Tim’s research focuses on the geomorphology of rivers and wetlands, particularly those in dry landscapes. He has worked extensively in the Murray-Darling Basin, 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 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 a senior environmental scientist with the NSW government (now DPE) 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 DPE and the NSW National Parks and Wildlife Service.

• River channel, floodplain and wetland morphodynamics
• Sediment and agro-contaminant tracing in catchments
• Hydrogeomorphic controls on aquatic ecosystem metabolism
• Wetland responses to inundation, and water and habitat requirements of freshwater biota
• Fire history and impacts on rivers and wetlands
• Anthropogenic impacts on environmental systems, 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
• ENVS3439 Geomorphic Analysis of Rivers and Wetlands for Conservation and Management
• ENVS8403 Science in Environmental Management

Tim has extensive experience as supervisor and mentor to higher degree research students, and is available to discuss options for research projects and degrees.

Current PhD candidates:

• Bradley Graves (PhD project: Channel discontinuity and floodout formation in dryland rivers)
• Megan Gomes (PhD project, co-supervised with Prof. Marc Humphries, cotutelle University of the Witwatersrand, South Africa: The geomorphology and avulsion history of the Mara River and floodplain wetlands in the semiarid Northern Province, Tanzania)
• Amir Arash (co-supervised with Prof. Kirstie Fryirs, PhD project: Flood hydrology and river recovery in Eastern Australia)
• Carl Helander (PhD project: Landscape destabilisation, sediment dynamics and fluvial responses to fire)
• Nicholas Crameri (co-supervised with A/Prof. Emilie Ens, PhD project: Geo-ecological evolution of Indigenous Arnhem Land floodplains: past, present and future)

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)

'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)

'Keeping watch over a wandering wetland' (11 August 2016)