GeoBase in Action

Satellite Imagery Allows Government Agencies to Monitor Environmental Change

By using imagery acquired by the Landsat-7 remote sensing satellite, Canadian government organizations have improved their understanding of and ability to plan for environmental change.

Imagery acquired between 1999 and 2004 was used to produce a set of orthoimages (geographically accurate images) providing coverage of the entire Canadian landmass — a first for Canada. These have proven to be a rich source of geospatial information for a number of organizations.

Earth Observation for Sustainable Development of Forests

A joint initiative of the Canadian Forest Service and the Canadian Space Agency, the Earth Observation for Sustainable Development of Forests (EOSD) project is aimed at measuring and monitoring Canada's national forests. As part of the EOSD project, the Canadian Forest Service used the Landsat-7 orthoimages to map and classify all of Canada's forests, a job completed in 2006. The Canadian Forest Service achieved this milestone by partnering with provinces, territories, universities, and forestry companies.

Figure 1: Geobase Land Cover layer classified from Landsat 7 image.

EOSD is also used by the provinces and territories to monitor and manage resources for the National Forest Inventory and for carbon accounting done through the National Forest Carbon Monitoring and Reporting System (NFC-MARS). The Canadian Forest Service also employs NFC-MARS for United Nations Framework Convention on Climate Change reporting.

In fact, anyone with internet access can use EOSD information, whether it be an ecologist interested in wetlands, a firefighter studying timber coverage, or a biologist monitoring the pine beetle.

The GeoBase Land Cover Data Layer

The completion of the EOSD project demonstrated successful intra- and inter-governmental collaboration. The precedent EOSD set facilitated projects like the creation of the GeoBase Land Cover. This GeoBase data layer incorporates forest cover data produced by the EOSD project, agricultural data from the National Land and Water Information Service of Agriculture and Agri-Food Canada, and northern non-forested areas data contributed by the Canadian Centre for Remote Sensing.

By combining these information sets, the GeoBase Land Cover data layer will help users learn how human and natural activities are re-shaping the Canadian landscape. This knowledge will assist governments, policy makers, industries, and citizens to better manage our environment and natural resources.

Orthorectified Landsat-7 coverage makes it possible

Natural Resources Canada (NRCan) was instrumental in acquiring the imagery used in the EOSD and Land Cover projects. The Centre for Topographic Information in Sherbrooke, QC, (CTI-S), a division within NRCan, is responsible for the collection, management, and dissemination of topographic information. CTI-S first became interested in using Landsat-7 data to aid in updating Canada's National Topographic Database. A 1999 change to the U.S. government's distribution and copyright policy helped turn this interest into reality.

Figure 2: Subset of a Landsat 7 image

This change in U.S. policy allowed unfettered sharing of the image data, a change that NRCan capitalized on quickly by establishing a collaborative project between 11 federal department and all the provinces and territories to acquire more than 700 Landsat images of the Canadian landmass.

Sharing a Rich Resource

However, the Landsat imagery couldn't be used or shared without first being geometrically corrected (or orthorectified). This process creates images that accurately represent Canada's landmass. Once orthorectification was completed, the images were sent to partners and made available on the GeoBase portal — without charge, or restrictions. Subsequently, all partners were able to use the images to address a wide range of information needs such as for the project (EOSD).