NATURAL VERSUS ACTIVE REHABILITATION OF SEISMIC LINES INTHE COOPER BASIN

Abstract

Extensive investigations undertaken in the Cooper Basin during the 1980s reveal that seismic lines prepared in dunefield and floodplain land systems rehabilitated naturally within a reasonable timeframe. It also appeared, however, that lines prepared in the dissected residual and gibber plains land systems would persist virtually indefinitely without active intervention. The principal issues were identified as being the ongoing aesthetic impacts of rocky windrows, ongoing expansion of erosion gullies and scars on hillsides and escarpments.

Subsequently, an extensive seismic line restoration program was undertaken in gibber land units, in which graders were used to respread windrows over seismic lines, to install erosion control structures at the head of active gullies and to batter the edges of small erosion gullies. In general, the program was highly successful in reducing the visual impact of seismic lines and speeding the rehabilitation of small gullies.

Active rehabilitation of large erosion gullies and scarred escarpments was not attempted, as it was considered that the process would be very expensive and would result in only marginal aesthetic improvements. Subsequent investigations have revealed that the lateral erosion and slumping of erosion gullies will, within a reasonable timeframe, result in the gullies resembling natural drainage features as revegetation occurs and the linear connection with the restored seismic line on the adjoining footslopes disappears.