Long Oral Presentation 12th Australian Streams Management Conference 2026

Three models walk into a pool: A process-based, multi-method framework for understanding dryland pool sediment dynamics   (138639)

Sam Munger 1 , Ben Pearson 1 , Jack Clothier 1
  1. Hydrobiology, QLD

Pool habitats in dryland river systems are highly sensitive to changes in flow and sediment regimes, yet predicting their response to catchment disturbance remains a persistent challenge for impact assessment and management and requires approaches that move beyond single-metric or event-scale assessments. This study applied a multi-method, process-based framework to evaluate sediment dynamics within pools subject to catchment contraction associated with mine expansion in Western Australia.

The approach integrated three components:

  1. Stochastic long-term sediment yield modelling using a Monte Carlo framework to characterise probabilistic sediment delivery.
  2. Event-based sediment delivery modelling to resolve drivers of sediment flux across a range of flow magnitudes.
  3. Event-scale flushing assessment, linking hydraulic modelling outputs with sediment mobility thresholds to quantify scour and transport across grain sizes.

These components were synthesised through a conceptual sediment balance model, resolving the interaction between delivery, transport, and in-pool storage.

This integration of temporal scales and processes provided a level of diagnostic capability not typically achieved through conventional assessments, enabling cumulative trends and event-driven behaviours to be interrogated within a single framework. The approach supported a defensible, semi-quantitative evaluation of impact likelihood and severity grounded in physical process representation.

By resolving how sediment systems reorganise under altered boundary conditions, this methodology provided a robust basis for anticipating and managing processes in changing dryland river systems.