Borstad Associates Ltd. - Change Visualization

Today, the Earth and its natural resources are often viewed in the context of ownership, management and sustainability. Maps are an important part of planning, negotiation and project implementation. However, simple lines on a page do not always adequately capture the life of a watershed or landscape. Borstad Associates Ltd. offers satellite image-maps that describe the present state of the landscape, its past, changes over time, and even its future.

What is satellite imaging?

There are now hundreds of satellites orbiting the globe, continuously viewing the earth in many different ways. The data they collect is used to describe, visualize and map the earth - from the very small to the very large, on land, the ocean and in the atmosphere. Satellite imagery is becoming more and more common - on the weather channel, on the news, and on the Internet. In each case, remote sensing professionals are working behind the scenes to convert the data to information and produce knowledge products that help us plan our lives and manage the land.

Satellite imaging is used for:

Visualization: illustrating the past, present and future appearance of the land for use in, for example, the public planning process,
Coastal management: describing the changing ocean productivity and the effect of man's activities on coastal water quality; short and long term fisheries predictions; aquaculture siting,
Environmental compliance and assessment: monitoring water quality and industrial discharges; reforestation and land reclamation after resource extraction,
Environmental disaster assessment: mapping the effects of forest fires, disease and infestation, earthquakes, storms and flooding,
Environmental monitoring: describing climate change and tracking short and long term weather patterns and their impacts,
Exploration: for mineral and other resources,
Land and resource planning: planning and managing timber harvesting, oil and gas exploration, transmission corridors, urban development and agricultural expansion; mapping wildlife habitat and fragmentation.

What can Borstad Associates and satellite imaging do for me?

At Borstad Associates we understand the importance of environmental and resource mapping and offer a wide range of products and acquisition techniques customized for your application.

Visualizing the present: With frequent updates, satellite imagery can be used to produce up-to-date maps of land use. For example, the natural colour image below illustrates the effect of timber harvesting and oil and gas exploration on the landscape south-east of Dawson Creek, BC as of October 2001.

Visualizing the past: For most areas, a large imagery archive allows us to look back 33 years. In the September 1991 image below, the digital data is recombined and depicted in false colour. This type of image accentuates the colour differences in the forest and assists in interpretation. In this mapped near-infrared image we see:

Dark red/ purple - coniferous,
Light red -deciduous,
Cyan - recently cut areas.

Visualizing changes over time: Working with several images of the same area, analysts can quantitatively map changes over time due to activities such as forest succession, timber harvesting, agricultural and urban expansion, resource exploration, and infrastructure development. In the change detection map below, we show the changes between 1991 and 2001. Of the 24, 500 ha in this scene, approx 15780 ha of this area was originally coniferous forest. Only 8437 ha remained as conifers in 2001. Approximately 7343 ha (46% )of the coniferous forest was cut prior to 2001. Most of this (4750 ha) was cut many years prior to 1991 and had regenerated to deciduous by the time of imaging. 894 ha was cut before 1991 and not regenerated by 1991. In total, 5644 ha (36% of original forest) was cut prior to 1991. Between 1991 and 2001, another 1699 ha (11% of original forest) was cut - about half (889ha) in the early part of the decade (it had regenerated to deciduous), while the remainder (810 ha) was still a new bare cut in 2001.

The colours in this classified change detection image above represent:

Green - 8437 ha - remaining coniferous forest in 2001,
Orange and yellow - 4750 ha - coniferous forest cut prior to 1991 that had regenerated to deciduous by 1991,
Magenta - 894 ha - new coniferous forest cut prior to 1991 that had not yet regenerated by 1991,
Cyan - 889 ha - coniferous forest cut between 1991 and 2001 that had regenerated to deciduous by 2001,
Red - 810 ha - new coniferous forest cut prior to 2001, not yet regenerated by 2001,
Dark blue - water.

3D viewing: The examples below illustrate how 3D viewing helps in the interpretation of change detection maps. Below are two images of Skidegate Inlet in Haida Gwaii (Queen Charlotte Islands). On the left is a true colour image captured in 2002. On the right is a change detection image based on satellite data from 1991 and 2002.

The colours in the change detection image (right) represent:

Blue/purple - harvested just prior to 1991,
Red - recent harvests in 2002,
Pink - harvested between 1991 and 2002,
Light green - secondary growth, deciduous forest,
Dark green - old growth coniferous forest.

The change detection image shows that the majority of the Skidegate Valley has been harvested for timber, with the remaining old growth forest lining the mountain ridges and steep and inaccessible slopes. A fly-over movie showing the effect of timber harvesting in Haida Gwaii has been generated for this area and can be viewed by clicking here Haida Gwaii Over View.

Visualizing the future: These same techniques can be used to visualize the effects of future development on a natural area or reclamation of a disturbed area. The example below illustrates a proposed mine tailings dam before and after development.