Development and testing of a fast conceptual river water quality model

Area of Science:

• Environmental Engineering
• Water Resource Management
• Computational Fluid Dynamics

Background:

• River water quality management relies on complex hydrodynamic and water quality models.
• Detailed, physically-based models are computationally intensive, limiting long-term analysis and scenario testing.

Purpose of the Study:

• To develop a faster, yet accurate, conceptual river water quality model.
• To overcome the computational limitations of detailed water quality models.

Main Methods:

• A structure identification method was used to create a conceptual model.
• River branches were divided into conceptual reservoirs (Plug Flow Reactor and Continuously Stirred Tank Reactor).
• Advection-diffusion and water quality processes were modeled with adjusted residence times.

Main Results:

• The conceptual model achieved a computational speed-up factor of 10^5.
• Significant reduction in calculation time without substantial loss of accuracy.
• Feasibility of performing time-demanding scenario runs and analyses.

Conclusions:

• The developed conceptual modeling approach offers a computationally efficient alternative for river water quality management.
• This method enhances the practicality of detailed statistical analysis and sensitivity studies.
• Enables more robust and frequent water quality assessments and decision-making.