Watershed Modelling of BMP Effects on Water Quality in Three Southern Ontario Watersheds

Session: 41b. - Great Lakes Harmful Algal Blooms Research from Watershed Influence to Ecosystem Effects

Yongbo Liu, Department of Geography, University of Guelph, [email protected]
Wanhong Yang, Department of Geography, University of Guelph, [email protected]
Hui (Shawn) Shao, Department of Geography, University of Guelph, [email protected]
John Lindsay, Department of Geography, University of Guelph, [email protected]

Abstract

From 2015 to 2017, Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA) and Ontario Soil and Crop Improvement Association (OSCIA) jointly implemented the Great Lakes Agricultural Stewardship Initiative (GLASI). Field monitoring and watershed modelling were conducted to evaluate existing and newly-established BMPs in the study areas. This presentation reports the modelling achievements and findings for three of the six GLASI watersheds, Gully Creek (14.5 km²), Garvey Glenn (16.0 km²), and Upper Medway (19.3 km²). Based on available climate, topography, soil, land use and management, and monitored flow and water quality data, the SWAT (Soil and Water Assessment Tool) model was adapted and applied to examine the effectiveness of a suite of BMPs including water and sediment control basins (WASCoBs), grassed waterways, cover crops, controlled tile drain, nutrient management, tillage management, and many others on water quantity and water quality at both field and watershed scales. Modelling results showed that the effectiveness of BMPs was considerably different across the three watersheds due to landscape and BMP differences. Significant pollutant reductions were found at the edge-of-field. However, the magnitudes of BMP effectiveness at watershed outlet were not pronounced for some of the BMPs due to relatively small application areas.  

1. Keyword
modeling

2. Keyword
water quality

3. Keyword
Great Lakes basin

4. Additional Keyword
Agricultural BMPs

5. Additional Keyword
SWAT