# EFDC+ Enhancements

# Propeller Wash

EEMS10.3 provides a fully integrated propwash module that predicts bottom velocities, bed shear and sediment resuspension using ship information, position, and speed that dynamically couples to the three-dimensional hydrodynamics of the waterbody. Optionally, the propeller energy can be incorporated into the three-dimensional flow field behind the ships. The EEMS propwash module is a game changer for contaminated sediment remediation sites where ship traffic and associated propwash impacts are observed. This update will also allow more integrated propwash assessments for port and harbor engineers evaluating foundation and bulkhead impacts due to propeller action and harbor maintenance dredging. Learn more (opens new window)

Animation of Propwash Module GUI and Ship in San Diego Harbor

# Unlimited Algal Groups

The EFDC+ eutrophication model has been refactored and enhanced to allow for defining of a general phytoplankton group. Users will now be able to simulate an unlimited number of algal and periphyton groups, with each group assigned different settling, half-saturation constants, uptake rates for nutrients, etc., according to the aquatic ecosystem conceptual model. This feature boosts EEMS so to it can better capture the extreme diversity of phytoplankton and improves the accuracy of the computation of algal biomass. Learn more (opens new window)

Vertical Profile View of Simulation of Eutrophication in Pearl Lake with Unlimited Algal Groups

# Unlimited Zooplankton Groups

Zooplankton play a significant role in water body nutrient dynamics as grazers that control both algal and bacterial populations. They also serve as a food source for higher trophic levels and in the excretion of nutrients. Understanding the role of zooplankton in the distribution and flux of nutrients in the aquatic system is important for effective management. A module for zooplankton kinetics has been implemented in EDFC+ version 10.3, based primarily on the formulation provided in Cerco and Noel (2004). The model defines a general group for the purpose of simulating an unlimited number of zooplankton groups. The role of zooplankton in water-column respiration and in nutrient recycling is represented by the interfacing of the zooplankton component with the other eutrophication state variables. This development was supported by ongoing collaboration with professor Dongil Seo from Chungnam National University, South Korea. Learn more (opens new window)

Zooplankton Study on Lake Thonotosassa

Zooplankton Study on Lake Thonotosassa

# Oil Wind Shear

EFDC+ has been upgraded to include wind shear for oil spills. EEMS already simulates the movement of oil spills, including advection, spreading, dispersion and evaporation. The wind shear on oil spills at the surface of the water has been found to be linearly proportional to the wind speed. Using results of these studies, EFDC+ includes a modified empirical formula to improve forecasting of the movement of oil slicks on waterbodies. Learn more (opens new window)

Oil Wind Shear Options in EEMS10.3 GUI

Oil Wind Shear Options in EEMS10.3 GUI

# EFDC_Explorer Enhancements

# Online Background Maps

EE can now load and display online background maps for any location on earth. The used maps are open source and provided by MapServer. This functionality greatly improves the user experience with EEMS as externally generating background maps is no longer necessary. This feature will also be available in a completely rebuilt CVLGrid that will be available sometime after the release of EEMS10.3. Learn more (opens new window)

Demonstration of How to Use Online Background Maps in EEMS10.3

# Improved Wind Wave Options

The interface for the internally coupled and external wave models has been streamlined. Options for using the external SWAN wave model have been updated to allow for new and improved configuration options. The overall GUI for setting the wind-wave interactions is now considerable simplified.

Streamlined GUI for Wind Wave Module

Streamlined GUI for Wind Wave Module