Fluvial Geomorphology is the study of rivers and the processes which shape them and the surrounding land. It studies how these dynamic watercourses evolve, migrate, and interact with the environment and create landforms around them.
Rivers are very dynamic and change, evolve, and morph over time. Fluvial geomorphology seeks an explanation for the mechanisms and processes which control these changes. It also helps us to understand mechanisms like channel patterns, sediment transport, aggradation (delta/deposition), and degradation (erosion).
The study of fluvial geomorphology involves a collection of field observation, laboratory testing, empirical design, and computer modeling.
Natural Channel design is an approach to river and stream restoration that aims to mimic the dominant form and mechanisms of the channel which are identified using fluvial geomorphology. It involves the design and restoration of channels to resemble their up and downstream reaches or reference reach conditions.
The main objective is to improve ecological integrity, enhance habitat diversity, and reduce erosion and sedimentation concerns.
Key components of natural channel design include:
- Hydrology and Hydraulic Analysis
- Reference Reach Assessment
- Channel Stability and Streambank Protection Measures
- Channel Morphology (Channel shape and form)
- Riparian Corridor Restoration
- Long-term monitoring and adaptive management
Why Do We Need Fluvial Geomorphology?
A fluvial geomorphic assessment is essential when considering development within a watercourse or in a landform shaped by the geomorphic processes of the watercourse. This assessment will provide valuable insights into the dynamic nature of the watercourse and its surrounding landscape, including the potential risks associated with the proposed development. By examining the channel patterns, sediment transport, erosion and deposition history, and other relevant factors, the assessment can inform land use planning decisions, help identify appropriate mitigation measures, and ensure the sustainable management of the watercourse and its associated landforms.
If the fluvial geomorphic assessment reveals any issues or concerns related to the proposed development’s impact on the watercourse and its surroundings, mitigation measures can be developed using natural channel design principles. By applying these principles, potential adverse impacts can be addressed effectively, and the overall environment can be enhanced. Mitigation measures may include restoring natural channel morphology, implementing bank stabilization techniques, promoting vegetation growth along stream banks, and considering the ecological needs of the watercourse and its associated ecosystems.
What is McIntosh Perry’s experience in Fluvial Geomorphology?
We are currently realigning a watercourse (a tributary to Ganaraska River) as a part of the Highway 401 Choate Road Bridge Replacement. The future expansion warrant for the widening of the roadway which leads to the bridge embankment close to this watercourse and poses a public safety hazard. As a result, we realigned the watercourse away from the harmway using natural channel design principles.
We have in-house engineers who have experience with Fluvial Geomorphology.
Who is the best person to contact about the new services?
As part of the Highway 401 Choate Road Bridge Replacement project, our team is currently engaged in the realignment of a watercourse tributary to the Ganaraska River. This realignment is necessary due to the future expansion plans for the widening of the roadway, which would have placed the bridge embankment too close to the watercourse, posing a potential public safety hazard. To address this concern, we have chosen to realign the watercourse using natural channel design principles.
The drawing above depicts the stream realignment and planting plan for a tributary of the Ganaraska River in Port Hope, ON. It illustrates the proposed meandering realigned watercourse with site-specific planting plan for the riparian corridor (the area between land and river). The proposed stream bends are protected using bio-engineered erosion preventative designs such as:
- Live fascines (bundles of live wood placed in a trench along the edge of the watercourse)
- Rootwads (the lower trunk and root fan of large trees placed strategically to prevent erosion)
The channel in the diagram was designed using natural channel design Principles.
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