Application of topographic analyses for mapping spatial patterns of soil properties

Authors: LI, X - US Department Of Agriculture (USDA); McCarty, Gregory

Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 5/20/2019
Publication Date: N/A
Citation: N/A

Interpretive Summary: Landscape topography is a key parameter influencing biogeochemical processes that occur in the near-surface layer of the earth. The topography plays an important role in soil formation through regulating soil hydrological regimes and controlling gravity-driven soil movement. Quantitative and qualitative topographic information is essential in understanding the heterogeneity of soil chemistry and physics. Along with developments in computer, aerial, space, and geographic technologies, the availability of high-resolution Digital Elevation Models (DEMs) introduces a new source for deriving Digital Terrain Models (DTMs) and has been the main source for topographic information extraction in soil biogeochemical studies since the 1990s. This chapter addresses applications of topographical information for mapping spatial patterns of soil properties in recent years. Objectives of this chapter are to provide an overview of 1) impacts of topographic heterogeneity on the spatial variability in soil properties; and 2) commonly used topography-based models in soil science. A case study is provided to demonstrate the feasibility of applying topography-based models developed in field sites to predict soil properties at the watershed scale. A large-scale soil property map is obtained based on topographic information derived from high-resolution remotely sensed data, which benefits studies in areas with limited data access or where representative site findings are extrapolated to larger regions. Improved maps of soil properties for agricultural lands should improve our ability to represent soil processes in both landscape and watershed models.

Technical Abstract: Landscape topography is a key parameter impacting soil properties on the earth surface. Strong topographic controls on soil morphological, chemical, and physical properties have been reported. This chapter addressed applications of topographical information for mapping spatial patterns of soil properties in recent years. Objectives of this chapter are to provide an overview of 1) impacts of topographic heterogeneity on the spatial variability in soil properties and 2) commonly used topography-based models in soil science. A case study was provided to demonstrate the feasibility of applying topography-based models developed in field sites to predict soil property over a watershed scale. A large-scale soil property map can be obtained based on topographic information derived from high-resolution remotely sensed data, which would benefit studies in areas with limited data accesses or needed to extrapolate findings from representative sites to larger regions.