Catastrophic Collapse of Water Supply Reservoirs in Urban Areas

Abstract

In recognition of the risks associated with the catastrophic collapse of a water supply reservoir, a computer model was developed to predict the progress of the ensuing flood. The fractional-step method is used to solve the two-dimensional shallow water wave equations on an unstructured triangular grid. The finite-volume method with a first-order approximate Riemann solver is used to solve the homogeneous equations. Euler's method is used to solve the ordinary differential equation operator. Verification of the model is achieved by comparing the model results with analytical solutions as well as documented published results with very good agreement. The model is applied to a case study involving the sudden collapse of a water supply reservoir. These reservoirs are generally located in elevated positions in residential areas, and represent a potential risk to life and property. The model is conservative, robust, efficient, and capable of simulating the wetting and drying processes. It resolves shocks, simulates flow around complex geometry and obstacles, and includes the influence of steep bed slopes and friction.