Application of a 3D Model to Simulate Water Quality in a Stormwater Pond

• Author / Creator

  Mehdizadeh, Mahyar

• The coupled three-dimensional hydrodynamic and water quality ELCOM-CAEDYM model was used to investigate the factors impacting the abundance of algae as a key indicator of water quality in a stormwater pond in the city of Edmonton, Canada. Field measurements collected from May to October of 2014 and 2015 were used to set up the model and to calibrate the model. The inflow time series, as an important boundary condition, was estimated using the reverse level pool routing method with low-pass filtering of the observed water level time series. Both analytical and Monte Carlo simulations showed that errors in the estimated inflows are directly related to the area of the pond and inversely related to the numerical time step.
  ELCOM was calibrated and validated for water temperature. The model accurately simulated the thermal structure of the pond including mixing and stratification. Sensitivity analysis of ELCOM showed that the model is most sensitive to albedo. Sensitivity analysis showed that the most influential CAEDYM model parameters were, the maximum potential growth rate, algal respiration, mortality and excretion rate, minimal internal phosphorous concentration, and light half saturation constant for algae limitation. Total chlorophyll-a (TCHLA) was found to be the most sensitive model variable and as a result CAEDYM was calibrated and validated, primarily focusing on TCHLA, while also considering other state variables such as dissolved oxygen, total phosphorous, and total nitrogen.
  Furthermore, the sensitivity of ELCOM-CAEDYM to the boundary conditions and depth was comprehensively assessed. For this, different scenarios were defined by altering flow rates, nutrient loads, air temperature, wind speed, and depth, and their corresponding impacts on different biogeochemical and hydrodynamic processes were evaluated. The trophic state of the pond under these scenarios was also assessed. Given that ELCOM-CAEDYM effectively simulated algae dynamics, as demonstrated through calibration and validation, and considering its responsiveness to changes in boundary conditions, it can be used as a tool to predict water quality under future climate and management plans.
  KEYWORDS: ELCOM-CAEDYM, sensitivity, reverse level pool routing, water quality, stormwater pond.

• Subjects / Keywords

  • ELCOM-CAEDYM
  • Reverse level pool routing
  • Water Quality
  • Stormwater Pond

• Graduation date

  Fall 2024

• Type of Item

  Thesis

• Degree

  Doctor of Philosophy

• DOI

  https://doi.org/10.7939/r3-5etp-x461

• License

  This thesis is made available by the University of Alberta Library with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.