Wind erosion and dust
Wind erosion is the process where the wind moves soil particles from one place to another. It is a natural process that has played an important part in shaping our landscape. However, poor land management and drought conditions that reduce soil cover can make the effects of wind erosion much worse.
Wind erosion can cause the following problems:
- loss of soil
- exposure of new acid sulfate soil materials
- loss of nutrients for plants
- scalds (areas of bare, hardened ground that do not easily soak up water)
- reduced infiltration of surface water
- transported soil can bury equipment and infrastructure.
Wind erosion can affect people's health by creating large amounts of dust. The dust can also reduce visibility and even disrupt electricity supplies.
During times of drought, as the lakes dry out, wind erosion and dust can be serious issues around the Lower Lakes.
How can the effects of wind erosion be minimised?
Any soil cover can reduce the effects of wind erosion by preventing soil particles from becoming dislodged and mobile. Plants can bind soil and keep the soil moist, as well as reduce the risk of exposing acid sulfate soils in the area by encouraging bioremediation.
Soil cover can reduce the wind speed at ground level which traps soil particles. Planting ground cover and sedges can reduce the impacts of soil erosion around the Lower Lakes.
Soils with a rough surface are less likely to be affected by wind erosion because wind speed at ground level is slower and transported soil is trapped in the troughs. However, methods such as ploughing to roughen the ground surface disturb acid sulfate soil and so these methods cannot be used in the region.
Moving domestic grazing animals from an area before they remove vegetation is a good way to minimise the impact of wind erosion.
When large areas of lake bed were exposed, the Government of South Australia worked closely with local landowners to plant large areas of shallow-rooted annual grasses to cover bare soils along the shoreline of Lake Alexandrina and Lake Albert. If lake levels fall below sea level in the future, this method will be used again to reduce the impacts of wind erosion and dust.