TCM-Manager: a PC-based total catchment management decision support system

Abstract

To date, little research effort has been directed towards developing a catchment-based resource management decision support system (DSS) that adequately integrates technical environmental information and sophisticated computer computational and graphical techniques. The environmental industry is currently without a rapid and cost-effective PC-based method by which to manage water catchments and assess the accumulated impacts of proposed development activities. A computer simulation system called TCM-Manager has been developed to assist the understanding of and management of complex land-use changes. The distributed model takes a catchment approach and applies the principles of total catchment management (TCM) to simulate the impacts of land-use change on environmental flows. Although extensive site-specific calibration is possible depending on existing environmental databases. TCM-Manager requires only initial study area topographic and land-use data to predict water, sediment and nutrient fluxes. Two time scales may be simulated. STORM simulations make use of coupled surface-subsurface distributed models to determine short-duration storm hydrographs and pollutographs. ANNUAL simulations estimate yearly water and contaminant flows. Both simulations require minimal information for immediate operation. Multiple, hierarchical and complex land-use changes may be simulated so that accumulated impacts of management decision scenarios can be assessed. The strength of TCM-Manager is that it provides an accessible, realistic and user-friendly graphical platform from which extensive preliminary catchment impact assessment, planning and management may be performed. It is intended to be used by resource managers and has been constructed to facilitate use without extensive calibration and user-expertise. Under this philosophy, the system is also suitable for secondary and tertiary education, environmental engineering and sensitivity analysis. The system provides several report formats that summarise simulations, determine water quality compliance, partly interpret results, and provide decision support based on simulation findings.