Specific Catchment Area as a Basis of Design for Precision Riparian Buffers
Mathis, James E.
MetadataShow full item record
One of the most important functions of a riparian buffer is to act as a filter strip that removes sediment, nutrients and pollutants from stormwater runoff. Therefore, as a water treatment process, it is only logical that hydraulic loading should be an important factor in the effectiveness of the process. Using terrain analysis techniques, the areas of greater surface runoff can be identified so that buffer widths can be increased to reduce the hydraulic loading. This analysis is best performed using a contour based terrain model. In a contour based terrain model, every segment of contour line has an associated upslope drainage area. This area divided by the length of the contour line is the specific catchment area. Although other factors such as slope, soil type and vegetative cover affect the rate of surface runoff, the catchment area is a major factor and one that can be easily and objectively determined. Because of its objectivity, it can be used as a design criterion for precisely delineating variable-width buffers that will be more effective than fixed-width buffers in improving the quality of stormwater runoff.