Application of a Two-Dimensional Model of Hydrodynamics to San Timoteo CreekFlood-Control Channel, California

摘要

The San Timoteo Creek, located in southern California, is a tributary of theSanta Ana River and drains portions of the San Bernardino and Riverside Counties. The existing creek has the capacity to protect the surrounding community from approximately a 20-year-frequency flood. The proposed channel improvements will provide a 100-year level of protection. The proposed channel design within the reach studied includes a sediment basin, a concrete weir followed by a converging sidewall chute, a compound horizontal curve, and a bridge pier. This study was initiated because there was concern as to the adequacy of a one-dimensional analysis of the flow conditions within the channel chute. A two-dimensional analysis was deemed necessary to evaluate the chute's influence on the flow conditions in the curve and the curve's impact on the flow conditions at the bridge. The two-dimensional, depth-averaged flow model, HIVEL2D, was used to simulate the flows in the high-velocity channel. This model was chosen because of its ability to simulate supercritical flow and capture shocks such as oblique standing waves. Simulation results indicated that the proposed San Timoteo Channel design and in particular, the San Timoteo Canyon Road bridge, will convey the design discharge (100-year-frequency event, 19,000 cfs) in an acceptable manner. Finite element, San Timoteo Creek, California, Flood-control channels, Shallow-water equations, Numerical models, Two-dimensional.