Overview
Simulating algae blooms with a hydrodynamic-water quality model is challenging because it requires a thorough understanding of physical and biological processes and involves numerous parameters. This study conducted a sensitivity analysis of the EFDC+ hydrodynamic and water quality model for simulating cyanobacteria growth, an important harmful algal bloom (HAB) species, in the Ohio River, USA.
Model Setup
The sensitivity analysis assessed 23 model input parameters, divided into nine functional groups according to their characteristics. The assessment analyzed the impact of changing these input parameters on four water quality model outputs: algae (cyanobacteria), dissolved oxygen, total nitrogen, and total phosphorus.
Key Findings
Light extinction parameters, maximum algal growth rate, and algal base metabolism were identified as the most sensitive parameters for simulating algal growth, while solar radiation required for algal growth was moderately sensitive. Because few studies simulate HAB dynamics in riverine systems, this work deepens understanding of HAB development in rivers with lock and dam structures that create a series of pools along the river. Future work will focus on the sensitive parameters in model calibration.