Issue link: https://read.dmtmag.com/i/103965
and maintained 3-D landscape model will be more critical for effective emergency management. LiDAR-infused predictive modeling has been a powerful tool in disaster preparation. Recently, the North Carolina Division of Emergency Management developed a methodology to assess the damage of local flooding throughout the state. The agency used a combination of airborne and terrestrial LiDAR to help determine the elevation of the first floor of every building within the state to evaluate flooding impact. Prediction models were run against LiDAR-derived elevation data to create a new model for analyzing flood potential. From its GIS, the division generated digital maps revealing that 5,000 buildings would experience flooding on the first floor as the result of a storm surge. Methodologies such as these allow governments and agencies to equip themselves more strategically, better inform the public about the risks they face and create safer future development plans. The benefit here is immeasurable from a workflow and economic perspective. Forest Management LiDAR also has demonstrated its effectiveness in managing natural resources, such as the world's forests. Integration of optical imagery and LiDAR produces valuable information for forest management and also is used for carbon accounting to understand forest ecosystems. LiDAR now is a crucial tool in refining and creating more-manageable logging practices and operational efficiencies. Before the use of LiDAR in forest monitoring and management, foresters and ecologists had to rely on topographic maps to classify terrain; they had to conduct field-based surveys using ground crews to collect critical information about forest land. Today, aerial LiDAR surveys record the tree canopy as well as penetrate the canopy to return a more accurate interpretation of the ground surface, and those surveys can be used to measure the structure of forest stands and produce models of their underlying terrain. The forest industry requires precise inventories to inform harvesting practices, and LiDAR is its mosteffective technological asset to deliver such precision. Unlike traditional photogrammetric surveys, LiDARderived forest inventories can be taken at a finegrained scale—nearly the single-tree level—offering more accurate depictions of forest land. And now with the introduction of LAS compatibility in a GIS, seamless mosaics of entire LiDAR datasets now can be created, which then can composited with other datasets (e.g., radar and orthophotos) and analyzed with GIS tools. Surface models from LiDAR data then can be stored as terrains in a geodatabase. Imagery/LIDAR Special Issue Pre- and post-Hurricane Sandy LiDAR captures demonstrate a comparative analysis on DTMs revealing that the storm eroded more than 10 feet of dune. Vegetation density and tree height can be estimated, aiding in growth analysis, fertilization plans and harvesting. Large amounts of LiDAR data then can be delivered as seamless datasets to clients and stakeholders, providing higher-quality overall analysis of the forest than would be possible with optical data alone. A GIS provides the framework to combine these datasets for more-comprehensive views of large areas. Such perspectives are invaluable in understanding, managing, and preserving our planet's precious ecology and finite resources. The same synergy that GIS and 2-D imagery share has entered the 3-D age as more individuals and agencies begin to work with LiDAR data. Hopefully, more decision makers investigate this synergistic relationship. We live in a three-dimensional world. The better we can seamlessly incorporate all dimensions into our workflows, the better our future will be. Lawrie Jordan is director of Imagery, Esri; e-mail: ljordan@esri.com. J A N U A R Y 2 O 1 3 / W W W . G E O P L A C E . C O M 25