Delineating and Evaluating Vegetation Conditions of Vernal Pools Using Spaceborne and Airborne Remote Sensing Techniques, Beale Air Force Base, CA

Remote sensing techniques were employed to identify aquatic resources, including vernal pools and riparian areas, at Beale Air Force Base (AFB) in September 2005. Aquatic resources previously identified at Beale AFB were delineated in the field and precisely located with a global position system (GPS). Though precise, these GPS maps were not comprehensive enough to fully understand the distribution and character of the aquatic system. Using those field results, we developed techniques to identify these and similar locations using digitally derived spectral signatures from IKONOS high-resolution multispectral imagery. To refine the delineation results obtained from the multispectral imagery, high-resolution topographic data were acquired over the study area using NASA's Airborne Topographic Mapper (ATM) waveform LiDAR. Using the post-processed digital elevation models (DEM) and a series of statistical approaches, we eliminated many false positive identifications and developed a comprehensive Geographic Information System (GIS) based set of maps for three distinct groupings of vernal pools. These groupings were rated from most similar to previously field-identified vernal pools, to areas with moderate probability to be similar and least similar but still considered areas of interest. The original field mapping results located 244.0 ha of vernal pools and swales; our remote sensing efforts found 411.5 ha. This represents a 169% increase in potential vernal pool locations over the previous estimate. The original document contains color images.