Modelling preferred vehicle wash-down localities for reducing weed seed spread in Queensland
Weeds cost Queensland an estimated $500 million every year and have significant impacts on primary industries, natural ecosystems, and human and animal health. Vehicle movement from weed infested to non-infested areas is a major cause of weed seed spread. The establishment of Washdown Facilities (WDF) at strategic locations greatly reduces the potential for weed seed spread. WDF may also assist in maintaining compliance with legislative requirements under Section 46 of the Qld Land Protection (Pest & Stock Route Management) Act 2002. Whilst there are a number of wash-down facilities in place, it is recognised that there are additional areas where establishment of new wash-down facilities or upgrading of existing facilities would be of benefit in weed spread prevention now and in the future.
This project used a 2-stage suitability model in a GIS to locate the best potential wash-down sites in Queensland. The first stage extracted the most strategically suitable WDF sites using proximity to electricity, piped water and high-risk road networks. Sites were prioritised according to their effectiveness in preventing spread from infested areas into clean but very suitable areas for the weed. Key weeds associated with weed seed spread, such as Parthenium hysterophorus and weedy Sporobolus spp. were investigated. Sites that were most effective in protecting environmentally sensitive and economically productive areas were further prioritised. The second stage evaluated the suitability of each WDF site based on availability of suitable areas of public land that had 24 hour site accessibility, was close to major road networks but distanced from environmentally sensitive areas and cost-effective to build.
The 2-stage process of the model allows decision makers to prioritise strategically effective WDF sites, then to further to refine prioritisation and therefore maximise resources by identifying low-risk WDF sites.