Does the model estimate mean annual loads for years other than the 1992 base year?
|Back to Top| The SPARROW model was used to simulate stream nitrogen and phosphorus load for 2002, based on changes in the model inputs of major nutrient sources from 1992-2002, to evaluate the robustness of the nutrient source shares, as reported in Table 2 of the article, to these decadal changes in sources. These model simulations assume that the model parameters, mean streamflow, and model errors are unchanged over time. Loads predicted for 2002 (versus those modeled for the 1992 base year) reflect updated information (or changes) in population and agricultural sources (animal manure, biological nitrogen fixation in crops, farm fertilizers use, and crop harvesting). Therefore, estimates in flux in 2002 only reflect changes in nutrient sources and are independent of the actual changes in streamflow from 1992 to 2002. In addition, the 2002 simulations do not include the effects of any changes in farm management practices unrelated to crop fertilizer use and production or animal popul
