Water

Sub-Theme

Flow Direction Grid

Theme 
Water
Aggregator 
Geoscience Australia

The Flow Direction Grid is a regular grid of surface flow directions accompanying the GEODATA 9 Second Digital Elevation Model (DEM) Version 3. It ascribes to each DEM point one of eight cardinal directions (E, SE, S, SW, W, NW, N, NE) denoting the direction of surface flow from each grid point to one of its eight immediate neighbours.

National Datasets in this Sub-Theme

National Flow Direction Grid

Purpose

The Flow Direction Grid is a representation of the (major) surface water features of Australia excluding external Territories. The dataset can be used for applications requiring accurate representation of absolute elevation values. The elevation of source data high points (hills or mountains) is well represented in Version 3. The 1:250 000m source scale of the elevation grid makes the product useful for national, State-wide and regional applications. It is intended to be used as the basis for production of consistent surface stream network analysis.

Dataset Uses

The dataset can be used for applications requiring accurate representation of absolute elevation values. The elevation of source data high points (hills or mountains) is well represented in Version 3. The 1:250 000m source scale of the elevation grid makes the product useful for national, state-wide and regional applications.

Standards and Specifications

Open Geospatial Consortium (OGC) Web Feature Service (WFS) Implementation Specification 1.1.0 (OGC Document No. 04-094)
Open Geospatial Consortium (OGC) Web Map Service (WMS) Implementation Specification 1.3.0 (OGC Document No. 06-042)

Access and Licensing

Creative Commons Attribution 4.0

Quality

The Flow Direction Grid database provides a 1:250 000m seamless network stream layer for Australia. The Network streams represents the flow direction of streams over the surface of the terrain, based on the GEODATA 9 grid of ground level elevation points covering the whole of Australia with a grid spacing of 9 seconds in longitude and latitude (approximately 250 metres) in the GDA94 coordinate system.

Currency: 2008

Coordinates: Geographical

Datum: Horizontal: GDA94; Vertical: AHD71

Current Status

Maintained by Geoscience Australia with development from the Australian National University (Fenner School).

GEODATA 9 second DEM and D8: Digital Elevation Model Version 3 and Flow Direction Grid 2008 released by Geoscience Australia

Future Status

Short term objective:

  • To improve national dataset with updates from the 1 Second DEM on a catchment boundary

Long term objectives include:

  • Continued spatial upgrades of stream network using latest acquired and higher resolution imagery
  • Improve the national coverage to 1 Second DEM replacing 9 Second DEM elevation models
  • Hydrological enforcement using improved elevation models
  • Develop Open Geospatial Consortium (OGC) (WFS) and (WMS) services

Key Users

Key users of the flow direction grid are Commonwealth, State, Territory and Local governments and the Research and Industry sectors.

Details