Gully erosion in sub-tropical south-east Queensland, Australia

Abstract

Analysis of aerial photographs shows that gully erosion in three catchments in south-east Queensland, Australia, was initiated by post-European settlement. Analysis of historical rainfall and runoff showed that for two of the catchments, gully initiation occurred during wet decadal periods. Historical descriptions of the settlement of south-east Queensland and Moreton Bay detail significant changes in landuse and clearing of vegetation for grazing of domestic animals and urban development since 1842. Historical gully erosion rates varied from 14 to 1826 m2 yr- 1 and erosion rates are positively correlated with catchment area multiplied by slope. Analysis of gully erosion rates showed a linear increase in planemetric area over time. Together, these data show gully initiation in the three catchments is associated with post-European settlement land use practices and above average rainfall and runoff. Initiation of gullying across the region is similar to the previous studies in south-east Australia and highlights the sensitivity of the landscape to vegetation clearing and alternating periods of above average rainfall and drought.