Eutrophication Studies

DSI developed a linked watershed and water quality model spanning 1,400 square miles of the Caloosahatchee watershed to support FDEP’s TMDL process. The estuary, listed among Florida’s impaired water bodies, receives nutrient-laden inflows from Lake Okeechobee along with agricultural runoff and urban discharges. The model simulates algal blooms, dissolved oxygen dynamics, and nutrient cycling to inform restoration planning. See also Demo model (DM-23).

EFDC+ was used to model sediment, nutrient, and heavy metal dynamics in Lake Taihu, one of China’s largest and most heavily eutrophic lakes. The study examined contaminant exchange between the water column and the sediment bed, contributing to the scientific understanding of this internationally significant water body.

EFDC+ was applied to Daoxiang Lake to simulate eutrophication and forecast algal blooms, using chlorophyll-a concentration as the key indicator and 2008 field data for calibration. The study demonstrated EEMS as a proactive tool for managing bloom risk in urban lakes across Asia.

After a toxic algal bloom struck the Han River in 2015, EFDC+ was used to model bloom dynamics along a 71 km reach using a 2D approach, with chlorophyll-a as the principal variable. The application showcased EEMS’s value for early warning and protective water management in dense urban river systems. See also the free grid.

EEMS was used to model the Little Bow River across the full chain from flow through nutrient cycling to aquatic plant dynamics, including rooted plants and epiphytes. The comprehensive calibration supported both regulatory assessment and long-term planning in this agriculturally impacted watershed.

DSI built a linked HSPF–EFDC+ model to support TMDL development for Tenkiller Ferry Lake, which was listed as impaired due to elevated nutrient levels. A 20-year watershed simulation generated the flow and nutrient loads driving the water quality model, providing the EPA with a robust technical basis for evaluating load reduction scenarios.

Lake Mendota has served as a benchmark site for EEMS water quality capabilities, with demonstrations spanning cyanobacteria behavior, turbulence, thermal dynamics, water quality calibration, and ice formation. These validated applications showcase the breadth of the EFDC+ water quality toolkit.

EEMS was applied to West Lake to simulate water quality, including toxin dynamics and wind-wave interactions. A real fish die-off event provided validation data, demonstrating that EEMS supports both emergency response and longer-term water management in Asian urban lakes. Demo models: DM-05 (Toxics) and DM-03 (Windwave).