School of Plant Biology

Alexandra Rouillard

Thesis

Reconstructing extreme hydroclimatic variability in semiarid northwest Australia

Summary

The Pilbara region of northwest Australia is characterized by extreme climatic variability, where prolonged droughts are punctuated by highly dynamic flooding events resulting from low-pressure systems forming in the region. Current research suggests the northwest is experiencing less frequent but more extreme cyclones. However, these changes are based on limited and relatively recent observations and need to be placed in context against long-term (centuries to thousands of years) climate patterns.

My research will apply a range of interdisciplinary paleolimnological techniques and remote sensing to investigate the frequency and intensity of extreme hydroclimatic variability over the inland Pilbara over the recent historical past through the Holocene (last ~10,000 years).

Why my research is important

A key problem for reducing the uncertainty in climate projections is historical records of change are too short to test the skill of climate models, raising concerns over our ability to successfully plan for future change. My research will provide the first paleolimnological records from northwest Australia and thus contribute to improve both spatial and temporal resolution of past environmental changes across the region. My approach will test and implement both novel and more broadly used analytical techniques used in the study of sediments, such as stable isotopes, biomarkers and community analysis, and potentially provide the first fundamental knowledge on primary sources of sedimentary carbon in arid Australia. My findings will also contribute to increased understanding of the hydrogeologic evolution of groundwater within the region.

Funding

• International Postgraduate Research Scholarship (IPRS)
• Australian Postgraduate Award (APA)
• Natural Sciences and Engineering Research Council of Canada (NSERC) Postgraduate Scholarships (PGS)
• Fonds de recherche du Québec - Nature et technologies (FQRNT) - Bourse de doctorat en recherche (B2)
• ARC Linkage project (LP120100310) between UWA and Rio Tinto