Lidar Use in Soil Survey.

Digital elevation models (DEMs) derived from Light Detection and Ranging (LiDAR) are growing in popularity as a tool for use in soil survey. This form of remotely sensed elevation data can serve multiple purposes, not the least of which is the visual interpretation of landforms and soil parent materials. In 2005, LiDAR elevation data were acquired for Essex County, Vermont, an area of about 1745 km². A procedure was developed for processing the LiDAR data for use in delineating landforms, and for use with the soil inference model ArcSIE. This procedure includes removing spikes (artifacts), filtering, and resampling the data. Different applications require different DEM resolutions to be most effective, and there are no set guidelines for soil survey. The two main uses of the DEM in Essex County are: 1) for visualizing and delineating landforms and parent materials, and 2) deriving terrain attributes for subsequent soil inference in areas of specific parent materials. Thus, it is crucial that the resolution of the DEM allows for accurate delineation of parent materials, since this process provides the basis for ensuing work in the survey area. It was found that the optimum resolution of LiDAR elevation data for soil survey in Essex County was 1m for visualization purposes, and 5m for use with ArcSIE. ArcSIE is used not only for the soil inference itself but for the production of terrain attribute layers used for soil inference and the post processing of the inference results.