What metrics do SPARROW models predict?
|Back to Top| SPARROW models are developed using mass balance constraints to quantify the relation between stream constituent load (the mass of the constituent being transported by the stream) and the sources and losses of mass in watersheds. Thus the models are inherently designed to predict load (mass per time) for all stream reaches in the modeling region. However, the predictions of stream load can be modified to provide a variety of water-quality metrics that can support various types of assessments. The SPARROW prediction metrics include constituent yields, concentrations, and source contributions to stream loads: (a) Constituent yields: |Back to prediction metrics| The constituent yield (mass per unit area per time) is calculated as the stream load divided by the contributing drainage area. Measures of yield are useful for water-quality managers to determine the relative contribution of contaminants from different parts of a large drainage area. Contaminant loading typically inc
