Empirical watershed models for delineating hot-spots of nutrient export

Session: Poster session

Alex Neumann, University of Toronto Scarborough, [email protected]
Feifei Dong, University of Toronto, [email protected]
Dong-Kyun Kim, University of Toronto Scarborough, [email protected]
Yuko Shimoda, University of Toronto Scarborough, [email protected]
George Arhonditsis, University of Toronto Scarborough, [email protected]

Abstract

The recent dramatic reappearance of harmful algal blooms (HABs) in Western Lake Erie Basin has highlighted the role of phosphorus (P) from non-point sources (NPS). Despite the overall reduction of P loading to Lake Erie from 28 KT yr^-1 in 1968 to 6-12 KT yr^-1 in 2000s, NPS has been identified as one of the primary culprits of HABs. Nonetheless, the uncertainty about the actual NSP contribution to the total P loading prevents a consensus among stakeholders on the optimal loading reduction from diffuse sources. In this context, watershed modelling is considered a useful analysis tool to quantify exogenous phosphorus loading associated with watershed attributes, including land uses and morphological characteristics. Simple empirical watershed models can be particularly useful to offer first approximations of annual estimates of nutrient loads, yields, and deliveries at landscape and regional scales. A characteristic example is the SPAtially Referenced Regressions on Watershed attributes (SPARROW); a statistically parameterized non-linear model with contaminant supply and process components, including non-conservative transport, mass-balance constraints, and surficial flow paths defined by topography, streams, and reservoirs. Our study presents the strengths of this model and highlights the benefits of its use in the context of adaptive management implementation in Lake Erie. 

1. Keyword
watersheds

2. Keyword
phosphorus

3. Keyword
Lake Erie