This is a gdb file used in open data - The gdb has the Digital River Network (0.2 ha) A GIS-based high-resolution digital river network (DRN) representing stream network within each of the 13 Freshwater Management Units (FMU) across the Northland region. The DRN has been produced by conducting catchment and drainage line analysis on a “hydrologically-enforced” digital elevation model (HE-DEM) at 2ha and 0.2 ha flow accumulation thresholds. The HE-DEM was produced by ‘burning’ of hydraulic blockages on DEM produced from 1m regional LiDAR, which ensured the waterways follow their correct natural path as often as possible. A suite of attributes has been added into the DRN GIS layers to make them useful for a range of analysis and modelling purposes in Northland.DescriptionThis GIS layer is a vector dataset (polylines) representing stream network at 0.2ha flow accumulation threshold (i.e., 0.2ha is the minimum size of a headwater catchment), which comprises individual stream segments with unique IDs. It was produced by splitting a stream definition raster (developed from a 1m flow accumulation raster) at each stream intersection. Each stream segment represents the catchment delineated at 0.2ha flow accumulation threshold, which drains that area.Detailed Methodology report describing the datasethttps://www.nrc.govt.nz/resource-library-summary/research-and-reports/rivers-and-streams/high-resolution-digital-river-network-for-northland/Other DetailsData Provided By: Manas Chakraborty (Resource Scientist- Freshwater, NRC)
