Digital elevation model (DEM) is one of the most important datasets for the greater part of spatial-based studies and research. Generally, a high quality DEM could be used as all-purpose dataset, but unfortunately its production could be very expensive. If we know a nature of application that applies DEM, if our demands for the final result are clear, and if provider of DEM gives enough clear i...

Two methods of grid based and image based modeling were put forward respectively to represent the landform of watersheds on the Loess Plateau, China. Many kinds of spatial data such as Digital Elevation Model (DEM), Remote Sensing (RS) images, and photos are utilized to establish the digital 3-D terrains of watersheds on the Loess Plateau, which provides 3-D virtual geographic environments for ...

Topographic parameters in glacier inventories are a requirement to analyze glacier characteristics and are of vital importance for several subsequent applications. To obtain the topographic information a digital elevation model (DEM) is required; however, in many regions of the world no national or local DEM of sufficient quality is available. With the SRTM DEM and the ASTER Global Digital Elev...

Algorithms are presented which use a digital elevation model (DEM) to extract topographic patterns. The algorithms have been applied to extracting natural topographic automatically from the regular grid DEM of a testing area. The experimental results have proved that the automatic extracting algorithms are effective.

At present, most of the digital data acquisition methods generate Digital Surface Model (DSM) and not a Digital Elevation Model (DEM). Conversion from DSM to DEM still has some drawbacks, especially the removing of off terrain point clouds and subsequently the generation of DEM within these spaces even though the methods are automated. In this paper it was intended to overcome this issue by att...

Mathematical problems of digital terrain analysis include interpolation of digital elevation models (DEMs), DEM generalization and denoising, and computation of morphometric variables by calculation of partial derivatives of elevation. Traditionally, these procedures are based on numerical treatments of two-variable discrete functions of elevation. We developed a spectral analytical method and ...

Loci of extreme curvature of the topographic surface may be defined by the derivation function (T) depending on the first-, second-, and third-order partial derivatives of elevation. The loci may partially describe ridge and thalweg lines. The firstand second-order partial derivatives are commonly calculated from a digital elevation model (DEM) by fitting the second-order polynomial to a 363 wi...

Digital Elevation Models (DEMs) including Advanced Spaceborne Thermal Emission and Reflection Radiometer-Global Digital Elevation Model (ASTER GDEM), Shuttle Radar Topography Mission (SRTM), and Global Multi-resolution Terrain Elevation Data 2010 (GMTED2010) are freely available for nearly the entire earth’s surface. DEMs that are usually subject to errors need to be evaluated using reference e...

The use of aerial photographs, satellite images, scanned maps and digital elevation models necessitates the setting up of strategies for the storage and visualization of these data in an interactive way. In order to obtain a three dimensional visualization it is necessary to map the images, called textures, onto the terrain geometry computed with Digital Elevation Model (DEM). Practically, all ...

In this work, a new partition-collocation strategy for the parallel execution of CFD–DEM couplings is investigated. Having a good parallel performance is a key issue for an Eulerian-Lagrangian software that aims to be applied to solve industrially significant problems, as the computational cost of these couplings is one of their main drawback. The approach presented here consists in co-locating...