Chapter 1 Geomorphometry: A Brief Guide

Publisher Summary Geomorphometry is the science of quantitative land-surface analysis. It evolved directly from geomorphology and quantitative terrain analysis, two disciplines that originated in 19th century geometry, physical geography, and the measurement of mountains. Modern geomorphometry addresses the refinement and processing of elevation data, description and visualization of topography, and a wide variety of numerical analyses. It focuses on the continuous land-surface, although it also includes the analysis of landforms, discrete features, such as watersheds. The operational goal of geomorphometry is extraction of measures and spatial features from digital topography. Geomorphometry supports countless applications in the Earth sciences, civil engineering, military operations, and entertainment. Geomorphometric analysis commonly entails five steps: Sampling a surface, generating and correcting a surface model, calculating land-surface parameters or objects, and applying the results. The three classes of parameters and objects include both landforms and pointmeasures, such as slope and curvature. Landform elements are fundamental spatial units having uniform properties. Complex analyses may combine several parameter maps and incorporate non-topographic data. The procedure that extracts most land-surface parameters and objects from a digital elevation model (DEM) is the neighborhood operation. Because parameters can be generated by different algorithms or sampling strategies, and vary with spatial scale, no DEM-derived map is definitive.