Perth Laboratory – Public Seminar Series 2007

Impacts of regional drainage, climate change and revegetation on water and salt in the Avon basin

Riasat Ali and Geoff Hodgson
Groundwater Hydrology
Irrigation and Water Resources Program
CSIRO Land and Water | Water for a Healthy Country Flagship

Thursday 29 October 2007 at 3.30pm, CSIRO Auditorium

Abstract

Western Australia has the largest area of dryland salinity in the nation and the highest risk of increased salinity in the next 50 years, with the annual cost of its consequences estimated to be more than $600 million. About 25–30% of the Avon basin, the largest of all in the wheatbelt, may develop shallow water tables and will be at risk of salinisation in the future. One form of combating dryland salinity is through engineering solutions such as deep open drains. Within the last decade this form of salinity mitigation has increasingly become popular and the construction of farm and subcatchment scale drainage systems has increased significantly in the Avon. The drainage discharge from most of these drainage systems is currently being disposed into natural creek/river systems potentially causing adverse ecological and hydrological impacts to these systems. This project, the first of its kind in the wheatbelt of WA, evaluated various subcatchment and regional scale drainage management strategies and assessed their hydrological and economic feasibility.

The LASCAM hydrological model was calibrated for the Avon basin and used to investigate, under do nothing conditions, the impacts of current and future salinity on streamflows and salinity of the river systems over the next 100 years. The impacts on streamflows and salt loads from several drainage, climate change and revegetation scenarios were assessed and compared against the do nothing case. The modelling tool developed can now be applied to examine the impacts of proposed regional drainage projects on downstream environments and determine the optimal discharge management strategy, and ultimately the feasibility of various forms of drainage proposal.

About the speaker

Riasat Ali completed his PhD at Oklahoma State University, USA in 1993. He then worked in the International Waterlogging And Salinity Research Institute (IWASRI), Lahore, Pakistan before joining CSIRO Land and Water in 1997. Over the last 10 years he has worked on and led a number projects national and international projects on engineering solutions to dryland salinity; irrigation and drainage management; soil salinity modelling; geochemical modelling; and simulation-optimisation techniques.

This talk results from a collaborative project with Neil Viney, Geoff Hodgson, Warrick Dawes and Aryal Santosh from CSRIO and John Ruprecht, Ken McIntosh and David Rowlands from the Department of Water, WA and Richard George from the Department of Food and Agriculture, WA. The project was funded by Engineering Evaluation Initiative of the WA State Government and Water for a Healthy Country Flagship.

PowerPoint Presentation
(3.4 MB)

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