Year

1998

Degree Name

Doctor of Philosophy

Department

Department of Civil and Mining Engineering

Abstract

The aim of the thesis is to determine values of the rainfall losses and calibration parameter urban catchments using the upgraded version of the Watershed Bounded Network Model, WBNM Version 2.10. A related part of the study is to determine if WBNM is correctly modelling both the pervious and impervious areas within a catchment and if it is correctly modelling the catchment's watercourse sections.

The thesis contains a detailed description of runoff routing models, the way in which they model rural and urban catchments, and the hydrologic principles which they use. These include RAFTS-XP, RORB and WBNM . The urban stormwater model ILSAX was also reviewed.

The principles the models use to calculate runoff from rainfall are very similar. Catchment and rainfall data are entered into the computer for each subcatchment. Appropriate rainfall losses are then subtracted from the rainfall data. The excess rainfall is routed through the overland flow surface, which is also known as storage routing. From this procedure, the model calculates a runoff hydrograph at the outlet of the subcatchment. As this runoff hydrograph travels through the next subcatchment, the computer model routes it through the channel section. Storage routing and channel routing can either be linear or nonlinear. Additionally, the upstream hydrograph can be lagged through the channel section by a specified time. Time lagging of a hydrograph is only applicable when the subsidence of the hydrograph peak is not significant.

Comments

Accompanying disc can be consulted with the hard copy of the thesis in the Archives Collection, call no. is 551.480994/8

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