LiDAR will improve open space, resource management
A new laser-imaging technique known as LiDAR (Light Detection and Ranging) has allowed a consortium of Sonoma County agencies, including the Open Space District, Water Agency and more, access to detailed vegetation and topographical maps that will improve decisions made in the purchase of conservation easements and water resource management.
The new LiDAR technology allows for much finer-detail imaging and mapping of terrain, vegetation and buildings than just aerial-view photography or sonar, according to Sonoma County Open Space District Conservation Planner Tom Robinson. “LiDAR gives an incredible detail of what’s on the ground, in addition to the ground itself,” he said. “LiDAR gives you a 3-D representation of vegetation...and right off the bat that’s very important for the Open Space District.”
Robinson went on to list all the data LiDAR can provide, including the determination of pervious and impervious surfaces that affect where water is able to drain through the ground and replenish the water table, as well as vegetation data that will help determine the Open Space District’s conservation easement purchases and knowledge of high fire-risk areas.
LiDAR is also able to map terrain down to 1-foot contours, a level of detail that “people are still pinching themselves over,” Robinson said. “That’s an incredibly fine-scale data set, useful for site design, building plans, everything from the Water Agency’s pipelines to vineyard management to parks management...anytime you want to modify the land, you need high quality data. Good data will help us all achieve better decisions.”
Sonoma County Water Agency Chief Engineer Jay Jasperse also has plans to use the new LiDAR data for drought mitigation and water resource management. “There’s multiple benefits,” he said of the new imaging system. “One example is at Lake Mendocino, one of the two reservoirs we operate, the water level was so low we were able to fly over it and get the topography of the bottom of the reservoir. That helps us with storage calculations.”
Jasperse went on to describe the uses of LiDAR data for flood control, as it would provide better elevation data along channels and streams, and how the detailed vegetation data would help determine what areas need more attention from the department’s small-stream maintenance program. The information also allows for a more accurate assessment of wildfire risk, “which impacts water supply and flood control,” he said.
“We’re basically using it to enhance a lot of the things we’re already doing, or planning to do, like flood control modeling or street maintenance programs,” said Jasperse. “It’s providing us better information so we can do it more effectively, and cost-effectively.”
According to Robinson, the new data was made available through a collaboration of local and federal agencies, including NASA, the Sonoma County Water Agency and the county GIS (Geographical Information System), just to name a few.
More information and data, which has been made available to the public, may be collected at www.sonomavegmap.org.