A new set of topographical maps and data is now available for all 99 Iowa counties. Department of Natural Resources spokesman, Chris Ensminger, says they collected the data by airplane The plane flies the state and constantly sweeps the ground with light pulses, in a system known as “LiDAR”, which stands for “Light Detection And Ranging.”
They measure the return of the light pulses and use GPS to determine their exact location. Ensminger says this has given them a very accurate elevation map they can use for projects such as mapping wetlands. He says it has let them map areas where they didn’t have very good information.
Ensminger says the north-central part of the state, or “Prairie pothole” part of the state where things are very flat and they had trouble telling where the water was flowing. He says another thing they are doing is creating a floodplain map. Ensminger says the mapping is a joint project of the D.N.R., the D.O.T., the state ag department, and the U.S.D.A. Natural Resources Conservation Service. He says maps will be helpful in a lot of areas.
Ensminger says air quality people are looking for the best places to place windmills, and power companies are looking for the changes in elevation and their impact on the sag in power lines, as they don’t want lines that are too tight or too loose. Ensminger says they are allowing anyone to use the information for free.
He says the information is available at the D.N..R.’s G-I-S library which has two-foot contours, shaded relief maps and digital elevation models. The flour-point-three million dollar cost of the project was split among the partners. Ensminger says the D-N-R believes it was well worth the cost and they can recapture 300 to $400,000 yearly by cutting elevation work and making faster decision on projects.
Ensminger says it will replace a large part of the work they’ve had to do on projects and he says over three or four years they should be able to recoup their part of the project. He says in the past you had to spend money for a survey on a project and then wait for it to be completed, and by the time the survey was done, you were pretty well invested in the project. You can access the information with the proper software from the D.N.R.’s G-I-S library at: www.igsb.uiowa.edu/nrgislibx.
The original LiDAR data points for computer-aided design are available via the University of Northern Iowa’s library at: www.geotree.uni.edu. LiDAR is available only to those with G-I-S software. The D.N.R. plans to have the data and updated aerial photography available on its interactive mapping website later this spring. Ensminger says that website will allow you to print accurate elevation maps for planning hunting, hiking, skiing and sledding trips.