Channel Mapping and Physical Habitat Monitoring With a Green Lidar (EAARL) USDA Forest Service, Rocky Mtn. Research Station Boise Aquatic Sciences Lab Jim McKean - Forest Service Wayne Wright - NASA Issue: All organizations responsible for river management require basic information describing channel physical structure and habitat. Current stream mapping and monitoring is expensive, labor-intensive and somewhat subjective. Only local sampling of subsets of the full range of conditions in a channel network is possible. Channel inventory, monitoring, and management are significantly limited by this inadequate description of aquatic physical habitat. Current Work: The Forest Service, Boise Aquatic Sciences Lab is using a green LIDAR to map channel bedforms in live streams and vegetation and topography in the surrounding floodplain. The work is in collaboration with the NASA Wallops Flight Center, developers of the Experimental Advanced Airborne Research Lidar (EAARL), and includes: • Testing the accuracy and range of working conditions of this water-penetrating LIDAR • Extracting basic channel morphology with dramatic improvements in precision and power to detect change; making improved hydraulic predictions of bed mobility, sediment transport, and sediment size sorting • Mapping aquatic physical habitat and correlating habitat with known fish use • Monitoring channel changes using multi-year EAARL data • Investigating the nature and causes of the spatial structure of channel bedform topography
Fig. 1 Accuracy of EAARL data relative to a ground survey. The points are positions of lidar reflections and ground survey data respectively.
Fig. 2 Typical channel bedform and nearby floodplain topographic map derived from EAARL data. These results were produced from a few seconds of flight time. This technique provides the first ever opportunity to seamlessly map whole channel networks with high resolution. Data can be contoured to a 25 cm interval. Slow and expensive traditional field surveyed cross sections would have provided only a fraction of the topographic detail in this single short channel reach.
Channel and adjacent floodplain topographic map made from EAARL data.
Airphoto - Bearskin Cr., Upper Middle Fork Salmon River, Idaho
Using field surveys, an unusually intensive channel survey would be required to produce even less topographic detail for just one small stream reach like this one: • 300 m Long Reach • Average Channel Width = 15 m • 40 Cross Sections (0.5 channel width interval) • 2-Person Field Survey Crew • 40 hours @ $15/hr X 2 people = $1,200
Possible Project Outcomes: • Revolutionary improvement in channel habitat inventory and monitoring; seamless, precise and consistent, high resolution mapping of major portions of channel networks; new analyses of habitat use and population dynamics of aquatic species.
Contact: Jim McKean, USDA Forest Service, RMRS, Boise. Phone (208) 373-4383.
[email protected] 
