Riparian vegetation density estimates based on tree canopy mapping for dSedNet model input for the Western Port catchment, Victoria, Australia

Brief description

Spatial input data to parameterise the stream bank erosion module of the dSedNet model to simulate sediment generation and transport in the Western Port catchment for a 2018-19 study commissioned by Melbourne Water.

Lineage

Melbourne Water provided tree canopy polygon data for riparian zones (0-200m stream buffer) in Western Port. These data represented presence/absence of tree canopy and did not capture vegetation with low vertical projection e.g. grass, shrub. Tree canopy was mapped at a fine scale (e.g. 1: 5000) from remote sensing and aerial image digitisation and captured considerable detail. The proportional area of tree canopy occurring within 1 ha grid cells was calculated across Westernport and resampled to a 20m grid for input to the model. While tree cover alone is not necessarily representative of riparian vegetation that stabilises stream banks that also includes low standing types, it was the only suitable data available to the project at the time as remote sensing products were either too coarse or contained insufficient spatial coverage. The workflow for generating riparian vegetation density estimates from Melbourne Water's riparian tree canopy data was executed within the ArcGIS (version 10.2) environment.