A calibrated SPARROW model can be applied in a number of ways to provide information about nutrient loading. Because all information in the SPARROW model is spatially referenced, many of these applications can be shown in the form of maps. Such maps provide information about the spatial distribution of environmental factors that affect nutrient loading and provide spatial detail that is currently not available using most other watershed modeling tools. Spatially detailed illustrations of nutrient loads and the factors that affect them can be used as tools for targeting management practices or for other purposes. To illustrate ways in which a SPARROW model can be applied, selected examples of the total nitrogen model applications are shown in figures 8-12, and are described below