ESEL Paper Review_20110911
 
By Hong Guo

1, Title and Author

Title: Implication of a kinematic wave model for first flush treatment design 

Authors:

Joo-Hyon Kanga, Masoud Kayhanianb, Michael K. Stenstroma,*

a Department of Civil and Environmental Engineering, University of California Los Angeles, CA 90095-1953,USA
b Department of Civil and Environmental Engineering, Center for Environmental and Water Resources Engineering, University of California, Davis, CA 95616,USA

2. Summary of Paper

This paper uses a deterministic model to predict pollutant mass first flush and to utilize it for better design of best management practices (BMPs) that focus on treating the first flush.  The model used the kinematic wave equation to calculate flow and mass transport, and erosion equations to calculate pollutant concentrations, which were assumed to be from a short and a long term source.
1, First flush simulations:  the author uses the COD parameter for the MFF simulations. Representatively, MFF20 was selected as the representative MFF ratio and investigated as the function of watershed length under the different conditions.
2, Relationship between MFF and site and rainfall conditions.
   This paper shows that different combinations of rainfall intensity and duration change hydraulic conditions, resulting in different emission rates of pollutants. 
1.    Higher rainfall intensity and longer duration produce larger MFF20 and WLopt(optimum watershed length).
And also, the bed slopes increases, WLopt becomes shorter. For this case, the MFF20, max proportionally increases as the slope increases although the increments were small in the simulated slope range (0.01-0.06).
2.    Smaller Kp(hydraulic conductivity of the pavement) produces larger MFF20.and shorter WLopt MFF20,max also decreases as Kp increases.
3.    Larger   yelds larger MFF20 and WLopt.   strongly affects the MFF20 in larger watersheds.
4.    Higher  (erosion coefficient of pollutant from the shorterm source) produces greater MFF20 but smaller WLopt. 
3, Implications for BMP design.
   Contours of watershed length generated by a family of MFF simulations can be used in determining locations and number of storm-drain inlets to maximize the first flush for highway BMPS.

3. Contribution:
In this paper, the author a deterministic model and mainly use the COD parameters for simulating the first flush in the highway in the Los angles in California. And more, he used the Saint-Venant equation to reduce the kinematic wave equation by neglecting local acceleration, convective acceleration and pressure force effects. This is the transport phenomena area that helps me review the knowledge again. I think it is a very good paper to the first flush research because this paper show us very exactly model for the highway landuse and give idea of the kinematic wave model for the first flush design