The Use of Simulation Models as Resource Management Tools for Restoring Acidified Waters

Abstract

Several computer simulation models are available to resource managers for predicting the response of watersheds and adjacent surface waters to acidification and subsequent neutralization. Some of these models are useful in designing and implementing liming restoration programs. The simpler models emphasize in-lake biochemical processes involved in the dissolution of CaCO₃ and dilution hydrology; these are best suited for simulating straightforward direct applications to surface waters that have minimal hydrologic interaction with the terrestrial watershed. The more sophisticated models integrate various complex biogeochemical processes in land catchments in addition to in-lake and in-stream chemistry. These are best suited for rigorous, process-oriented research applications, for systems which have significant hydrologic interaction with the terrestrial catchment, and for simulating catchment liming applications. The approach and results from a recently published liming simulation study employing the modified Integrated Lake-Watershed Acidification (ILWAS) model are used to illustrate the methodology for using simulation models to complement field research and operational liming programs. Also, modifications to existing models are identified for increasing their suitability for more robust management applications under a wider variety of conditions in different regions.