Braided Rivers Seminar 2024: Developing a braided river monitoring programme

Presented by Helen Greenep (ECan) and Justyna Giejsztowt (Wildland Consultants).

Environment Canterbury are contemplating implementing a regional terrestrial biodiversity monitoring programme. One focus is on naturally uncommon ecosystems. With braided rivers being a key Naturally Uncommon Ecosystem in Canterbury, we decided to develop a monitoring programme that includes extent and condition of the terrestrial component of braided rivers. The first step was to determine extent. NIWA had been working on developing a methodology to determine the ‘braidplain’, and we are using the topographic braidplain – determined primarily using LiDAR – as the best representation of braided river extent.

With help from Susan Wiser (Manaaki Whenua Landcare Research) and Justyna Giejsztowt (Wildland Consultants) we came up with a methodology to monitor condition. This involved choosing 200m long ‘reaches’ ranging from the coast to as far up the river as possible. Within each reach vegetation structure/habitats were mapped using the most recent aerial imagery, and then vegetation plots were placed within each habitat type.

So far two rivers (Ashburton/Hakatere and Rakitata) have been surveyed as we develop and refine the methodology.