نتایج جستجو برای: digital elevatiom model dem
تعداد نتایج: 2373347 فیلتر نتایج به سال:
The objective of this work is to define procedures to improve spatial resolution of SRTM data and to evaluate their applicability in the Serra Negra region, in the district of Patrocínio, state of Minas Gerais in Brazil. The region's structure is a result of past tectonic processes that have arched it into a dome shape. Besides the already existing agriculture exploitation, Serra Negra also has...
A geographic information system ~GIS! based approach is presented for the development of a terrain model based on stream channel representation of the U. S. Army Corps of Engineers Hydrologic Engineering Center’s River Analysis System ~HEC-RAS! hydraulic model. As input, the approach requires a completed HEC-RAS simulation, a digital elevation model ~DEM!, and a GIS representation of the stream...
The spatial uncertainty of a topography based rainfall runoff model (TOPMODEL) is addressed in this study to assess its variability in simulating watershed hydrologic response with regards to the change of digital elevation model (DEM) resolution. Twelve DEM realizations of different grid sizes ranging from 30 m to 3000 m for each of two case watersheds are used for comparative examinations. Th...
We modeled the extent of inundation around Poyang Lake, China using 13 Landsat images and two digital elevation models (DEMs). Boundaries of the observed inundation extents were (a) labeled with lake-level measurements taken at a representative hydrological station and (b) interpolated to create a Water Line DEM (WL-DEM) that was used to map inundation frequency. A 30 m contour-based DEM produc...
In this paper, a theoretical-empirical model is developed for modelling the accuracy of a grid digital elevation model (DEM) linearly constructed from scattered sample data. The theoretical component integrates sample data accuracy in the model by means of the error-propagation theory. The empirical component seeks to model what is known as information loss, i.e. the sum of the error due purely...
Interferometric synthetic aperture radar (InSAR) processing relies on phase unwrapping to convert interferometric phase to topographic height. Phase unwrapping is a di cult non-linear process that is still the subject of on-going research. Rather than processing the complete phase image to extract a digital elevation model (DEM), we use existing coarse DEMs as an integral part of the InSAR algo...
A hydrologically correct digital elevation model (DEM) forms a basis for realistic environmental modelling, especially in complex terrain. We have performed a study in the Coarse Sandy Hilly Catchments (CSHC) of the Loess Plateau, China, which demonstrates pragmatic, yet effective methods for improving the quality of the DEM by: (1) identifying and correcting source topographic data errors and ...
The need for Digital Elevation Model (DEM) checking has raised since the automated matching techniques emerged. The use of reference data is a luxury and therefore cannot be used in all cases. This article presents a completely new mathematical model, which translates discrepancies between two orthophotographs created from different photographs, into precise corrections of the DEM. These correc...
A digital elevation model (DEM) is a simple representation of a surface in 3 dimensional way with height as the third dimension along with x and y in rectangular axes. DEM has wide applications in various areas like disaster management, hydrology and water management, geomorphology and in urban development. Valuable information about a terrain can be inferred by exploiting a DEM in proper way. ...
Digital Elevation Model is one of the most important data for watershed modeling whit hydrological models that it has a significant impact on hydrological processes simulation. Several studies by the Soil and Water Assessment Tool (SWAT) as useful Tool have indicated that the simulation results of this model is very sensitive to the quality of topographic data. The aim of this study is evaluati...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید