Light Detection & Ranging (LiDAR) – Enhanced Forest Inventory Prepared by Christopher Butson & Xiaoping Yuan Forest Analysis and Inventory Branch (FAIB)

Scope of Discussion The operational LiDAR players in B.C. include, FAIB – Forest Analysis & Inventory Branch BCTS – British Columbia Timber Sales Licensees – Forest companies including Canfor, Western Forest Products etc.

FAIB Mandate Collect and maintain provincial forest inventories Monitor the growth and disturbance of stands over time and, Provide analytical support (data collection, statistical and strategic analysis) for the B.C resource sector.

LiDAR topics for discussion Inventory tool chain What are they inventorying? Who are they serving? What outputs are they producing? How do they deal with species? How do they integrate outputs with an existing system? Highest priorities for improvements?

Lastools 1. EFI Flow Chart: Lastools/FUSION R ArcGIS

Ground filtering artifacts Atmospheric noise Ground filtering artifacts DEM differencing CHM Errors

2. What are they Inventorying? FAIB – We are mainly concerned about timber inventory and terrain modelling. What is it? Where is it? How much is there? Focus on timber big and small.   BCTS/Licensee – Field reconnaissance, terrain and karst modelling, harvest and road layouts, mature timber. Digital Elevation Model TRIM (25m) LiDAR (1m)

3. Who are they serving? FAIB – As a government agency, we serve public interests however, LiDAR activities tend to be industry driven at this time due to their need of operational high resolution terrain and vegetation information. Partnerships are quite common where 1 LiDAR acquisition could be used for multiple purposes.   BCTS/Licensee – Tend to focus on corporate and business needs where LiDAR information can help minimize harvest planning costs, accurately predict stand volume and reduce field reconnaissance and field visits. Added bonus is in reducing environmental risk and improve worker safety.

4. What outputs are they producing? BCTS/Licensee DEM, DSM CHM Tree Top Analysis : then run Density Analysis on taller trees Slope Modelled Harvest Images (3d ArcScene DSMs) Flow Accumulation (streams) Have modelled Karst – potential sink holes (based on DEM) Road Designs in RoadEng Use the EFI volume for estimating values of stands Contours Hillshade FAIB DEM, DSM CHM Inventory rasters: Height, Basal Area, Density, Volume

5. How do they deal with species? FAIB – Currently we are only using existing species information from previous photo interpretation information. BCTS/Licensee – Use existing species information. With higher point densities becoming more common, they have been using software (Object Raku-TSI) to identify species based on crown 3D architecture which leads to the individual tree inventory.

6.How do they integrate with existing systems? FAIB Generalize the LiDAR output rasters to our existing inventory polygons. Main output attributes namely; BA, TPH and HEIGHT Model stand volumes and store in vector GIS.

Integration con’t… BCTS/Licensee – Integrate LiDAR outputs with existing inventory information in a GIS. Also create multi-resolution inventory systems both at the stand level and sub-stand level using LiDAR outputs.

7. Highest priority for improvements? FAIB/BCTS/Licensee – Improvements may include: improving spatial inventory, species recognition, integration with our existing inventory system and, government storage issues. We are also very interested in the transferability of calibration models as our goal is to somehow reduce the cost/dependence of expensive ground sampling in the calibration process. Multi-use forest measurement plots? Can we use variable radius?

Summary: EFI benefits Include more measured data (higher resolution), provide repeatable, objective data output products Statistically driven improvements to generate a range of inventory products, with known accuracy and measured variability Scalability