REVEGETATION OF DAMAGED BANKS AND SHORELINES ALONG INLAND WATERWAYS

摘要

The health of numerous Australian rivers and estuaries has been seriously degraded over time with the loss of bank vegetation, worsening erosion and ecological impacts being of major concern. The main factors that generally contribute to vegetation loss and bank erosion are direct vegetation removal, scour and slumping associated with flood events, grazing and trampling by animals and wave action generated by wind or boats. Frequently boat traffic is blamed. Although natural reseeding of vegetation can occur, it is generally sporadic and dependent upon a wide range of environmental factors including soil, water level, wave exposure, weather (previous and current), water quality and plant fertility. Controlled replanting can accelerate the rate and success of revegetation, however the success rate of present procedures is not high nor predictable. Minor wind or boat waves action is known to be detrimental to the success of revegetation planting in the critical spring growth season. Full scale controlled laboratory wave flume testing has been undertaken to examine the wave erosion resistance of various planting options including "seedlings", "tubestock", "cuttings" and "rhyzome clumps" on different bank slopes. The results of the laboratory testing will be reported. Practical techniques for reliable large scale revegetation planting will be presented.