Estimating Phosphorus Load Reductions using the Soil and Water Assessment Tool

Session: Applications of Simulation Models in Watershed Science and Lake Ecology (1)

Aisha Javed, University of Toronto Scarborough, [email protected]
Alex Neumann, University of Toronto Scarborough, [email protected]
Feifei Dong, University of Toronto, [email protected]
Dong-Kyun Kim, University of Toronto Scarborough, [email protected]
Agnes Richards, Environment Canada, [email protected]
Shan Mugalingam, Lower Trent Conservation, [email protected]
George Arhonditsis, University of Toronto Scarborough, [email protected]

Abstract

Eutrophication caused by excessive phosphorus (P) loading from agricultural lands is an on-going environmental concern that is affecting aquatic ecosystems worldwide. The development of robust watershed models is critical in our efforts to accurately estimate phosphorus loads and effectively design best management practices (BMPs). Here, we present a modelling study that primarily focuses on the Napanee, Wilton Creek and Hay Bay watersheds located in the Bay of Quinte Area of Concern, where emerging evidence suggests that the nutrient contributions are significantly higher than what has been historically assumed, and may modulate the frequency of harmful algal blooms in the receiving waterbody. Through the development of an ensemble of Soil and Water Assessment Tool (SWAT) models, calibrated with Bayesian inference techniques, this study will evaluate different BMP scenarios and address important questions, such as: What is the impact of disturbances associated with intense summer storm events on system stability? What is the likelihood that land use management practices will alleviate the impact of these episodic events? The anticipated insights into the ability of hydrological extremes to modulate the response of integrated watershed-receiving waterbody systems will offer critical planning information for the local decision-making process.