Anthropogenically-induced erosion in arid and semiarid Australia.

Abstract

Roughly one third of the Australian continent is arid and one third semiarid. These areas are sparsely settled, yet all are affected by human activities. Large areas are under pastoral lease, some are agricultural, and some are in mixed farming. Important ore deposits have been found in the desert and the search continues. Tourism is increasingly important. Vegetation has been cleared by accident or by design and paths, tracks, roads and railways constructed. Exotic plants and animals have been introduced. The land has been ploughed, the water table lowered here, but raised there, in the latter case resulting in widespread soil salinisation. These activities have rendered the land surface vulnerable to erosion. Accelerated soil erosion, most obviously in the form of gullying but more importantly sheet erosion, involving the stripping of the A-horizon, is widespread. Averitable epicycle of erosion (and deposition) is in train.