Land Monitor is a coordinated initiative originally set up by the National Dryland Salinity Program (supported by the National Heritage Trust and Western Australian Salinity Action Plan) and aimed to systematically monitor salt-affected land and remnant vegetation change over the agricultural area of south west of Western Australia. Over time, various iterations of Land Monitor described below have expanded the range of products available and their geographic extent. Partner agencies include:
The original objectives of Land Monitor under the National Dryland Salinity Program. Land Monitor purchased, rectified and calibrated Landsat TM (25 metre spatial resolution) summer imagery and then enhanced images to produce vegetation monitoring products to:
In 2001, the agencies agreed to continue to acquire and process satellite imagery for Land Monitor II with the aim of providing annual mapping of remnant perennial woody vegetation in the agricultural area of south west western Australia, and provide an updated picture of salinity. Products included:
The Land Monitor program continued to progress with 2018 seeing the first delivery of vegetation products across the whole state of Western Australia rather than just in the South West (increasing the area monitored from 18 million ha to over 252 million ha per annum). Land Monitor III may also progress towards creating some new products. Please see the products page for more information as LM III is fully implemented.
The data produced by Land Monitor 1 are still widely used. The outputs included a 10m digital elevation model across the south west agricultural zone, identification of saline affected areas and areas at risk of becoming saline. The following flowchart shows the structure of the project. More information about each component of the project can be found by scrolling down this page.
Collaborative research work under the National Dryland Salinity Program has developed a range of tools that can be used to map areas of land affected by salinity and monitor changes in the area of salinised land. This work is based on highly sophisticated use of Landsat TM data, digital elevation models and surface water accumulation models coupled with extensive ground truthing.
Landsat scenes are available every 16 days from 1987 onwards and can be gathered from archived collections. Each scene covers approximately 186 km x 186 km. Digital elevation models (DEMs) can be produced from contour data provided by the Landgate.
The research work has shown that spring Landsat images are essential for mapping saline land. Ideally, images from three years should be used, to enable an accuracy of greater than 90%, if digital elevation data are also available. Once the saline areas have been identified, the change in area over time can be determined by comparing sequences of images. This provides the only operational method for accurate detection of past trends in the area of salinised land over large areas.
A subset of the Land Monitor salinity product. Cream represents agricultural land.
By combining Landsat scenes, digital elevation models (DEMs) and surface water accumulation models, areas at risk from future salinisation can be predicted. Accurate, high resolution contour data are required to produce accurate predictions of salinity risk.
A subset of the Land Monitor Valley Hazard product overlaid on a Landsat greyscale image. Green represent perennial woody vegetation, orange and red represent salinity, light blue represents mapped water bodies whilst dark blue to yellow represents height above flow path (0-2m) as indicated in the legend.
Landsat scenes purchased for the Land Monitor project from 1987 onwards are held in an archived collection. Each scene covers an area of approximately 186km x 186 km. Accurate, high resolution contour data are available for only a small proportion of the south-west. Land Monitor has produced high quality DEMs using automated techniques. Subsets of the Land Monitor DEM may be purchased for environmental management purposes.
Land Monitor DEM
Establishing a baseline for continued monitoring
The Land Monitor project has:
Remnant vegetation can be monitored using summer dry season Landsat imagery. Mapping and detecting trends in the extent and condition of both natural and revegetated areas have been field tested and proved accurate, within reasonable limits, by a pilot study in the Kent Catchment. Land Monitor has mapped changes in the extent and condition of remnant vegetation and revegetation since 1988.
A subset of the Land Monitor Perennial Vegetation Change 1990 to 2017 product. Red is loss in 1990-2017, blue is gain in 1990-2017, green is present both in 1990 and 2017