Morphological Impacts and Implications of a Trial Release on the Wingecarribee River,New South Wales

A trial, monitored release on the Wingecarribee River over 27 days had a peak discharge below the Wingecarribee Dam of 1090 ML/d, which had a flow duration of 0.95 per cent. Morphological impacts on 29 km of channel below the dam included bank erosion, concentrated neck overflow, bed degradation and channel widening at recent cutoffs, sedimentation in weir pools and overbank flow, particularly at discharges greater than 800 ML/d. Prolonged operational releases at bankfull discharge (400–800 ML/d) will have the greatest morphologic impacts and should be avoided. Pulses which dissipate stream power over a broad, well-vegetated floodplain should be incorporated in the operational release policy, provided such pulses are phased to facilitate channel and vegetation recovery.     

Estuarine Acidification: Impacts on Aquatic Biota of Draining Acid Sulphate Soils

Acid sulphate soils form when iron pyrite oxidises to sulphuric acid on atmospheric exposure, lowering soil pH below 4. In the Richmond River estuary, northern New South Wales, flood mitigation, drainage works and floodplain excavations have augmented acid sulphate soil formation by increasing pyrite availability for oxidation. These engineering works have facilitated the transport of acidified water and have impeded recovery from tributary acidification. The increased frequency and duration of acidification are associated with elevated concentrations of inorganic monomeric aluminium and dissolved iron, and major iron hydroxide precipitation, with deleterious effects on exposed aquatic biota and habitat. Fish kills and an outbreak of epizootic ulcerative syndrome (EUS) have been recorded from acidified sites in the estuary.     

The Kuriles: the Geo-political Spanner in the Geo-economic Works

The sovereignty of the bleak Kurile islands, off northern Japan, has long been the subject of a bitter stand-off between Russia and Japan. This has not only prevented their signing a post-1945 Peace Treaty but has retarded the flow of official financial assistance and corporate investment funds across the few hundred kilometre-wide Sea of Japan. As a result the reconstruction of the Russian Far East has been made more difficult, thus exacerbating the economic and social hardship there. Examples like this should cause us to reflect on the dangers of making simplistic explanations about the spatial organisation of economic activity as well as the need to rediscover political geography.