Pockets of small landholdings used for hobby farms and grazing are most susceptible to urban infill and industrial development, leaving larger horticultural and dryland farms for food production, according to Flinders University researchers.
A new spatial planning tool, based on maps of Adelaide and its surrounding areas, could be adapted and used in rapidly growing cities in Australia and overseas to improve urban planning and major infrastructure development, says Professor Andrew Millington, an expert in Geographic Information System (GIS) and land science at Flinders University’s School of the Environment.
“We’ve used this GIS mapping technique to draw up a vulnerability map of the Adelaide region. It shows a number of highly fragmented peri-urban areas which could be targeted for land development as the city grows,” Professor Millington says.
“According to our metrics of State Government data, there are several areas with marginal economic value which are most susceptible to development, including hobby farms to the south and north of Adelaide.
“They could be the focus of development in order to preserve those valuable and often more economically viable food production farming areas in the future.”
While smaller horticultural and livestock grazing land is increasingly falling prey to housing, roads and other development on Adelaide’s urban fringes, dryland farming, larger-scale horticultural enterprises and heritage-protected vineyards are generally less vulnerable.
Around Adelaide, the researchers identified several key areas currently most vulnerable to development, including:
- To the north of Adelaide – the Gawler Belt, north of Virginia and the western end of the new Northern Expressway, between Edinburgh and Virginia.
- To the south – the O’Halloran Hill-Black Rd and Kangarilla areas
- To the east – some patches around Mt Barker and the Littlehampton hills-face zone.
“The test of this technique would be to apply it to another city which is expanding rapidly to see the potential hotspots which could be rezoned to encourage industry and developers to concentrate on acquiring these areas,” Professor Millington says.
However, these peri-urban agricultural lands which are more vulnerable for fragmentation can be protected with community engagement and other support, says the lead researcher Suranga Wadduwage.
Major city urban planning to reduce urban sprawl would benefit from close examination of underutilised, less productive land over more valuable, capital intensive food and wine agricultural land.
Apart from the planning authorities, these peri-urban areas come under the radar of different stakeholder policy networks, such as primary production, NRM boards and conservation groups, Mr Wadduwage says.
“It is possible to take an alternative view and rally the support of these stakeholder networks in collective planning strategies.
“These landholdings subject to lower economic returns can have a sustainable and enduring future rather than be consumed by urban developments, which has irreversible consequences for a city’s future.”
The research paper, Agricultural land fragmentation at urban fringes: An application of urban-to-rural gradient analysis in Adelaide, by S Wadduwage, A Millington, ND Crossman, H Sandhu (Flinders University) has been published in Land Vol 6 Issue 2 – and online here.