An improved equation development for longitudinal dispersion coefficient

Area of Science:

• Environmental Science
• Hydrology
• Water Quality Monitoring

Background:

• The longitudinal dispersion coefficient (D_l) is crucial for assessing river assimilatory capacity.
• Existing models may not fully account for the impact of suspended and dissolved solids on D_l.

Purpose of the Study:

• To develop an improved equation for the longitudinal dispersion coefficient.
• To investigate the influence of total suspended solids (S_s) and total dissolved solids (D_s) on D_l.

Main Methods:

• Incorporated S_s and D_s into a new model for D_l.
• Compared the developed equation's accuracy against existing methods (Seo and Cheong).
• Evaluated model performance using statistical metrics like SE, NME, and MME.

Main Results:

• The developed equation demonstrated high accuracy, with 100% of estimated D_r values falling within the acceptable range (0.0 to 0.3 or -0.3 to 0.0).
• S_s and D_s were found to reduce the magnitude of D_l values.
• The new model outperformed the Seo and Cheong method, which achieved 93.3% accuracy.

Conclusions:

• The improved equation provides a more accurate estimation of the longitudinal dispersion coefficient.
• Accounting for S_s and D_s enhances the understanding of riverine processes and water quality assessment.
• The derived equation is adequate for estimating D_l, supporting effective river management.