Oral Presentation Australian Society for Limnology Conference 2016

How unusual is the Big Dry? Evidence from the Victorian Lakeland (#22)

Keely Mills 1 , Peter A Gell 2 , Peter Kershaw 3
  1. British Geological Survey, Keyworth, Nottinghamshire, UK
  2. Federation University Australia, Ballarat, VIC, Australia
  3. Monash University, Clayton, Victoria, Australia

Lakes respond to changing hydroclimate through changes in lake level which induces changes in water chemistry, habitat availability and so to biota. The fossilised evidence of different lake conditions are archived in the sediments which accumulate through time. The Victorian Lakeland is among the most intensively studied regions of the world in terms of paleoecology. Long term records from these lakes show great hydroclimatic variability, including multi-decadal droughts, in the past. Some records show drought to have been a major factor in switching lake condition before the arrival of Europeans. However, the Big Dry appears to be a significant event at centennial, and even millennial, timescales and most lakes are now at the margins, or outside, their long term range of variability. This is consistent with observations of the anomalous state of the Southern Annular Mode and suggests that the Lakeland is on a trajectory towards a drier future.

Mills, K., Gell, P., Doan, P., Kershaw, A.P., McKenzie, M., Lewis, T. & Tyler, J. (under revision). Evidence for a drought-driven (pre-industrial) regime shift in an Australian shallow lake. The Holocene.

Mills, K., Gell, P. & Kershaw, P. 2013. The Recent Victorian Drought and its Impact: Without Precedent? Rural Industries Research and Development Corporation Publication 12/040. 77pp.

Barr, C., Tibby, J., Gell, P. Tyler, J., Zawadzki, A. & Jacobsen, G. (2014). Climatic variability in southeastern Australia over the last 1500 years inferred from the fossil diatom records of two crater lakes. Quaternary Science Reviews, 95: 115-131.