Cover condition of the Beetaloo region

Abstract

The Beetaloo GBA region in the Northern Territory of Australia currently supports a modest gas extraction industry. With the possibility of a significantly expanded industry in the future, it is important to understand the current environmental impacts of the industry. Towards this end, this analysis examines the effects of current gas extraction activities on vegetation cover condition in the Beetaloo GBA region. It does this using the Compere relative benchmarking framework, which has been parameterised here to use ground cover fraction data (which is an excellent proxy for landscape condition) and to separate-out the variability in ground cover associated with natural processes from the variability associated with human activities. Results show that gas extraction wells and gas pipelines had significant negative effects on cover condition at their immediate locations compared to vegetation in the surrounding 1 km of land. Beyond distances of 1 km, pipelines seemed to have no further effect on condition whereas at distances between 1 and 4 km from wells, condition was found to be significantly lower than at the well location itself. The reasons for this are not known. Given that only minimal extraction activities currently occur across the Beetaloo GBA region, this study provides a baseline assessment against which future analyses could be compared if the industry is further developed.

Attribution

CSIRO

History

Six input datasets were used to define biophysical equivalence (locations of similar growing conditions): precipitation, burned area; elevation, available water holding capacity, and long-term average tree foliage cover fraction. Precipitation data were from the monthly data of Jones et al. (2009). Burned area data (MCD64A1, Collection 6) were from Giglio et al. (2009); elevation from Gallant et al. (2011); water holding capacity from Viscarra Rossel et al. 2014 and tree fractional cover were based on the methods of Donohue et al. (2009). Cover condition was assessed using total cover fraction data of Guerschman et al. (2015), which is based on MCD43A4 C6 imagery. Surface Water Points data were used to test results and were sourced from Crossman and Li (2015).

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