1Department of Environmental Sciences, University of Virginia, Charlottesville, VA22901 USA
2Macaulay Institute, Craigiebuckler, Aberdeen AB9 2QJ, UK
3Centre for Ecology and Hydrology, Wallingford, Oxon OX10 8BB, UK
4Norwegian Institute for Water Research, Box 173 Kjelsas, N-0411 Oslo, Norway
Email for corresponding author: B.J.Cosby@virginia.edu
Abstract. The MAGIC model of the responses of catchments to acidic deposition has been applied and tested extensively over a 15 year period at many sites and in many regions around the world. Overall, the model has proven to be robust, reliable and useful in a variety of scientific and managerial activities. Over the years, several refinements and additions to MAGIC have been proposed and/or implemented for particular applications. These adjustments to the model structure have all been included in a new version of the model (MAGIC7). The log aluminium – pH relationship now does not have to be fixed to aluminium trihydroxide solubility. Buffering by organic acids using a triprotic analog is now included. Dynamics of nitrogen retention and loss in catchments can now be linked to soil nitrogen and carbon pools. Simulation of short-term episodic response by mixing fractions of different water types is also possible. This paper presents a review of the conceptual structure of MAGIC7 relating to long-term simulation of acidification and recovery, describes the conceptual basis of the new nitrogen dynamics and provides a comprehensive update of the equations, variables, parameters and inputs for the model.
Keywords: process-based model, acid deposition, recovery
Cosby, B. J., Ferrier, R. C., Jenkins, A., and Wright, R. F.: Modelling the effects of acid deposition: refinements, adjustments and inclusion of nitrogen dynamics in the MAGIC model, Hydrol. Earth Syst. Sci., 5, 499-518, doi:10.5194/hess-5-499-2001, 2001.