## Electronic Theses and Dissertations

1993

Thesis

M.Sc.

#### Department

Civil and Environmental Engineering

Sklash, M. G.,

Geology.

CC BY-NC-ND 4.0

#### Abstract

The main objective of this investigation was to examine storm runoff generation in the Palata Creek watershed in eastern Swaziland. Specifically, a suite of natural isotopic, chemical and hydrometric methods were used to assess groundwater contributions to storm runoff. The Palata Creek watershed drains an area of 6.35 km$\sp2.$ It is underlain by a massive rhyolite formation which is locally weathered. The average hydraulic conductivity of the weathered rhyolite as determined from single well tests in shallow wells is $1.0\times 10\sp{-7}$ m/s. Soils in the catchment are generally thin, and range from sandy to silty clay. During this research, the study area and the whole of southern Africa were affected by the worst drought in years. There were only three significant rainfall events in the catchment during this study. Oxygen-18 concentrations in rainfall, baseflow and stormflow, as well as hydrometric data were used to determine groundwater contributions to storm runoff in the catchment. Baseflow chemistry and isotopic composition matched that of shallow groundwater. The variability in the oxygen-18 content between rainfall events was large and it generated small but significant fluctuations in the stream isotopic composition. Both the chloride and electrical conductivity data in the baseflow and shallow groundwater showed no dilution by the rain water. Intact, a flushing effect occurred in which the electrical conductivity and chloride increased during the hydrograph rise. This type of flushing effect made chloride and electrical conductivity unsuitable as natural tracers for the mass balance hydrograph separation. (Abstract shortened by UMI.)Dept. of Geology and Geological Engineering. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1993 .N594. Source: Masters Abstracts International, Volume: 32-02, page: 0568. Adviser: M. G. Sklash. Thesis (M.Sc.)--University of Windsor (Canada), 1993.

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