Water quality modeling of a eutrophic drinking water source: Impact of future climate on Cyanobacterial blooms
Journal article, 2023

Cyanobacterial blooms are becoming more frequent in freshwater sources, causing concern throughout the world. Cyanobacterial blooms affect human health and the entire environment. Numerical modeling is an effective tool for investigating aquatic systems. In this study, a 3D hydrodynamic and water quality (ecological) model was used to simulate eutrophication of a drinking water source, Lake Vomb, in Sweden under present and future scenarios. The hydrodynamic model was set-up in MIKE 3 FM software based on meteorological, hydrological, and water quality data. The hydrodynamic model performance was satisfactory in terms of the water temperature simulation, with root-mean-square-error (RMSE) ranging from 0.38 to 1.2 °C. In the ecological model, Chlorophyll-a (Chl-a) was used as a proxy for Cyanobacteria, and the model proved acceptable in simulating the Chl-a concentrations, with a Nash-Sutcliffe efficiency (NSE) of 0.93 and 0.87 for calibration and validation respectively. The findings revealed that external nitrogen loading and internal phosphorus loading had significant impact on the nutrient concentrations in Lake Vomb. The findings also showed a correlation between Chl-a levels and total phosphorus levels in the lake. To simulate future water quality in the lake, two Representative Concentration Pathways (RCP) for the year 2050 were used to make projections for changes in air temperature and precipitation. Under the projected future climate, the simulations showed a considerable rise in Cyanobacteria biomass independent of the changes in external nutrient loading. The model findings can assist water managers in planning mitigation strategies by identifying major nutrient sources.

Climate change

Process-based modeling

Blue-green algae

Nutrient loading

Chlorophyll-a

Hydrodynamic model

Author

Ahmed Elhabashy

Chalmers, Architecture and Civil Engineering, Water Environment Technology

Uppsala University

Jing Li

Lund University

Ekaterina Sokolova

Uppsala University

Chalmers, Architecture and Civil Engineering, Water Environment Technology

Ecological Modelling

0304-3800 (ISSN)

Vol. 477 110275

Subject Categories

Water Engineering

Oceanography, Hydrology, Water Resources

DOI

10.1016/j.ecolmodel.2023.110275

More information

Latest update

1/30/2023