干旱区生态环境知识资源中心

Unlike most of the USA, the western region still lacks initial soil mapping on many private and public lands. Spatially explicit soil data are needed to support a variety of land uses including energy development, mining, grazing, agriculture, forest products, recreation, wildlife habitat, species conservation and urban development. The wide diversity of lithology, geomorphology, climate, and vegetation and the vast, difficult-to-access terrain of western landscapes facilitated the development of digital soil mapping. Environmental covariates used in digital soil mapping in the western USA include derivatives of digital elevations models (DEM) and remotely sensed spectral data (RS). DEM-derived data are often used to represent climate and relief (geomorphology, microclimate). The low vegetation cover of arid, semiarid, and seasonally dry climates typical of the West facilitates the use of RS data and its derivatives. Landsat and ASTER data are the most common sources of RS data, and are used to represent organisms (vegetation type and density), parent material (lithology, mineralogy), and soil (mineralogy, wetness, other surface characteristics). Spatially explicit, digital environmental covariates have improved several aspects of soil survey in the western USA including pre-mapping, developing efficient and targeted field sampling plans, and implementation of spatial prediction models.