Semi-automating the calculation of catchment scale geomorphic controls on river diversity using publically available datasets

A GIS workflow for the identification of corridors of geomorphic river recovery across landscapes

“…With an average reach length of 0.7 km this resulted in adjoining streamline elevation raster values being 0.7 km apart, maximising the likelihood of a downstream decrease in elevation being detected between adjacent reaches using the 30 m resolution DEM. The DEM’s elevation data was then visually examined and compared to the NSW River Styles network of streams to check that the upstream-downstream sequences of reaches was correct [ 14 ].…”

“…There is a growing number of semi-automated workflows for the geomorphic analysis of river systems [14][15][16][17][18][19]. These can provide workflows based on proprietary GIS software toolkits (ArcGIS and TopoToolbox) and python script, which are ideally suited to expert GIS users.…”

Modelling sediment (dis)connectivity across a river network to understand locational‐transmission‐filter sensitivity for identifying hotspots of potential geomorphic adjustment

“…The 1 in 10 year return interval flow has been observed to produce geomorphically effective floods in similar coastal river settings (Lisenby & Fryirs, 2016). Network scale metrics of contributing catchment area calculated from a flow accumulation raster was used to calculate continuous discharge in the Richmond catchment using a discharge–area empirical relationship (Khan et al, 2021b, 2021a). Surveys and samples of bed material size from 25 locations across the catchment were collected in the field during low flow conditions in August 2019 (Figure 1).…”

“…A discharge–area relationship for the Richmond catchment was extrapolated from the historical flow dataset using Log‐Pearson Type III statistical analysis (Khan et al, 2021b, 2021a). For this, long‐term discharge data was obtained for seven gauging stations across Richmond catchment (Supporting Information Figure S1, Table S1 and S2).…”

“…We use the concept of ECA and buffers (Fryirs et al, 2007a), along with graph theory and empirical sediment transport model CASCADE (Catchment Sediment Connectivity And Delivery) (Schmitt et al, 2016;Tangi et al, 2019) to determine the usefulness of this approach for undertaking such sediment (dis)connectivity analyses. A discharge-area relationship for the Richmond catchment was extrapolated from the historical flow dataset using Log-Pearson Type III statistical analysis (Khan et al, 2021b(Khan et al, , 2021a. For this, long-term discharge data was obtained for seven gauging stations across Richmond catchment (Supporting Information Figure S1, Table S1 and S2).…”