OJCE  Vol.5 No.3 , September 2015
Easy-to-Use Look-Up Hydrologic Design Charts of a Soak-Away Rain Garden in Singapore
ABSTRACT
As catchments become urbanized due to population growth the impervious surfaces created by buildings and pavements in the expense of permeable soil, depressions, and vegetation cause rainwater to flow rapidly over the landscape. To mitigate the adverse impact of urbanization such as increased flooding and depleted groundwater recharge, around the world, several best management practices, in other words, green infrastructures have been practised, and soak-away rain garden is one of them. However, to have a rapid assessment of soak-away rain gardens on a range of potential hydrologic conditions (e.g., size of the soak-away rain garden, saturated hydraulic conductivity of the in-situ soil, and saturated hydraulic conductivity of the filter media), hydrologic design guidelines or design charts of soak-away rain gardens that are specific for local conditions are not currently available for many regions including Singapore. Thus, in this paper, with a design hyetograph of 3-month average rainfall intensities of Singapore, hydrologic design charts, especially, design charts on overflow volume (as a % of total runoff volume) of soak-away rain gardens are established for a range of potential hydrologic conditions by developing a mathematical model based on Richard’s equation using COMSOL Multiphysics, a finite element analysis and solver software package for various physics and engineering applications. These easy-to-use look-up hydrologic design charts will be of great utility for local managers in the design of soak-away rain gardens.

Cite this paper
Mylevaganam, S. , Chui, T. and Hu, J. (2015) Easy-to-Use Look-Up Hydrologic Design Charts of a Soak-Away Rain Garden in Singapore. Open Journal of Civil Engineering, 5, 269-280. doi: 10.4236/ojce.2015.53027.
References
[1]   Allan, P.D., Robert, G.T. and William, F.H. (2010) Improving Urban Stormwater Quality: Applying Fundamental Principles. Journal of Contemporary Water Research and Education, 146, 3-10.
http://dx.doi.org/10.1111/j.1936-704X.2010.00387.x

[2]   Jia, L., David, J.S., Cameron, B. and Yuntao, G. (2014) Review and Research Needs of Bioretention Used for the Treatment of Urban Stormwater. Journal of Water, 6, 1069-1099.
http://dx.doi.org/10.3390/w6041069

[3]   Hunt, W.F., Jarrett, A.R., Smith, J.T. and Sharkey, L.J. (2006) Evaluating Bioretention Hydrology and Nutrient Removal at Three Field Sites in North Carolina. Journal of Irrigation and Drainage Engineering, 132, 600-608.
http://dx.doi.org/10.1061/(ASCE)0733-9437(2006)132:6(600)

[4]   Jones, M.P. and Hunt, W.F. (2009) Bioretention Impact on Runoff Temperature in Trout Sensitive Waters. Journal of Environmental Engineering, 135, 577-585.
http://dx.doi.org/10.1061/(ASCE)EE.1943-7870.0000022

[5]   Li, H., Sharkey, L.J., Hunt, W.F. and Davis, A.P. (2009) Mitigation of Impervious Surface Hydrology Using Bioretention in North Carolina and Maryland. Journal of Hydrologic Engineering, 14, 407-415.
http://dx.doi.org/10.1061/(ASCE)1084-0699(2009)14:4(407)

[6]   Richards, L.A. (1931) Capillary Conduction of Liquids through Porous Mediums. Journal of Applied Physics, 1, 318-333.
http://dx.doi.org/10.1063/1.1745010

[7]   COMSOL AB (2012) COMSOL Multiphysics User’s Guide (Version 4.3). Stockholm.

[8]   COMSOL AB (2012) COMSOL Multiphysics Reference Guide (Version 4.3). Stockholm.

[9]   Li, Q., Ito, K., Wu, Z., Lowry, C.S. and Loheide II, S.P. (2009) COMSOL Multiphysics: A Novel Approach to Ground Water Modeling. Groundwater, 47, 480-487.
http://dx.doi.org/10.1111/j.1745-6584.2009.00584.x

[10]   Chow, V.T., Maidment, D.R. and Mays, L.W. (1988) Applied Hydrology. McGraw Hill, New York.

 
 
Top