Model Library

Capabilities

• Hydrodynamic and water quality processes in both stratified and non-stratified systems, including interactions among nutrients, dissolved oxygen, and organic matter, are modeled;
• Features encompass fish habitat analysis, selective withdrawal from stratified reservoir outlets, hypolimnetic aeration, and multiple biological groups like algae, epiphyton/periphyton, zooplankton, and macrophytes;
• The model incorporates sediment diagenesis (Version 4), generic water quality groups, and an internal dynamic model for pipes and culverts;
• It also supports algorithms for hydraulic structures such as weirs and spillways, including submerged and two-way flow scenarios, and a dynamic shading algorithm based on topographic and vegetative cover.

Limitations

• It is complex and time-consuming (Ejigu, 2021);
• It does not simulate multiple species for phytoplankton (Ohio Environmental Protection Agency, n.d.);
• The model is not capable of simulating the possible localized water quality change resulted from development activities in the watershed (Ohio Environmental Protection Agency, n.d.);
• It simplifies lateral and vertical variations, reducing data needs but potentially limiting accuracy under significant accelerations (Wells, 2024);
• Its laterally average equations make variations in temperature, velocities, and concentrations insignificant, resulting in being less suitable for large waterbodies (Costa et al., 2021);
• The hydrostatic assumption is not satisfied in all fluid motion scenarios (Arefinia et al. 2020);
• The equations describing the algal processes are oversimplified, compromising the model accuracy to simulate the algal growth (Costa et al. 2019);
• The model does not incorporate Zooplankton, Sediment Oxygen Demand and metals (Zouiten et al. 2013).

Inputs

Geometric data, Bathymetric data, Initial conditions, Boundary conditions, Hydraulic parameters, Kinetic parameters, - The CE-QUAL-W2 model takes inputs in the form of various organic matter (OM) pools, multiple algae species, biochemical oxygen demand (BOD), and epiphyton groups (Debele et al., 2008).

Outputs

Water balance, water level, time series concentrations of conservative and non-conservative constituents, water quality over depth profile.

References

Zhang, X., Luo, X., Huang, W., Tan, B., Hu, P., Xia, Z., Haffner, G. D., Taylor, W. D., Long, L., Ji, D., Zhang, Y., & Zhang, L. (2023). Unique physical processes of canyon reservoirs regulate the timing and size of algal blooms: Based on a study in Three Gorges Reservoir. Journal of Hydrology, 621, 129662. 
https://doi.org/10.1016/j.jhydrol.2023.129662

Liu, C., Qu, L., Clausen, J., Lei, T., & Yang, X. (2023). Impact of riparian buffer zone design on surface water quality at the watershed scale: A case study in the Jinghe Watershed in China. Water, 15, 2696. 
https://doi.org/10.3390/w15152696

Objectives

The objectives of the study were to test hypotheses about the role of the surface density layer (SDL) in regulating the timing, size, and duration of algal blooms in a canyon reservoir, and to quantify the relationship between the SDL and algal bloom dynamics in order to improve understanding of how hydrological processes can be modified to manage harmful algal blooms.

This paper aimed to answer two questions: (1) Is the coupled model applicable in the study of reservoir water temperature and water quality variations? (2) What are the key factors of the distribution of the water temperature, water quality and pollutant transport and transformation in river-type reservoirs?