EVALUATION OF THE HYDRAULICS MODULE OF THE WQRRS MODEL FOR LOW FLOW SIMULATIONS

Abstract

The in-stream water quality model, Water Quality for River-Reservoir Systems, (WQRRS) was applied to a 68 kilometre section of the Bow River, much of which through the City of Calgary. Steady and unsteady low flow conditions were examined using four of the six different hydraulic routing methods contained in the Stream Hydraulics Package (SHP). The steady flow methods considered were simple backwater and stage flow. The unsteady flow methods considered were a finite element solution of the complete form of the St. Venant equations and the kinematic wave method. A sensitivity analysis was performed which examined variations of water surface elevations with changes in the number of channel cross-sections used to define the study section, the element lengths used in the discretization scheme of the study section, and the time step. The ability of the finite element solution of the St. Venant equations and the kinematic wave technique to simulate rapid changes in flow rate was also evaluated. The result...