TR.WillametteLuckiamuteSantiam.jpg

Detail of the Willamette River from a lidar data image, showing the Luckiamute River (left) and the Santiam River (right) joining it.

(Oregon Department of Geology and Mineral Industries)

The twists and turns of the historical channels carved by the Willamette River on a relatively flat landscape show up suitable for framing in a poster released by the Oregon Department of Geology and Mineral Industries.

Primarily in shades of blue and white, the poster was created with lidar data.

that uses light aircraft to make amazingly detailed and accurate maps of the earth.

Similar technique was used by the department in the past to make maps of

in 2011 and in 2012 the

both in the Oregon Cascades.

The department has been collecting lidar data in Oregon since 2006. The goal is to cover the entire state, as funding becomes available.

The Willamette River, from Albany (lower) to Independence (upper).

The segment of the Willamette River shown in the new poster flows past Albany (near the bottom of the larger image), north to Independence at the top.

Prominently in the center, the map shows the Luckiamute River joining the Willamette from the west and the Santiam joining from the east.

The swirls outside today's relatively narrow channel show how the river flowed historically, carving different meanders over the eons.

This imagery was featured in the North American Cartographic Information Society’s first Atlas of Design. The image was also highlighted in an

that discussed the interplay of art and technology in map-making today.

The image is available

Nature of the Northwest Information Center, 800 N.E. Oregon St., #28, Suite 965; 971-673-2331;

.

AN UPDATE:

Lidar data is collected by low-, slow-flying aircraft with equipment that shoots millions of laser points to the ground. When the data is studied, an amazingly accurate model of the ground can be mapped.

It is possible to strip buildings and vegetation from the images, so that only the ground is shown. In the Willamette River poster, the shades of white and blue show elevations. The purest white color is the baseline, (the zero point, at the lowest point near Independence on the upper part of the image). The darkest blue is 50 feet (or higher) than the baseline.

The shades of white show changes in elevation, between 0 to 50 feet. This brings out the changes made by the river channel in the last 12,000 to 15,000 years, in the time since the landscape was basically swept clean by the Missoula floods.

The result is an eye-catching image.

"The different movements of the river make the image take a liquid shape, even almost like a cloud of smoke,'' said Dan Coe, a cartographer who made the map for the Department of Geology. "This shows the magic of lidar.''

-- Terry Richard