School of Geography and Environmental Science
Monash University, Victoria 3800
McTainsh and Boughton (1993) remarked that causes of land degradation can be natural, such as the bushfires, droughts and floods initiated by climatic factors, whilst others including the use of fire by Australian Aborigines and poor farming practices by European settlers are directly attributable to human activities. They classified land degradation into three main types with the major subtypes listed in parentheses; soil erosion and deposition (water and wind erosion), soil degradation (soil salinity and degradation of soil structure) and ecosystem change (degradation of vegetation). A recent assessment of the status of various types of land degradation in Victoria was made in the 1991 State of the Environment Report entitled `Agriculture and Victoria's Environment' (Commission for the Environment, 1992), whilst an introduction to the historical geography of land degradation in this State is provided by the research of Powell (1975; 1976; 1989).
What appears to be one of the earliest examples of accelerated (ie. man-induced) land degradation in Victoria following European settlement was reported by John G. Robertson in a letter to Lieutenant-Governor Charles La Trobe dated 26 September, 1853. The letter, part of which is reproduced below, referred to land in the Casterton and Coleraine areas of southwestern Victoria.
|"Many of our herbaceous plants began to disappear from the pasture land; the silk-grass began to show itself in the edge of the bush track, and in patches here and there on the hill. The patches have grown larger every year; herbaceous plants and grasses give way for the silk-grass and the little annuals, beneath which are annual peas, and die in our deep clay soil with a few hot days in spring, and nothing returns to supply their place until later in the winter following. The consequence is that the long deep-rooted grasses that held our strong clay hill together have died out; the ground is now exposed to the sun, and it has cracked in all directions, and the clay hills are slipping in all directions; also the sides of precipitous creeks-long slips, taking trees and all with them. When I first came here, I knew of but two landslips, both of which I went to see; now there are hundreds found within the last three years.|
A rather strange thing is going on now. One day all the creeks and little watercourses were covered with a large tussocky grass, with other grasses and plants, to the middle of every watercourse but the Glenelg and Wannon, and in many places of these rivers; now that the only soil is getting trodden hard with stock, springs of salt water are bursting out in every hollow or watercourse, and as it trickles down the watercourse in summer, the strong tussocky grasses die before it, with all others. The clay is left perfectly bare in summer. The strong clay cracks; the winter rain washes out the clay; now mostly every little gully has a deep rut; when rain falls it runs off the hard ground, rushes down these ruts, runs into the larger creeks, and is carrying earth, trees, and all before it. Over Wannon country is now as difficult a ride as if it were fenced. Ruts, seven, eight, and ten feet deep, and as wide, are found for miles, where two years ago it was covered with tussocky grass like a land marsh. I find from the rapid strides the silk-grass has made over my run, I will not be able to keep the number of sheep the run did three years ago, and as a cattle station it will be still worse; it requires no great prophetic knowledge to see that this part of the country will not carry stock that is in it at present..."(Bride, 1898, 168-9).
|"War has come to Australia. The danger is real indeed but, I say it deliberately, not more real than the insidious threat by an enemy we have had with us for years. We can, and will, repel the foe now hammering our frontiers-we are eager and willing to enter the lists against him ; but we are actually encouraging and assisting this other enemy, civilization's greatest menace, soil erosion."|
|An early map of the incidence and hazard of wind and water erosion in Victoria was prepared from information supplied by the Soil Conservation Board and published in 1944. Sheet, rill, gully and tunnel erosion and concomitant siltation were marked as were the locations of landslides, stream erosion and siltation and drift sand. Briefly, drift sand accumulations were recorded in the Mallee and various types of water erosion were observed in the uplands, the hazard for erosion by wind and water respectively being acute in both areas.|
Soil Erosion - State Regional Boundaries Committee (1944) (PDF 337KB)