Determination of Infiltration Parameters for Urban Flood Modeling

Vol. 1 No. 3

Year: 2011

Issue: Jun-Aug

Title: Determination of Infiltration Parameters for Urban Flood Modeling 

Author Name: Sanat Nalini Sahoo, Sreeja 

Synopsis: 

The tremendous growth of infrastructure has reduced the precipitation accommodating capacity of urban areas. This has magnified the runoff volume and peak flow there by aggravating the flooding condition. So for an efficient flood management strategy to be followed, the infiltration process has to be modeled effectively and thus the runoff should be accurately predicted. For modeling of infiltration process the infiltration parameters are normally determined through model calibration or field measurements. In this study the infiltration rate of a locally available sandy soil has been obtained by using tension infiltrometer. Various infiltration parameters like steady state flows, saturated and unsaturated hydraulic conductivities and sorptivity at different suction heads were then derived. The tests have been conducted with different degree of compaction and saturation to recreate the natural field condition of the total urban catchment. The unsaturated hydraulic conductivity of the soil was found out to be 0.00104cm/sec and 0.00016cm/ sec for suction head of 10cm and 20cm respectively for an oven dried soil of dry unit weight of 1.48gm/cc. Since most of the infiltration models need one or more of the above mentioned infiltration parameters, the details obtained from this study would be quite helpful for flood modeling, by incorporating realistic infiltration characteristics of the catchment.