Urban and Industrial Encroachment
Urban encroachment occurs when population growth and land values in cities and urban areas puts pressure to develop surrounding peri-urban and rural regions, which may contain high value agricultural soils. Industrial encroachment occurs when land becomes more economically valuable for industrial uses than other uses (for example, coal mining) (Williams 2015). The areas that urban and industrial developments encroach upon are often valuable in their current state or are were previously deemed unsuitable for urban development. Valuable soils include those used for agriculture, ecosystem services, and conservation, whereas unsuitable sites include floodplains and contaminated land (NSW EPA 2015, Metcalfe and Bui 2017). Urban encroachment is a serious global issue; two thirds of the world’s population is projected to be urban by 2050 (ITPS 2015). In addition to the agricultural benefits, preventing urban encroachment into peri-urban and rural areas also yields social benefits such as recreation, biodiversity, visual amenity, flood mitigation and other ecosystem services (Metcalfe and Bui 2017).
Due to the historic situation of Australian cities near soils suitable for horticulture and agriculture, and water, urban expansion into the peri-urban fringe has led to capping of these soils. It appears unlikely that these good-quality soils will ever regain their biological function (State of the Environment 2011 Committee 2011, Metcalfe and Bui 2017). Urban developments also affect yield and water regimes (Campbell 2008). Pressure to sell also affects nearby agricultural landholders as new occupants in the expanded urban area put pressure on growers to change or cease farming practices that cause odour, noise or dust (Metcalfe and Bui 2017). Urban encroachment causes an iterative loss of strategically valuable agricultural lands in local government areas and is a significant challenge across most states and territories (State of the Environment 2011 Committee 2011, Metcalfe and Bui 2017). Although urban encroachment occurs nation-wide, prevention against it occurs at local government and State levels through city boundaries and state development policies. Some states have introduced legislation to protect key soil-agricultural areas from urban encroachment (e.g. Barossa and McLaren Vale Character Preservation Bills in South Australia), but this is not the case for many other regions.
Campbell, A. 2008. Managing Australia’s soils – a policy discussion paper. Prepared for the National Committee on Soil and Terrain (NCST) through the Natural Resource Management Ministerial Council (NRMMC).
ITPS. 2015. Status of the world’s soil resources technical summary. FAO – Intergovernmental Technical Panel on Soils, Italy.
Metcalfe, D. J., and E. N. Bui. 2017. Australia state of the environment 2016: land. Australian Government Department of the Environment and Energy, Canberra.
NSW EPA. 2015. New South Wales State of the Environment 2015. New South Wales Environment Protection Authority, Sydney.
State of the Environment 2011 Committee. 2011. Australia state of the environment 2011. Independent report to the Australian Government Minister for Sustainability, Environment, Water, Population and Communities. DSEWPaC, Canberra.
Williams, J. 2015. Soils governance in Australia: challenges of cooperative federalism. International Journal of Rural Law and Policy Special edition 1:12.
Soil Science Australia acknowledges the traditional owners of the land and pays its respects to their Elders, past, present and future.