River Diversity

Written by:
Kirstie Fryirs, Gary Brierley and Simon Mould.

Cover image credit: Google.

Australian rivers are different to those in other parts of the world. Our ancient land mass – subject to droughts and flooding rains, cared for and lived with for tens of thousands of years – has produced globally distinctive landscapes and ecosystems that can’t be found anywhere else.

Within Australia, there is an enormous diversity of rivers. The images below are just a few examples, demonstrating the range of forms and features that make up rivers on this continent. This diversity is what makes each river so special and worth valuing.

Photo credit: Google Earth and Kirstie Fryirs.

Franklin River – confined

The Franklin River in Tasmania is a ‘confined gorge.’ It features waterfalls, rapids and bedrock steps with no floodplains. The river is formed by the sculpting and infrequent movement of boulders. It has little capacity to adjust because it is ‘stuck’ within a bedrock-confined valley setting. Rivers like this are commonly found in the upstream, headwater and gorge country. They are steep and contain sections of white water.

Photo credit: Google Earth and Gary Brierley.

Bellinger and Macleay Rivers – partly confined

The Bellinger (left) and Macleay (right) rivers, North Coast NSW, are ‘partly confined, bedrock margin controlled, discontinuous floodplain’ rivers. They feature gravel point bars, bedrock pools, gravel riffles and have distinct floodplains on the bends. These rivers are formed by the movement and deposition of gravel, sculpting of bedrock and deposition of finer sediments on the floodplain. The floodplains are occasionally stripped of sediment in large floods. These rivers have some capacity to adjust because it is only partially confined by its bedrock valley. Rivers like this are very common in the middle sections of catchments, in rugged or rounded terrain. They are moderately steep and contain areas of white water and more tranquil water.

Photo credit: Google Earth and Kirstie Fryirs.

Cooper Creek – laterally unconfined

Cooper Creek in Queensland is a ‘laterally unconfined, continuous channel, anastomosing’ river. Its features are made of mud (silt and clay), and include mud pools, runs and mud bars. This river sculpts the surrounding mud. Pools are scoured out and sediment is deposited to form runs and bars. The river has limited capacity to adjust because it is ‘stuck’ in the mud – these are often called ‘lazy’ rivers. Rivers like this are found on very wide, very low-slope areas that are common in central Australia. They have areas of tranquil water, when flowing (flow is irregular).

Photo credit: Google Earth and Kirstie Fryirs.

Mulwaree River – laterally unconfined, chain of ponds

The Mulwaree River, southern highlands, NSW is a ‘laterally unconfined, discontinuous, chain of ponds’ river. It features distinctive pools separated by swampy ground with no continuous channel connecting. This river is called an ‘antecedent’ river because the ponds are remnants of an ancient river that once contained large pools. There is some groundwater contribution to the water held within ponds. These rivers are found on wide, low-slope areas, often in plateau country. The ponds contain water year-round and do not typically dry out.

River diversity and geomorphology

One way of understanding and articulating the value of river diversity is to use geomorphology – the study of earth surface forms and processes. Geomorphologically-informed understandings can work with other river knowledges to help us understand why our rivers are diverse and how we can best care for the things that make our rivers different and valuable.

A geomorphologically-informed understanding of river diversity goes beyond describing difference. It also sets out to explain difference in terms of the processes that drive rivers as dynamic, living systems, and the catchment-scale relationships that produce particular rivers in particular places. It is an observational and interpretative science, grounded in the reality of how rivers are now and how they might be in the future.

To help us understand and articulate the things that we value in a river system, we need a coherent information base – one that relates multiple ways of seeing and knowing rivers with scientifically-informed insights.

The River Styles Framework

The River Styles Framework provides an approach for the geomorphic analysis of river systems. The Framework blends field-based insights with data generated using emerging technologies such as satellite imagery to interpret a river’s character, processes and behaviour (functionality), its condition (integrity), the potential for the river to recover (improve in condition) and to translate this information into a strategic, multi-scalar agenda for river management (e.g. from landform to reach to catchment to region).

The four stages of the River Styles Framework build upon each other (they scaffold), providing a consistent set of data for understanding rivers from a geomorphological perspective. The River Styles Framework can be applied to any river system and is open-ended. It does not try to force rivers to fit into pre-existing categories or classes. Instead, it seeks to understand rivers on their own terms.

Stages of the River Styles Framework

The River Styles Framework is a learning tool for generating a coherent information base to inform river management. Such information is required for developing conservation and rehabilitation plans that work with the river and respect the inherent diversity of rivers in the landscape.

At the reach scale, we can…
  • Rapidly integrate geomorphology into property management plans to make smart decisions about any rehabilitation measures that might be needed
  • Identify habitat types based on geomorphic character, to help protect valuable species
At the sub-catchment and catchment scales, we can…
  • Identify and assess threatening processes (before they become a problem)
  • Create a vision for what is realistically achievable in a catchment action plan
  • Justify and verify where low- or high-cost interventions are most likely to be (in)effective
At the state/territory scale, we can…
  • Coordinate whole-of-government programs using a consistent information base
  • Transfer understanding from one place to another (and also know when it’s not appropriate to do so)
  • Prioritise managment activities to minimise waste and achieve the best environmental outcome and return on investment

To date, the River Styles Framework has been used on six continents for a range of purposes and in some very different landscapes. Some particularly interesting uses include:

  • Using information on river character and behaviour to map and predict habitat distributions for threatened fish species (Columbia Habitat and Monitoring Program (CHaMP), USA; NSW Department of Primary Industries – Fisheries)
  • Using river condition data to support State of the Environment Reporting via the NSW Government’s River Condition Index (NSW Department of Planning, Industry and Environment – Water)
  • Using river character and behaviour, condition, recovery potential and prioritisation information to plan river management at the catchment scale (NSW Catchment Management Authorities; VIC Catchment Management Authorities).

Learn more…

If you would like to learn more about applications of the River Styles Framework to support river management, we offer professional short courses. The next course will be held in Goulburn, NSW in May 2020. Registrations are now open. For more information on the River Styles Framework or the professional short course, please visit

About the authors:

Professor Kirstie Fryirs

Fluvial geomorphologist and co-developer of the River Styles Framework, Macquarie University


Professor Gary Brierley

Chair of Physical Geography and co-developer of the River Styles Framework, University of Auckland

Dr Simon Mould

River Styles Co-ordinator, Macquarie University