Science, Technology and Engineering

Environmental Geoscience

Postgraduate Projects

Water balance modelling and quantification of salt storage, transport and discharge in the Mt. William Creek sub-catchment of the Upper Wimmera region using hydrogeological, chemical and isotopic techniques

Matt Edwards

Supervisor: Dr John Webb

The agricultural productivity, surface water quality and tourism potential of the Wimmera catchment in western Victoria, is threatened by increasing salinity problems. My research identified and characterised the processes leading to the development of salinisation in the high-salt-yielding Mount William Creek sub-catchment, using a suite of physical and chemical techniques. This will allow land and water authorities, such as the Wimmera Catchment Management Authority and the Department of Primary Industries, to make the most informed decisions about how the salinity problem within the catchment should be managed. The research has generated some significant findings including the identification of the ultimate origin of the salt and the timescales and mechanisms of its accumulation in the landscape; the identification of areas where large volumes of recharge are entering the groundwater system, contributing to elevated watertables; the delineation of groundwater flow paths, inter-aquifer interactions and surface water-groundwater interactions, and how these contribute to the salinity problem; and the identification of the unsaturated zone a medium for significant chemical evolution of soil waters and groundwaters, which may have implications for other groundwater systems.

The project is supported by the Wimmera Catchment Management Authority. The research was co-supervised by Phil Dyson of Phil Dyson and Associates.