 μeq l-1 for ANC, 1.09 μeq l-1 for calcium, 0.16 for pH, 2.52 μeq l-1 for aluminium, and 0.09% for soil base saturation. In addition, improved fish viability models are incorporated in the integrated assessment model, and predictions are demonstrated for a future deposition reduction scenario for the Adirondack region.

acid depositionAdirondacksintegrated assessmentlake acidificationmathematical modelreduced-form modellingsoil acidification

Copyright information

© Kluwer Academic Publishers 1998