Wind erosion and land management in eastern Australia during two great droughts; the World War II Drought (1937-1946) and the Millennium Drought (2001-2010).
1, Tadhg O'Loingsigh2, Katherine Parsons2, Grant McTainsh2, John Leys3
1Fenner School of Environment and Society, Australian National University, Canberra, ACT, Australia, 2Griffith School of Environment, Griffith Un, Brisbane, QLD, Australia, 3NSW Office of Environment and Heritage, Gunnedah, NSW, Australia
Unravelling the influences of drought and land management on wind erosion rates is challenging because both drivers vary through time and space. One way to understand the extent to which land management accelerates wind erosion is to quantitatively compare wind erosion episodes which occurred in contrasting land management regimes. Because land management in Australia has significantly improved through time, comparison of the wind erosion during an early period, with poor land management, with a more recent period of improved management, offers the best opportunity to demonstrate the positive influence of good land management upon wind erosion rates.
In this study quantitative measurements of wind erosion activity in eastern Australia during the late 1930s-1940s and the 2000s to examine the question of whether the contrasting wind erosion activity during the World War II Drought (1937-1946) and the Millennium Drought (2001-2010) was due to differences in the severity of the two droughts, or due to differences in land management. Initially, spatially-averaged levels of wind erosion activity are quantitatively compared between the two droughts in relation to drought severity. Then spatial variations in wind erosion activity are compared to the drivers of land management as identified through literature review.
Our results show that wind erosion activity for eastern Australia was 2.78 to 4.65 times higher during the WWII Drought than during the Millennium Drought. Measures of drought intensity (Standardised Precipitation Index) however indicates that on average the Millennium drought had a greater impact. Review of land management drivers during the two periods revealed fundamental changes across five main management themes; community awareness, government policy on land management, agricultural/pastoral practices, pest management and land use change. These land management drivers are not unique to Australia and by understanding the changes can be used to drive further change across managed lands worldwide.