Monday, March 9, 2009

Reading #7

Perez-Pedini C, Limbrunner JF, Vogel RM (2005) “Optimal location of infiltration-based best management practices for storm water management,” JOURNAL OF WATER RESOURCES PLANNING AND MANAGEMENT, 131(6) pp. 441-448.

Summary:
Traditionally, stormwater has been controlled systems of detention basins. However, these structures are expensive to construct, so a growing trend is to use low impact development (LID) in the form of infiltration basins to curb runoff.

The Aberjona River watershed in Massachusetts was studied. The are was divided into 120 m X 120 m squares and elevations, land use, and flow paths were found for each cell using GIS. The NRCS curve number method was used to find the infiltration and runoff for each square during a specific event. The optimisation technique was setup so that each square would be represented by a binary variable representing whether the infiltration basin will be built there; if true, the CN for that cell would be decreased by five, representing an increase in infiltration. Then a genetic algorithm was used to find those cells which had the greatest impact on reducing the runoff. The algorithm was run several times with different numbers of infiltration ponds to develop a Pareto-optimal curve for infiltration ponds vs reduction in runoff.


Discussion:
I found that this article presented an interesting problem which was solved using genetic algorithms. The techniques used seemed logical, and the results seem to make sense. The methods presented in this article should be a valuable tool for community planners hoping to use infiltration ponds for flood control.

In the future, these methods should be used on a system consisting of detention and infiltration ponds, since almost no urban stormwater management systems are going to be completely infiltration. Also, a technique that can take into account how the pond affects runoff as well as water quality might be useful.

1 comment:

  1. You say "these methods should be used on a system consisting of detention and infiltration ponds, since almost no urban stormwater management systems are going to be completely infiltration." Well I wonder if perhaps a stormwater management system SHOULD be completely infiltration, since you mentioned earlier that these structures are expensive to construct. Yes, it would be good to use these methods in the future on a system consisting of detention and infiltration ponds in order to determine if perhaps using only infiltration ponds can offer a more inexpensive solution to peak flow reduction.

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