Evaluating Urban Pollutant Buildup/Wash-Off Models Using a Madison, Wisconsin Catchment

• Published in: Journal of environmental engineering (New York, N.Y.) Vol. 136; no. 2; pp. 194 - 203
• Main Authors: Shaw, Stephen B, Stedinger, Jery R, Walter, M. Todd
• Format: Journal Article
• Language: English
• Published: Reston, VA American Society of Civil Engineers 01.02.2010
• Subjects: Applied sciences; Biological and physicochemical phenomena; Catchments; Construction; Continental surface waters; Exact sciences and technology; Freshwater; Kinetic energy; Mathematical models; Natural water pollution; Parametrization; Pollution; Rainfall; Rainwaters, run off water and others; Regression analysis; Storms; TECHNICAL PAPERS; Water treatment and pollution; USA, Wisconsin; USA, Wisconsin, Madison; Storm; Catchments; Urban area; Parameterization; Modeling; Nexrad Levell II Data; Rain; Watershed; Stormwater management; Kinetic energy; Wisconsin; Buildup/wash-off models; Urban areas; Prediction; Watersheds; Regression analysis; Runoff water; Hydrology; Pollutant; Nonpoint source pollution; Surface water; Water pollution; Storm water; Urban hydrology; Reflectance
• ISSN: 0733-9372; 1943-7870
• DOI: 10.1061/(ASCE)EE.1943-7870.0000142

Buildup/wash-off (BUWO) models are widely used to estimate pollutant export from urban and suburban watersheds. Here, we propose that the mass of washed-off particulate during a storm event is insensitive to the time between storm events (the traditional predictor of particulate accumulation in BUWO models). Our analysis employed USGS data of total suspended solids and discharge data for nonsnow events in a 9.4 -km2 suburban catchment in Madison, Wis. Kinetic energy of rainfall was calculated using National Weather Service NEXRAD radar reflectivity. A regression analysis found that storm event runoff volume and rainfall kinetic energy explained 81% of the variability in event particulate load; volume alone explained 69% of the variability in event loads. Time between storm events was not significant. Additionally, we simulated storm event particulate loads using a BUWO model and a model assuming a constant mass available for wash-off. Both models produced very similar predictions over a range of parameterizations, suggesting that buildup models could perhaps be simplified under many circumstances.