Review and critical analysis on digital elevation models (original) (raw)
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An Assessment of Digital Elevation Models (DEMs) From Different Spatial Data Sources
Digital Elevation Model (DEM) represents a very important geospatial data type in the analysis and modelling of different hydrological and ecological phenomenon which are required in preserving our immediate environment. DEMs are typically used to represent terrain relief. DEMs are particularly relevant for many applications such as lake and water volumes estimation, soil erosion volumes calculations, flood estimate, quantification of earth materials to be moved for channels, roads, dams, embankment etc.
International Journal of Research Publication and Reviews, 2024
Flooding is a natural disaster that often occurs and has a significant impact on society and the environment. This can result in economic loss, infrastructure damage, disruption to daily life, and even loss of life. To mitigate the negative impacts of flooding, an in-depth understanding of the potential for flooding in an area is very important. One effective approach is to use spatial modeling to create flood vulnerability models, based on topographic data such as slope maps and contour maps. ALOS PALSAR DEM data, with a spatial resolution of 12.5 meters, offers important advantages in creating slope maps and contour maps for flood potential analysis. As a synthetic aperture radar technology, ALOS PALSAR collects topographic data with high accuracy and wide coverage, even in adverse weather conditions or areas with high cloud cover. Its ability to penetrate clouds makes ALOS PALSAR data more reliable and consistent than optical data, which may be limited by weather conditions. Slope maps show varying degrees of terrain steepness across the study area. Contour lines are successfully created, illustrating elevation changes in the landscape. GIS analysis highlights areas with high slope values and the potential to become flood-prone zones. DEM-derived maps serve as valuable tools for flood vulnerability modeling and risk assessment. Integration of DEM imagery with GIS techniques has proven effective in creating accurate and detailed slope and contour maps. These maps provide important information for identifying flood-prone areas and formulating effective disaster management strategies. This study underscores the importance of terrain analysis in flood vulnerability assessment and emphasizes the usefulness of DEM-derived data for spatial modeling.
Comparative analysis of digital elevation models: A case study around Madduleru River
2017
High resolution DEM is generated from Cartosat-1 stereo data. The performance of different DEMs is evaluated based on error statistics. To identify the hill profiles, the TIN plots have generated and compared for SRTM, Cartosat -1, and SOI toposheet. The study divulges that, elevation values of Cartosat-1 DEM are better in flat terrain and SRTM images in hilly region produced better, when compared each other.
Evaluation of the Accuracy of Digital Elevation Model Produced from Different Open Source Data
Journal of Engineering, 2019
This study aims to estimate the accuracy of digital elevation models (DEM) which are created with exploitation of open source Google Earth data and comparing with the widely available DEM datasets, Shuttle Radar Topography Mission (SRTM), version 3, and Advanced Spaceborne Thermal Emission and Reflection Radiometer Global Digital Elevation Model (ASTER GDEM), version 2. The GPS technique is used in this study to produce digital elevation raster with a high level of accuracy, as reference raster, compared to the DEM datasets. Baghdad University, Al Jadriya campus, is selected as a study area. Besides, 151 reference points were created within the study area to evaluate the results based on the values of RMS. Furthermore, the Geographic Information System (GIS) was utilized to analyze, imagine and interpolate data in this study. The result of the statistical analysis revealed that RMSE of DEM related to the differences between the reference points and Google Earth, SRTM DEM and ASTER GDEM are 6.9, 5.5 and 4.8, respectively. What is more, a finding of this study shows convergence the level of accuracy for all open sources used in this study.
Suitable digital elevation model
2005
A high quality DEM could be generally used as all-purpose dataset, but unfortunately its production could be very expensive. If we know a nature of application that applies DEM and if our demands for the final result are clear, then we can adjust the DEM selection or we can simplify its production.
2014
ABSTARCT Ground surveying methods are main sources for digital elevation data that is usually utilized in the creation of a Digital Elevation Model (DEM). DEM usually is a main input in many Engineering and Environmental applications. The quality of the DEM is a vital issue that controls the qualities of outputs in different applications. Different factors including the data source, the data density, the sampling method, the spatial resolution and the interpolation scheme control the quality of the DEM. This research is focused towards investigating the effects of the spatial resolution of the DEMs generated from ground surveying data on their qualities where digital elevation data has been collected from a test area of corrugated terrain using ground surveying methods. Qualitative and quantitative analyses have been applied on DEMs created from digital elevation data with different resolutions through; visual analysis, statistical analysis, profile analysis and finally accuracy ass...
Advances in Remote Sensing, 2018
Accuracy and quality of DEM are of a great interest for a wide range of applications. In this study, quality of ASTER GDEM and SRTM DEMs were assessed in comparison with DGPS measurements. Impact of DEM resolution upon the accuracy of terrain representation and topographic attributes was also discussed. The study deduced that vertical error has a strong effect on error propagation and this highly obvious in higher elevations as the absolute standard error (SE) ranges between is ±0-2.5 and ±0-2.4 m for ASTER GDEM and SRTM respectively. This is reflected on slope and aspect as the vertical errors increase and uncertainty is relatively high in flat and low areas. Error propagation in low lands influenced drainage extraction and resulted in isolated and truncated water courses.
2018
A high accuracy Digital Elevation Model (DEM) for the Nile delta region, Egypt is needed for several environmental applications, particularly for investigating the hazardous impacts of sea level rise and land subsidence phenomena. Since there is no official published national DEM for Egypt, an original high accuracy local digital elevation model (LDEM) for that region has been created using nine Spatial Interpolation Methods (SIMs) within a Geographic Information Systems (GIS) environment. The interpolation process took place after digitizing over than 220 topographic maps of scale 1:25,000, where more than 810,000 elevation (spot heights) points have been extracted from these maps. Multiple parameters and criteria for each SIM were applied to reach the optimal settings to produce a LDEM for environmental applications. The developed LDEMs have been compared against eight free Global Digital Elevation Models (GDEMs) using about 200 known GPS/levelling Ground Control Points (GCPs), wh...
Evaluation Digital Elevation Model Generated by Synthetic Aperture Radar Data
ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 2016
Digital elevation model, showing the physical and topographical situation of the earth, is defined a tree-dimensional digital model obtained from the elevation of the surface by using of selected an appropriate interpolation method. DEMs are used in many areas such as management of natural resources, engineering and infrastructure projects, disaster and risk analysis, archaeology, security, aviation, forestry, energy, topographic mapping, landslide and flood analysis, Geographic Information Systems (GIS). Digital elevation models, which are the fundamental components of cartography, is calculated by many methods. Digital elevation models can be obtained terrestrial methods or data obtained by digitization of maps by processing the digital platform in general. Today, Digital elevation model data is generated by the processing of stereo optical satellite images, radar images (radargrammetry, interferometry) and lidar data using remote sensing and photogrammetric techniques with the he...
Generation and Accuracy Assessment of Digital Elevation Models in Mountain Area
2015
Nowadays DEMs are indispensable tools in studies and analysis regarding Earth’s surface. Generating DEMs closely to the true surfaces and with high accuracy represent a main issue. The aim of the study is to improve the geomorphometric analysis based on DEMs. In this study a statistical approach was used to assess various DEMs generated with different methods to compare their accuracy. DEMs were created on the base of a topographic map using classical interpolation methods (Spline, IDW, Kriging, Simple linear interpolation) and simulated surfaces. The results suggest that data source is more important in error propagation, followed by interpolation methods.