Mapping the future

Comparison of images
A comparison shows the higher definition of a digital elevation map next to an image created from a traditional contour map.
MPR Photo/Dan Gunderson

Chuck Fritz is a little like a kid at Christmas. He's spent the past several years organizing a digital mapping project, and the first results will soon be ready.

"This is pretty cool. The technology is truly amazing. I can't wait to see the first data sets," says Fritz as he explains the high tech mapping.

Here's how it works. An airplane shoots rapid pulses from a laser as it flies across the landscape. The laser bounces off trees, houses and the ground, essentially creating a sort of animated three dimensional picture of the earth's surface. It can be combined with satellite photos to create a virtual tour of the landscape and it's all accurate to within inches.

Chuck Fritz has spent years managing water projects. That's why he's so excited about a better map of the earth's surface. There are hundreds of projects large and small that affect how water flows across the landscape. The new digital map will make planning those projects faster and more accurate.

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"Before the project is built we can better define what the effects will be. Will it be effective? Will it impact others? Where will it impact others?" Fritz said. "Basically it will increase efficiency at all levels of government. And that's what I'm most interested in."

Chuck Fritz
Chuck Fritz is director of the Fargo-based International Water Institute.
MPR Photo/Dan Gunderson

Manitoba created a digital map several years ago, and homeowners have used it to fight recent floods, he said.

"If I was a landowner south of Winnipeg, I can actually go on line and I can very quickly and easily identify if the structure on my land is threatened," Fritz said. "And I can do a quick online tool that will tell me how many sandbags I need to order."

Water management might be the most obvious reason for a highly accurate map of the earth, but in the future digital maps could affect everything from how much fertilizer a farmer uses to planning highway projects to how you choose a campsite at a state park.

It's all about accuracy. It's the difference between a blurry photo and a clear one. Right now, across much of Minnesota, if you want to know the elevation of a piece of land you pull out a contour map, those maps with the curved lines that show hills and valleys.

But those maps are old and it as it turns out, very inaccurate.

"The elevation data we have in the state, largely because it has always been so expensive to collect, is woefully inadequate, and maps that show elevation are almost cartoons relative to what they really need to be," said Minnesota Department of Administration Director of Geographic and Demographic Analysis David Arbeit. Arbeit said it's not uncommon for the existing maps to be off by as much as 20 feet. That could be disastrous if you use the map to see if floodwater will reach your house, but for state and local government, it means extra expense. For every proposed road or new development, surveyors must be sent into the field to gather data. With digital mapping, planners could simply look at a three dimensional map on a computer.

Lidar stands for Light Detection and Ranging. Laser beams are used to paint a three- dimensional map of the earth's surface.
Courtesy Source: Gary Elwell HKM Engineering, Inc. & Becky Morton Horizons, Inc

Minnesota DNR Geographic Information Systems Manager Tim Loesch said digital mapping would save money on projects like designing trails, mapping wetlands, or predicting environmental damage from development. He estimates collecting digital mapping data would save $3,000 per square mile compared to using traditional survey methods.

Loesch said the data can be used in a variety of computer modeling programs.

"Things like simulating -- here's a drop of water that lands on the landscape. Where is that water going to go? Is it going to flow down the hill, through the feedlot into the trout stream? Or is it going to flow into this grassy area where it's not affecting the trout stream or drinking water sources," Loesch said.

Digital elevation mapping can also help in fighting forest fires because the three dimensional image shows the height and density of trees, and Loesch said the DNR is also thinking about using the data to create virtual tours of state parks.

But that can't happen until the entire state is mapped. Right now there are only a couple of projects funded for flood control, one currently happening in the Red River Valley and one scheduled to start this fall in southeastern Minnesota. A few metro counties also have digital maps, but most of the state is not digitally mapped.

The legislature did not fund a 12 million dollar request to pay for digital mapping statewide. Arbeit said the project would quickly pay for itself in savings to state agencies. He says a recent report from the Legislative Citizen Commission on Minnesota Resources has a number of environmental initiatives that could not be accomplished without digital mapping.

Minnesota progress
Minnesota is slowly gathering digital elevation data. Some state officials say making digital mapping a priority would benefit the environment and save money.
Courtesy State of Minnesota

"You can't address some of the environmental issues they are calling out in that report without elevation data," Arbeit said. "Despite the fiscal challenge state government is facing, I think we're going to save money if we can address this early rather than late."

As legislators begin to recognize the savings and efficiencies that could result from a digital map, Arbeit anticipates growing support for a three dimensional map of the entire state.