If you made any changes in Pure these will be visible here soon.

Personal profile

Research engagement

Research student supervision

Tim has extensive experience with higher degree research students, having supervised to completion 1 PhD, 7 MRes and 2 Honours students as primary supervisor; and 2 PhD and 4 MRes students as associate supervisor.

Current PhD and MRes candidates:

  • Neda Yousefi (PhD project: Channel bifurcation and adjustment in multi-channelled floodplain wetlands)
  • Bradley Graves (PhD project: Channel discontinuity and floodout formation in dryland rivers)
  • Sana Khan (co-supervised PhD project: Analysis of river sensitivity for setting ‘expectations’ of geomorphic adjustment for river management)
  • Megan Gomes (PhD project, cotutelle with University of the Witwatersrand, South Africa: The geomorphology and avulsion history of the Mara River and floodplain wetlands in the semiarid Northern Province, Tanzania)
  • Carl Helander (MRes project: The role of chemical sedimentation in floodplain gigai development in the Macquarie Marshes)
  • Christoph Langenmaier (MRes project: Predicting global threats to wetlands in drylands)


Tim’s research focuses on the geomorphology of rivers and wetlands in dry landscapes. He has worked extensively in the Murray-Darling Basin in Australia, and in Africa (Tshwane-Pienaars River, South Africa; Okavango Delta, Botswana; Nile River, Egypt). His research seeks to understand patterns and processes of fluvial landform change, sediment dynamics, aquatic ecosystem function, and interactions between people and rivers/wetlands in the context of long-term landscape evolution and environmental change. Tim collaborates widely with national and international colleagues, and is a key member of the Wetlands in Drylands Research Network.

Tim is recognised internationally for fluvial geomorphology research and coordination roles in training and capacity building programs for assessment of soil erosion and sediment transport using nuclear techniques, with the International Atomic Energy Agency (IAEA). He is Lead Country Coordinator for the IAEA Regional Cooperative Agreement Project RAS5084 “Assessing and Improving Soil and Water Quality to Minimize Land Degradation and Enhance Crop Productivity Using Nuclear Techniques” from 2018-2021.

Prior to his academic appointment, Tim was a senior environmental scientist with the NSW government (now DPIE) where he conducted and managed scientific projects, and worked closely with environmental managers to link river and wetland research to decision-making efforts and policies. This work led to publication of the book “Floodplain Wetland Biota in the Murray-Darling Basin: Water and habitat requirements” and continues through co-funded research, engagement and outreach with DPIE and the NSW National Parks and Wildlife Service.


Community engagement

Research interests

  • River channel, floodplain and wetland morphodynamics
  • Fluvial responses to environmental variability and climate change
  • Sedimentology, geochronology and palaeoecology
  • Sediment tracing and sediment dynamics in catchments
  • Patterns, rates and hydrogeomorphic controls on aquatic ecosystem metabolism
  • Wetland responses to inundation; water and habitat requirements of freshwater biota
  • Links between fluvial and environmental change and human settlement in ancient civilisations
  • Anthropogenic impacts on environmental systems

External positions

Senior Environmental Scientist

20 Aug 200823 Mar 2010

Environmental Scientist

20 Aug 200719 Aug 2008

Environmental Scientist

2 Sep 200630 Sep 2006

Fingerprint Dive into the research topics where Tim Ralph is active. These topic labels come from the works of this person. Together they form a unique fingerprint.

  • 24 Similar Profiles

Network Recent external collaboration on country level. Dive into details by clicking on the dots.

Research Output

A shifting ‘river of sand’: The profound response of Australia's Warrego River to Holocene hydroclimatic change

Larkin, Z., Ralph, T. J., Tooth, S. & Duller, G. A. T., 17 Aug 2020, In : Geomorphology. 370, 107385.

Macquarie University

Research output: Contribution to journalArticleResearchpeer-review

  • Future aridification and the response of Australia's dryland rivers

    Larkin, Z. & Ralph, T. J., 27 May 2020, OzeWEX.

    Macquarie University

    Research output: Contribution to specialist publicationArticleResearch

    Open Access
  • Application of feature selection methods and machine learning algorithms for saltmarsh biomass estimation using Worldview-2 imagery

    Rasel, S. M. M., Chang, H. C., Ralph, T. J., Saintilan, N. & Diti, I. J., 11 Jun 2019, In : Geocarto International. 25 p.

    Research output: Contribution to journalArticleResearchpeer-review

  • Soil carbon dynamics and aquatic metabolism of a wet-dry tropics wetland system

    Agnew, D., Fryirs, K., Ralph, T. J. & Kobayashi, T., 8 Oct 2019, (Submitted) In : Wetlands Ecology and Management.

    Research output: Contribution to journalArticleResearchpeer-review

  • The Okavango River: past, present, and future?

    Larkin, Z. T., Ralph, T. J., Tooth, S. & Fryirs, K. A., 2018. 1 p.

    Research output: Contribution to conferenceAbstractResearch

    Open Access