Nutrient management at the catchment scale using a decision support system

Abstract

To effectively manage the nutrient status of waterbodies, an ability to predict the likely external nutrient loadings from both point and diffuse sources under present and future conditions is important. The processes of nutrient export and transport are very complex, and detailed data and knowledge of these processes are seldom available without lengthy and expensive investigations. As an alternative, estimates of average annual catchment nutrient loads can provide an initial basis for strategic decision making, and indicate where more detailed investigations would be most beneficial. The Catchment Management Support System (CMSS) is a PC-based programme that was developed to calculate average annual nutrient loads and to allow the effects of land-use changes and land management changes to be investigated with ease. In addition, the CMSS approach stresses the importance of wide community involvement in the decision-making process for catchment management. The CMSS package is described, including the nutrient load prediction model used and its data requirements and the features of the user interface. A discussion of the role of CMSS in the decision-making process is made with reference to the imminent development of Nutrient Management Plans for many Australian catchments.