Temporal distribution of storm rainfall on the Witwatersrand and its effect on peak flows.
Date
1991
Authors
Cross, Anthony Leighton
Journal Title
Journal ISSN
Volume Title
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Abstract
The temporal distribution of rainfall can have a
significant effect on peak runoff, especially so in the
small catchments that are typical of the Witwatersrand.
This report investigates the shape of the natural
hyetoraph and its use in the analysis of peak runoff.
It describes the climatology of the sub-continent and
rain-producing systems. Then more specifically,
aspects of rainfall over Johannesburg are discussed.
Some Of the more commonly-used temporal distributions
of rainfall are reviewed and the relationship between
intensity-time distributions and mass curves is
illustrated.
Mass curves are derived using data from a rain gauge in
Norwood, Johannesburg. The data is analysed with the
assistance of a computer program and classified into
quartiles. The quartiles are further analysed in an
attempt to define their characteristics in greater
detail.
The mass curves are used wIth a hydrological model to
generate hydrographs. The values of runoff peaks are
found to be comparable with those obtained using
currently accepted temporal rainfall distributions.
Description
A project report submitted to the Faculty of
Engineering, University of the Witwatersrand,
Johannesburg, in partial fulfilment of the requirements
for the degree Of Master Of Science in Engineering.
Keywords
Hydrology -- Research -- South Africa -- Transvaal., Depth-area-duration (Hydrometeorology), Climatology -- Research -- South Africa., Rain and rainfall -- South Africa -- Transvaal.