A remotely-sensed (satellite) image of the Perth, Western Australia region

Using remote sensing for environmental monitoring and mapping

Remote sensing is an important tool in environmental management, providing up-to-date, detailed information about land condition and use.

• 22 April 2008 | Updated 14 October 2011

What is remote sensing?

• Remote sensing
• How remotely sensed data are used

Remote sensing

Remote sensing is one of a suite of tools available to land managers that provides up-to-date, detailed information about land condition. Remote sensing uses instruments mounted on satellites or in planes to produce images or 'scenes' of the Earth's surface.

Remotely sensed images can be used in many applications, for example:

• mineral exploration
• monitoring ocean currents
• land use planning
• monitoring the condition of forest and agricultural areas.

The uniqueness of satellite remote sensing lies in its ability to show large land areas and to detect features at electromagnetic wavelengths which are not visible to the human eye.

Data from satellite images can show larger areas than aerial survey data and, as a satellite regularly passes over the same plot of land capturing new data each time, changes in the land use and condition can be routinely monitored.

How remotely sensed data are used

The information from remotely sensed images can be used in a number of ways for a number of purposes. It is usually combined with information from other data sources and on-the-ground observations, called `ground truth', to get a more complete picture of what is happening and to check suspected features or changes.

As part of the Land Monitor project, for example, scientists from CSIRO and other agencies such as Agriculture Western Australia and Conservation and Land Management have been using remotely sensed images to monitor changes in land condition.

Studies have focussed on mapping and monitoring changes in productivity caused by:

• monitoring wind erosion
• monitoring waterlogging
• monitoring the condition of remnant vegetation
• cereal crop yield mapping
• predicting salinity
• monitoring rangeland condition.

Remote sensing provides a cost-effective method for mapping and monitoring broad areas. It also has the advantage over land-based monitoring that disease, such as dieback, is not spread between locations by movement of vehicles or people through contaminated areas.

Archived remote sensing data can be used to monitor how areas have changed through time. Monitoring information can then be combined with landform information to help predict which areas are at risk from salinity in the future, allowing remedial action to be taken where it is needed most.

Remote sensing is also increasingly being used for large-scale environmental monitoring programs like the State of the Environment Report and state-wide projects funded by the Natural Heritage Trust. It is able to offer large-scale monitoring relatively cheaply and easily, and can provide a baseline for future monitoring.