The dust liftoff index is based on soil moisture and wind speed. This determines the dust liftoff risk, which is categorised according to the following levels of dust liftoff index:
0 - 50: Low risk
50 - 80: Moderate risk
80 - 100: High risk
100+: Extreme risk
This index is an indicator of the potential for dust lift-off particularly from material stockpiles, exposed land and other erodible surfaces. The equation considers the wind speed at 10 meters, the soil moisture content and certain properties of the soil such as the wind-erodible fraction and the mass-size distribution of particles. When the soil is particularly bare and dry, strong winds increase the potential for dust lift-off. If significant values for this parameter are forecasted then proactive actions such as watering haul roads, wetting or crusting the stockpile can be undertaken to minimise the risks.