POSTER: Get a (Nutrient) Load of Lake Trafford!
Research Mentor: Dr. Edwin Everham
Additional Authors:
Abstract:
Freshwater lakes and other bodies of water are formidable and self sustaining, but an overload of nutrients can throw these lake systems off balance. Surface runoff originates from nonpoint sources such as runoff from “urban land uses, agriculture, silviculture, and mining; discharges from failing septic systems; and atmospheric deposition” (Kang & Gilbert, 2008). Land use surrounding Lake Trafford include commercial/industrial purposes and residential uses (Kang & Gilbert, 2008). Disturbances such as storms also impact runoff rates and can either decrease or increase nutrient loading, based on how stormwater is managed (Doyle & Miller, 1980). My model focuses on how land-use, stormwater treatment and storm events, and dredging all affect the amount of nutrients there are in Lake Trafford. The main concerns with Lake Trafford have to do with how harmful algal blooms have been affected the life in the lake and adjacent to the lake. I made the connection that runoff from industrial and agricultural practices have a role in the nutrient loading of Lake Trafford. When constructing this model, I decided on the “nutrient content” as the main stock and the “nutrient inflow” as the influx and “nutrient outflow” as the outflux. The auxiliaries contributing to the inflow are “land-use change (urbanization and agriculture)” and “stormwater discharge treatment.” In the paper by Kang and Gilbert (2008), it was determined that when stormwater is treated, this process removes 65% of total nitrogen (TN) and total phosphorus (TP) from entering Lake Trafford. I implemented this data by having this affect the “land-use change” auxiliary. The auxiliaries contributing to the outflow include dredging which would remove about 90% of TN and TP from Lake Trafford. The auxiliary connecting to both the inflow and outflow is “storms” which is the stochastic element of my model. Storms in theory could cause both an increase of nutrients and decrease of nutrients. This is because when a lake overflows during a storm event, some runoff and nutrients are removed in this process. I decided to manipulate the frequency of storms, frequency of dredging, and the presence of stormwater discharge treatment to determine how Lake Trafford would look like after 50 years. The data collected concluded that the best outcome would be to dredge every 10 years for the for the lowest amount of TN and TP after 50 years.