How to use this survey
Inventory and condition surveys can help people in the pastoral industry to plan for the sustainable use of natural resources and the protection of those areas suffering from degradation or at risk of degradation.
The Murchison River Catchment survey was undertaken between 1985 and 1988 by PJ Curry, AL Payne, KA Leighton, P Hennig and DA Blood. The department published this survey in 1994 as Technical bulletin 84 'An inventory and condition survey of the Murchison River Catchment, Western Australia'.
The survey reports identify and describe the condition of soils, landforms, vegetation, habitat, ecosystems, and declared plants and animals. They also report on the impact of pastoralism and make land management recommendations, including estimated carrying capacities for each pastoral lease.
The department has surveyed and reported on 14 rangeland areas since 1972. Most of the rangeland pastoral leases have been surveyed, except for leases in the Southern Goldfields region and to the north-east of Wiluna-Meekatharra. The 15th rangeland survey — in the Southern Goldfields region, covering the area known as the Great Western Woodlands — is in progress and will be published in 2018.
Survey area and inventory summary
The area surveyed by field work during 1985-88 covers about 88 360 square kilometres of arid zone rangelands situated between Mount Magnet and Meekatharra in the east, and the catchments of the Greenough and Wooramel rivers in the west.
The survey area includes most of the catchment of the Murchison River and its tributaries - the Sandford, Roderick and Yalgar rivers, as well as most of the catchment of Lake Austin.
The flora of the area is diverse, with about 830 recorded vascular species, of which 97% are native and about 4.5% are endemic or near-endemic.
Species have been objectively classified and described as 23 major types. All but 3 of these are shrublands or low woodlands, of which most are naturally lacking in grasses. Mulga (Acacia aneura) and cotton bush (Ptilotus obovatus) are ubiquitous perennials.
The survey report provides condition statements for the whole survey area and for each land system. Pasture and soil condition was assessed at a number of points throughout the survey area. Findings include:
- 21% of points were in good to very good rangeland condition
- 37% were in fair rangeland condition
- 42% were in poor to very poor rangeland condition.
Overall, the report data indicates that vegetation condition in this survey area is poorer than other rangeland areas in Western Australia.