Eye in the sky facilitates resource management. (Technology).

A cluster of technologies, including remote sensing, image analysis and Geographic Information Systems (GIS), are being harnessed to create a digital land use/land cover classification system and a complete set of up-to-date maps of Saskatchewan's forested land base. Once completed, the resulting database will be an invaluable tool for industry and government in the management of the province's natural resources.

While a set of topographic maps exists for the entire province, Saskatchewan lacks a complementary, thematic land cover/land use map of its sparsely populated North. Satellite remote sensing can be used to create maps at a reasonable cost; although these maps are not as detailed as those derived from photographs, they provide sufficient information to create an inventory of land cover, land use and vegetation.

A single Landsat satellite image covers over 30,000 square kilometres, and can be classified using image analysis software to determine the vegetation on a piece of land as small as 900 square metres. Using this process, it is possible to tell, for example, whether land is in summerfallow or crops, whether trees are hardwood or softwood, or whether land is suitable for wildlife habitat or commercial uses.

Land cover maps have already been completed for southern Saskatchewan. The South Digital Land Cover database was created between 1995-1998. An extension of the Western Grain Transportation Payment Program, it was used to identify and calculate cultivated cropland to help determine the Crow pay out for Saskatchewan farmers, resulting in considerable cost and time savings for the province.

Now, the North Digital Land Cover (NDLC) project is in the works to create a similar database for the North. It will provide a circa 2000 "snapshot" of the forested region of Saskatchewan, from the boreal transition ecoregion to the North West Territories border. The cost will be $1 million, which is much less than the conservative estimate of $20 million for a traditional forest inventory based on aerial photographs.

The NDLC was prompted by a need in the private, public and academic sectors to obtain more information about Saskatchewan's land base in order to make intelligent land use decisions. It will allow researchers and managers to obtain information, for example, about tree species, land cover and land use that will be useful in making forestry decisions by helping foresters zero in on areas that are likely to be productive.

The maps will also assist governments and industry with disaster management planning. It will be possible to use NDLC images to assess landforms, fuel types and potential transportation routes through the forest or to assist fire managers to direct their forces to protect valuable assets at risk.

Another important use will be in environmental monitoring and modeling. The information will serve as baseline data, helping researchers in climate change studies to identify environmental shifts such as wetland expansion and contraction, fire frequency and pattern analysis and dynamic vegetation adaptation.

One area where it is expected the NDLC would be of particular value is in the boreal transition ecoregion on the edge of the boreal forest. There is considerable interest today in the potential for agroforestry, or tree plantations, as an alternative to conventional agriculture in the transitional zone. The NDLC will help landowners, planners and forest companies in deciding which lands might be profitably converted to fast growing hybrid poplars for pulp production.

Tied into this is the issue of carbon sequestration, an important element of the Kyoto Accord on climate change. This project will make a significant contribution to Saskatchewan's and Canada's ability to monitor the amount of carbon being stored by its natural forests, forest plantations or farmlands.

Work is currently underway on a preliminary carbon credit trading system which may be useful in obtaining and/or selling carbon credits, helping Canada to meet its Kyoto targets and potentially to increase economic activity. Although a carbon credit system has not been agreed on, it is likely that some method of tracking carbon storage in natural and agricultural systems will be a key element of Kyoto, and Saskatchewan's NDLC database will help make this possible.

Helton Fan is a Research Scientist with Remote Sensing and Spatial Information at the Saskatchewan Research Council.