The Pilbara region in Western Australia is an area with many open-pit mines and the location of frequent river diversion. There is a poor understanding of the regional watercourses and limited guidelines for the incorporation of geomorphic and environmental elements into river diversion designs. We developed a series of hydrogeomorphic guidelines for headwater channels in the Eastern Pilbara, Western Australia.
We undertook a large-scale regional geomorphic analysis of headwater rivers, before focusing on the variability in river reach form. Using SfM, the presence and distribution of channel features were mapped. The result was a high-resolution “recipe” or classification of features for a river addressing the natural limits, roughness contribution, and character of natural rivers within the Pilbara. Direct rainfall modelling was applied to identify appropriate rainfall flood frequency estimation for these small ungauged catchments.
This knowledge was integrated to produce a series of modelled guideline hydraulic criteria for the various headwater channels. This guideline hydraulic criteria are intended for use in river relocation channel design, in addition to helping us understand more about the complexity and variability of headwater channels within the Eastern Pilbara.
Our results highlight the importance and diversity of headwater channels in the Pilbara. Understanding geomorphic variability and the underpinning processes within these channels can improve the development of quantitative guidelines and enhance the development of closure criteria for artificial river relocation channels carried out within the region.