Abstract Soil erosion is a serious issue in Australia and this paper attempts a continental synthesis of erosion, fluvial sediment transport and sediment delivery to the coast. Continental soil erosion is estimated to be 28 X 10 9 t year 1 of which about 50% is from sheet and rill erosion and the remainder from gully and river channel erosion. The rill and sheet erosion is 19% of Pimentel's global estimate from 5% of the world land area. Modern rates of erosion have increased by a factor of up to 145 compared to the natural rates before human disturbance. River transport rates are relatively low due to inefficient sediment delivery in keeping with the arid and low lying nature of the continent. Much of the river sediment is derived from gully sources and while sheet and rill erosion are high, little of this material is delivered to rivers. The modern flux to the oceans is about 302 X 10 6 t year 4 or 2% of the estimated global flux (Milliman & Syvitski, 1992) which appears approximately double that pre-human disturbance. The continental sediment delivery ratio is 3%. INTRODUCTION It is a curiosity that in a country where soil erosion is said to be a serious issue for agriculture, water resources, and the coastal environment (Commonwealth SoE Report, in press; State of the Marine Environment Report, 1995) there have been few attempts to provide a quantitative national summary of the phenomenon. There have been several earlier reviews of erosion data (Olive & Walker, 1983; Loughran, 1984 and Rieger & Olive, 1988) but these are now dated and have not really attempted a continental scale synthesis. In this brief paper, we note the nature of available data, present partial syntheses, draw conclusions arising from some of these syntheses, and at the continental scale make comparisons with global summaries. Many of the approximations in this paper should be considered only as starting points for further refinements.
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