preparation of the topographic factor (ls) map in rusle model is a very tedious step because of the complicated effects of topography on soil loss. the objective of this study was to determine the suitable cell size of digital elevation model (dem) for computing ls factor by the method of moore and wilson (1992) in a 5326 ha area, northwest of tehran province. towards this end, cell sizes of 30...

Soil Salinity has been a large problem in arid and semi arid regions. Preparation of such maps is useful for Natural resource managers. Old methods of preparing such maps require a lot of time and cost. Multi-spectral remotely sensed dates due to the broad vision and repeating of these imageries is suitable for provide saline soil maps. This investigation is conducted to provide saline soil map...

This study is focused on the evaluation of a Digital Elevation Model (DEM) for Tokyo, Japan from data collected by the recently launched TerraSAR add-on for Digital Elevation Measurements (TanDEM-X), satellite of the German Aerospace Center (DLR). The aim of the TanDEM-X mission is to use Interferometric SAR techniques to generate a consistent high resolution global DEM dataset. In order to gen...

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...

digital elevation model (dem) is increasingly used these days as an effective tool to extract elevation data in quantitative environmental and land management studies. the improvement of sensors and land resource satellites has made it possible to generate dem from remotely sensed data. dems which are produced from these data are applied not only in the two dimensional (2d) but also in the thre...

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 ...

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...

Terrain characteristics, such as slope gradient, slope aspect, profile curvature, contour curvature computed from digital elevation model (DEM), are among the key inputs to digital soil surveys based on geographic information systems (GIS). These terrain attributes are computed over a neighborhood (spatial extent). The objective of this research was to investigate the combi ed effect of DEM res...

Under increased urban settlement density, access to a high resolution (land-parcel scale) bare-earth Digital Elevation Model (DEM) is a pre-requisite for much decision support for planning: stormwater assessment, flood control, 3D visualisation, automatic delineation of flow paths, sub watersheds and flow networks for hydrological modelling. In these terms, a range of options face the DEM-build...