EVALUATION OF EAARL, AN EXPERIMENTAL BATHYMETRIC AND TERRESTRIAL LIDAR, FOR COLLECTING RIVER CHANNEL TOPOGRAPHY ALONG THE PLATTE RIVER, NEBRASKA

Surveys of river channel topography, which include both submerged and subaerial (floodplain, island and bar) topography, are a critically important aspect of modern river studies. These data are used to detect and quantify changes in bed elevation and channel form and as input to one and/or multi-dimensional hydraulic models. In deep, navigable rivers accurate and efficient techniques for collecting this data with acoustic equipment and conventional surveys are well developed. However, in shallow rivers where navigation is problematic or even impossible, surveys can only be accomplished by wading, which is time consuming and hazardous. The Platte River in central Nebraska is a wide, shallow alluvial river where detailed questions are being asked about the morphology of the river and its relationship to endangered species habitat. Recently NASA has developed a LIght Detection and Ranging system (LIDAR), Experimental Advanced Airborne Research LIDAR (EAARL), for rapidly mapping spatially complex ecosystems containing submerged and/or subaerial topography such as coral reefs, beaches, wetlands, and forests. We present a comparison of topographic data collected by the EAARL system along the Platte River to ground truth measurements made with conventional survey techniques.