Experiments on Urban Flooding Caused by a Levee Breach

Abstract

Breached levees often cause extensive flood damage to urban and residential areas; there has been considerable interest in the numerical modeling of flooding of urban areas in recent years. However, comprehensive data that describe the complex flow field in residential areas are not available for validating the numerical models or for determining the extent of such damage. To fill this gap, results are presented of experiments on a scale model used as a test setup that examined the flow field in an urban area attributable to flooding caused by a levee breach. Steady state flow depths and flow velocity were measured by a point gauge and by an array of ultrasonic velocity profilers, respectively. In addition, the surface velocities were recorded in the entire flooded area by using a digital particle tracking velocimetry technique. The details of these measurements, limited flow data, and the observed flow characteristics are presented in this study. Full data sets are provided on the Internet. The results of these investigations show that closely spaced buildings act like a single obstacle with a common wake zone, and there is little flow between these buildings. The results also show that the strongest flow is in the prebreach direction and that the local topography plays an important role in distributing the flow in the flooded area. The complete data set may be utilized to validate numerical models of free surface flow.