Quantifying terrain fabric in digital elevation models
Eigenvector analysis of a topographic landform reveals a directional fabric consisting of surface roughness or slope, organization or fabric strength, and preferred orientation. This analysis uses a digital elevation model (DEM) to compute slope and aspect at all points in a region and uses those values to define the normal surface. Standard techniques contour the distributions, extract eigenvectors and eigenvalues from the matrix of the sum of cross products of the directional cosines, and compute eigenvalue ratios. The terrain fabric at a point depends on the size of the region used for the computation and reveals different scales over which directional fabrics operate. With large-scale DEMs, the directional fabric varies in a systematic manner and proves relatively insensitive to the horizontal resolution of the DEM or its quality and creation method. Quantitative measurement of terrain fabric belongs in all studies of terrain analysis and geomorphometry.
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The Environmental Legacy of Military Operations
Military geology comprises research and practical efforts directed toward providing geological input for military construction, civil works projects (e.g., dams, navigable waterway maintenance), remediation of polluted military facilities, terrain analysis, sustainability of training lands, mobility prediction, and site characterization activities. Land use sustainability issues, base closures, and heightened levels of environmental awareness by the general public have introduced new challenges for using, maintaining, cleaning, and restoring lands that have served as military installations for decades. In this volume, the legacy of military operations and their impact on the terrain and geology, particularly from an environmental viewpoint, are considered by geologists of diverse lands and backgrounds. This book, a companion volume to Military Geology in War and Peace (Reviews in Engineering Geology, v. 13, 1998), emphasizes current research and applications of engineering geology principles and practice to modern day military problems, many of which are environmental in nature.