Ecohydrology Seminar: Dr. Franck Lespinas

Friday, August 11, 2017 11:30 am - 11:30 am EDT (GMT -04:00)

Simulating mercury dynamics in Canadian terrestrial catchments using a physically-based ecohydrological model

Presented by: Dr. Franck Lespinas

Concerns about mercury (Hg) pollution have risen markedly in the last decades because of global human health and environmental risks. Mercury can be converted by microbial communities in aquatic environments into methylmercury (MeHg), a potent neurotoxin, that bioaccumulates up the food web and leads to subsequent ingestion of Hg-contaminated fish by humans and piscivorous wildlife. Fish in a large number of rivers across Canada contains high levels of MeHg which is the leading cause of most of the fish consumption advisories. Environment and Climate Change Canada (ECCC) has recently adapted a physically-based ecohydrological model developed by US Environment Protection Agency (EPA), The Visualizing Ecosystems for Land Management Assessments (VELMA) model, to simulate and study mercury cycling in diverse Canadian forested watersheds under the Canadian Mercury Science Program framework. VELMA links hydrological and biogeochemical processes within watersheds to simulate the cycling of water, carbon, nitrogen and mercury in plants and soils, and the transport of dissolved forms of carbon, nitrogen and mercury from the terrestrial landscape to the streams. A modeling framework combining VELMA and an automatic parameter optimization method, the Dynamical Dimensioned Search Algorithm (DDS), was developed. The model was applied to simulate the hydrology and biogeochemistry of nutrients and Hg in two boreal forested catchments in Canada. The model, optimization strategy, and results as well as future prospects for the study will be presented.