Turning back time for rivers: restoring river and wetland hydromorphic connectivity using a Stage 0 approach.

´Stage 0´ is the pre human disturbance state of rivers and a key goal of river restoration.

Recent evidence demonstrates that for many rivers, Stage 0 is a multi-thread (anastomosing) planform with riparian wetlands. Restoring to Stage 0 will maximise ecosystem services, including providing key rearing grounds for salmonid fish.

However, application of Stage 0 restoration is limited because; (1) the interaction between geomorphic and biological processes in natural anastomosing rivers is poorly understood, and (2) Stage 0 employs novel techniques (e.g. channel re-grading & wood) which may increase risk to riparian land use and infrastructure.I aim to understand the interaction between geomorphic, hydrological and biological processes in a pre-disturbance river and quantify the influence of restoration design on the morphological response of rivers to Stage 0 restoration.

I will achieve this via 3 projects.

First, I will study the association between channel morphology and sediment transport, flow velocity and invertebrate community processes in a natural anastomosing channel.

Second, I will consider how restoration design affects how channel morphology develops after Stage 0 restoration, using a meta-analysis of completed projects.

Third, I will use hydraulic flume experiments to simulate how restoration design influences river geomorphic and hydrological processes and the response of restored rivers to flood events. The results will guide restoration of alluvial rivers.