| Popis: |
Predicting soil physical and chemical properties for military operations requires knowledge of the geologic and lithologic component of the soil parent material. Geologic maps, a traditional source of geologic information, are often limited in coverage or inadequate for determining the basic characteristics of a soil parent material. We describe an approach for the rapid development of geologic surface maps that identify the lithologic composition of soil parent material generated from ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) data. Generated maps of parent material, in turn, provide key input parameters for a comprehensive terrain predictive model that forecasts key soil and surface cover characteristics in support of military operations. Parent material maps are generated using a multilayer approach where calibrated image data are mapped into lithologic units that best identify soil parent material and corresponding landform units (i.e. bedrock, fan, playa, dune, etc.). A unique and critical aspect of our approach is that expert-based analysis of spectral and geospatial information can produce a geologic map, covering 1000–5000 km2 of terrain, of soil parent material and surface cover in as little time as nine staff-hours. The approach was developed with a guiding principle that terrain predictions in military operations must be rapidly developed for areas where available ground information is limited. Results indicate that it is possible to quickly produce a realistic map of soil parent material using ASTER data without any additional geologic information or data. Results also indicate that analysts developing parent material maps require expert knowledge in both spectral analysis of remotely sensed data and the geologic and geomorphic processes that form desert landforms. |
