How are watershed characteristics used in SPARROW models?
|Back to Top| In the same way that SPARROW identifies the relative importance of contaminant sources to streams, it also estimates the importance of landscape factors in the delivery of those contaminants to streams. SPARROW imposes mass balance constraints on all estimates of contaminant loading. Thus all sources must be balanced by environmental attenuation processes (losses) in order to estimate the measurements of stream loading with minimal error. For example, nutrients originating from agricultural land may be lost through denitrification as they are transported from the land surface through shallow ground water to streams. Soil permeability may enhance denitrification and so the spatial distribution of the value of soil permeability may be related to contaminant loading downstream. Any landscape characteristic could be evaluated as a potential loss factor for delivery of contaminants to streams. Landscape characteristics can only be statistically identified as important if they
