Modelling of Road Salt Influences on Surface Waters: Application of SWAT to Harp Lake, Ontario

Session: 35. - Watershed Modeling across all Scales from Small to Large

IBRAHIM RASHID, Trent University, [email protected]
April James, Nipissing University, [email protected]
Huaxia Yao, ON Ministry of Environment and Climate Change, [email protected]

Abstract

Winter de-icing of roads with salt has led to increases in concentration of chloride in lakes with debilitating impacts on aquatic organisms. In-lake, streamflow, precipitation and chloride concentrations have been monitored at Harp Lake, a small inland Canadian Shield lake near Huntsville ON along with weather conditions for over 35 years. Observations show increases in chloride concentration in Harp Lake, its outflow, and some inflows located downstream of road crossings. In this study, we explore the capability of Soil and Water Assessment Tool (SWAT) to quantitatively simulate chloride concentrations in Harp Lake and its catchment. SWAT is a physical-based distributed model that can be used to simulated water quality and quantity at various scales, and includes the ability to model both point and non-point source pollution.  Although SWAT is generally applied to large watersheds, it had been validated for smaller scales and has been specifically tested at Harp Lake. Despite the extent of road salt impact and the importance of water quality modelling, there is a lack of direct application of SWAT to road salt analysis. Current exploration focuses on adapting SWAT to simulate NaCl and lake chloride concentrations using a surrogate point source variable such as NO3- .

4. Additional Keyword
Road salt; Chloride concentration, Harp Lake, Canadian Shield

5. Additional Keyword
SWAT model

6. Additional Keyword
Point source variable