Tim’s research focuses on the geomorphology of rivers and wetlands, particularly those in dry landscapes. He and his team work across Australia (e.g. Murray-Darling Basin), Africa (Botswana, Egypt, Tanzania, South Africa) and the USA (Arizona). This research seeks to understand patterns and processes of fluvial landforms, 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 of technical training programs for assessment of soil erosion and sediment transport using nuclear and isotopic techniques, with the International Atomic Energy Agency (IAEA). He is Lead Country Coordinator for the IAEA Regional Cooperative Agreement Project RAS5091 “Assessing and Mitigating Agro-Contaminants to Improve Water Quality and Soil Productivity in Catchments Using Integrated Isotopic Approaches" from 2022-2025.

Prior to his academic appointment, Tim was senior environmental scientist with the NSW government where he led scientific projects and worked closely with environmental managers and landholders to link research to decision-making efforts and policies. This work led to the book “Floodplain Wetland Biota in the Murray-Darling Basin: Water and habitat requirements” and continues through co-funded research, engagement and outreach with a range of agencies and other stakeholders.

• River channel, floodplain and wetland morphodynamics
• Sediment tracing and agro-contaminants in catchments
• Hydrogeomorphic controls on aquatic ecosystem metabolism
• Wetland responses to inundation
• Water and habitat requirements of freshwater biota
• Fire history and impacts on rivers and wetlands
• Anthropogenic impacts, river recovery and management
• Fluvial responses to environmental variability and climate change
• Links between fluvial and environmental change and human settlement in ancient civilisations

• ENVS1017 and ENVS6202 The Living Environment
• ENVS2266 Earth Surface Processes
• ENVS3238 Environmental Quality and Assessment
• ENVS8403 Science in Environmental Management

Tim has extensive experience as supervisor and mentor to >30 higher degree research (HDR) students, and is available to discuss options for Masters and PhD research projects.

Current MRes candidates:

• Ella Molloy: Channel avulsion and incision in floodplain wetlands
• Jessica Honor: Soil health and inundation response in floodplain wetlands
• Stephanie Ius (primary supervisor A/Prof. Paul Hesse): Palaeochannel evolution and adjustment due to declining discharge

Current PhD candidates:

• Carter Lybeck: Geoecological response of inland rivers to floods and restoration efforts
• Michael Rupić: Social science and on-ground implementation of Natural Flood Management
• Kei Prior: Source-to-sink assessment of sediment and charcoal from wildfires in wetlands at the river/estuary interface
• Levente Laczko (primary supervisor A/Prof. Paul Hesse): Hydrogeomorphic response of an inland distributary river system to Holocene climate change
• Nicholas Crameri (primary supervisor A/Prof. Emilie Ens): Geo-ecological evolution of Indigenous Arnhem Land floodplains: past, present and future
• Lin Wang (primary supervisor Prof. Kirstie Fryirs): Geomorphology of floodplains and wetlands for Natural Flood Management
• Jay Chauhan (primary supervisor Prof. Kirstie Fryirs): Geomorphological and hydrological assessment of Natural Flood Management
• Challis Pulotu (primary supervisor A/Prof. Emilie Ens): An ethnobiological study on climate change influence and wetland
  management by Indigenous People of Narran Lakes
• Camila Fernández Nion (primary supervisor A/Prof. Maina Mbui): Ecosystem risk from land-use and climate change in Uruguay’s coastal protected areas
• Eleuterio Abreu De Sousa (primary supervisor Dr Karin Sowada): Adaptive responses to environment, climate, and socio-political agents in animal management during the Late Holocene: Neolithic and Early Bronze Age Egypt and Levant

'We mapped a lost branch of the Nile River – which may be the key to a longstanding mystery of the pyramids' (The Conversation, 17 May 2024)

'Australia leads progress in agriculture project in Asia and the Pacific' (11 December 2024)

'Paradox lost: wetlands can form in deserts, but we need to find and protect them' (The Conversation, 3 February 2021)

'Australia’s rivers will be unrecognisable by 2070' (Australian Geographic, 22 April 2020)

'Australia’s inland rivers are the pulse of the outback. By 2070, they’ll be unrecognisable' (The Conversation, 21 April 2020)

'Enhancing crop productivity in Asia-Pacific countries by improving soil and water' (6 February 2018)

'Preventing soil erosion with nuclear know-how' (21 June 2017)

'Embracing change: Dr Tim Ralph on conservation' (19 September 2016)

Master of Research at Macquarie University | Pursue your passion (YouTube, 6 September 2017)

Professional Experience with Macquarie University’s PACE program: environmental industry partners (YouTube, 7 July 2015)