abstract limitations of traditional (conventional) soil surveys and improvement of information technology have lead soil surveyors to invent new methods which are generally called digital soil mapping (dsm). the aim of these methods is the prediction of soil classes or soil properties based on easily-available or measuring environmental variables. the objective of this investigation is to study...

the objective of this study is evaluation of topographic wetness index (twi) using attraction model in northern of fars province. the first attraction model was used to enhance the spatial resolution of digital elevation model (dem). in this research to estimate of value of sub-pixels neighboring pixels, touching and quadrant neighboring models were used. after manufacturing output images for s...

Digital Elevation Model (DEM) is the core data for three-dimensional visualization and geographical spatial analysis. With the implementation of Digital Earth, the amount of various DEM data is rapidly expanding. In order to compress DEM data, researchers ever put forward two kinds of DEM compression methods: Generic entropy encoding compression; Converting grid DEM to TIN DEM [1][2]. In recent...

Terrain modeling is a fast growing field with many applications such as computer graphics, resource management, Earth and environmental sciences, civil and military engineering, surveying and photogrammetry and games programming. One of the most widely used terrain model is the Digital Elevation Model (DEM). A DEM is a simple regularly spaced grid of elevation points that represent the continuo...

A Digital Elevation Model (DEM) refers to a quantitative model of a part of the earth’s surface in digital form (Burrough and McDonnell, 1998). A DEM consists of either (1) a twodimensional array of numbers that represents the spatial distribution of elevations on a regular grid; (2) a set of x, y, and z coordinates for an irregular network of points; or (3) contour strings stored in the form o...

There are many kinds of DEM (Digital Elevation Model) generation methods such as a stereomatching from aerial photograph or satellite image, an interferometry from SAR data and an interpolation of topographic maps. On the other hand, we can use some accomplished DEMs. For example, NGDC NOAA offers global land one-km base elevation (GLOBE). And USGS offers Digital Chart of the World that has ele...