Reliability assessment of three topographic methods for generating digital elevation models (DEMs)

Introduction: A digital elevation model (DEM) allows for the analysis of specific features on the earth’s surface in three dimensions. The engineering DEM is useful to evaluate resources and design management strategies. Objective: To evaluate the technical-operational feasibility of generating DEMs from total station (TS) topographic surveys, GPS RTK and aerial photogrammetry using an unmanned aerial vehicle (UAV). Methodology: A 20x20 m grid was traced in a plot without vegetation (1.4 ha) located in Montecillo, Estado de México, and topographic surveys were carried out with three methods, from which DEMs were generated for graphic and statistical evaluation and by tracing contour lines. Results: The estimated statistical errors were 0.15, 0.15 and 0.02 m, for TS vs. UAV, GPS RTK vs. UAV and TS vs. GPS RTK, respectively. Study limitations: The instruments used and the geographical conditions of central Mexico may be a reason for variation when extrapolating the results with other devices. Originality: A methodology is provided to generate DEMs accurately. The results allow the user to make reasoned choices based on the equipment available. Conclusion: The DEMs generated with TS and GPS RTK data have a smaller error than the one obtained from UAVs. The use of UAV helps in the representation of the terrain, since it generates a dense cloud of points that strengthens the procedure for topographic surveys.

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Urban Flood Mapping

10.31227/osf.io/mc2p5 ◽

2017 ◽

Author(s):

Indra Riyanto ◽

Lestari Margatama

Keyword(s):

Natural Disasters ◽

Satisfying Condition ◽

Three Dimensions ◽

Urban Flood ◽

Digital Elevation ◽

Elevation Data ◽

Recent Occurrence ◽

Elevation Model ◽

Digital Elevation Model Data ◽

Potential Area

The recent degradation of environment quality becomes the prime cause of the recent occurrence of natural disasters. It also contributes in the increase of the area that is prone to natural disasters. Flood history data in Jakarta shows that flood occurred mainly during rainy season around January – February each year, but the flood area varies each year. This research is intended to map the flood potential area in DKI Jakarta by segmenting the Digital Elevation Model data. The data used in this research is contour data obtained from DPP–DKI with the resolution of 1 m. The data processing involved in this research is extracting the surface elevation data from the DEM, overlaying the river map of Jakarta with the elevation data. Subsequently, the data is then segmented using watershed segmentation method. The concept of watersheds is based on visualizing an image in three dimensions: two spatial coordinates versus gray levels, in which there are two specific points; that are points belonging to a regional minimum and points at which a drop of water, if placed at the location of any of those points, would fall with certainty to a single minimum. For a particular regional minimum, the set of points satisfying the latter condition is called the catchments basin or watershed of that minimum, while the points satisfying condition form more than one minima are termed divide lines or watershed lines. The objective of this segmentation is to find the watershed lines of the DEM image. The expected result of the research is the flood potential area information, especially along the Ciliwung river in DKI Jakarta.

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Morphometric analysis and prioritization of upper Benue River watershed, Northern Nigeria

Applied Water Science ◽

10.1007/s13201-021-01364-x ◽

2021 ◽

Vol 11 (2) ◽

Author(s):

Caleb Akoji Odiji ◽

Olaide Monsor Aderoju ◽

Joseph Bisong Eta ◽

Idris Shehu ◽

Adama Mai-Bukar ◽

...

Keyword(s):

Management Strategies ◽

Decision Makers ◽

Order System ◽

Hydrological Process ◽

Drainage Pattern ◽

River Watershed ◽

Digital Elevation ◽

Hypsometric Integral ◽

Cumulative Length ◽

Elevation Model

AbstractThe upper Benue River watershed is undergoing remarkable modifications due to man-made and natural phenomena. Hence, an evaluation is required to understand the hydrological process of the watershed for planning and management strategies. This study aimed to assess the morphometric characteristics and prioritize the upper Benue River watershed. The boundary of the watershed and sub-watersheds, as well as stream networks, was extracted from the digital elevation model (DEM) coupled with hydrological and topographic maps. Twenty-eight morphometric parameters under three categories, i.e. linear, areal, and relief aspects were computed and mapped. Findings from the study revealed that the watershed is a seventh stream order system characterized by a dendritic drainage pattern. The result also showed that 4821 streams were extracted with a cumulative length of 30,232.84 km. The hypsometric integral of the watershed was estimated to be 0.22, indicating that it is in the old stage. In the prioritization of the watershed, the morphometric variables were utilized to calculate and classify the compound factor. The result showed that sub-watersheds 12, 16, 18, 24, 26, and 27 were ranked as very high priority for which conservation measures are required to mitigate the risk of flood and erosion. The outcome of this study can be used by decision-makers for sustainable watershed management and planning.

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Spatial Analysis Using Temporal Point Clouds in Advanced GIS: Methods for Ground Elevation Extraction in Slant Areas and Building Classifications

ISPRS International Journal of Geo-Information ◽

10.3390/ijgi8030120 ◽

2019 ◽

Vol 8 (3) ◽

pp. 120 ◽

Cited By ~ 16

Author(s):

Sara Shirowzhan ◽

Samad Sepasgozar

Keyword(s):

Digital Elevation Model ◽

Urban Growth ◽

Urban Areas ◽

Future Directions ◽

3D Data ◽

Contour Lines ◽

Digital Elevation ◽

The Future ◽

Elevation Model ◽

Skewness And Kurtosis

Deriving 3D urban development patterns is necessary for urban planners to control the future directions of 3D urban growth considering the availability of infrastructure or being prepared for fundamental infrastructure. Urban metrics have been used so far for quantification of landscape and land-use change. However, these studies focus on the horizontal development of urban form. Therefore, questions remain about 3D growth patterns. Both 3D data and appropriate 3D metrics are fundamentally required for vertical development pattern extraction. Airborne light detection and ranging (Lidar) as an advanced remote-sensing technology provides 3D data required for such studies. Processing of airborne lidar to extract buildings’ heights above a footprint is a major task and current automatic algorithms fail to extract such information on vast urban areas especially in hilly sites. This research focuses on proposing new methods of extraction of ground points in hilly urban areas using autocorrelation-based algorithms. The ground points then would be used for digital elevation model generation and elimination of ground elevation from classified buildings points elevation. Technical novelties in our experimentation lie in choosing a different window direction and also contour lines for the slant area, and applying moving windows and iterating non-ground extraction. The results are validated through calculation of skewness and kurtosis values. The results show that changing the shape of windows and their direction to be narrow long squares parallel to the ground contour lines, respectively, improves the results of classification in slant areas. Four parameters, namely window size, window shape, window direction and cell size are empirically chosen in order to improve initial digital elevation model (DEM) creation, enhancement of the initial DEM, classification of non-ground points and final creation of a normalised digital surface model (NDSM). The results of these enhanced algorithms are robust for generating reliable DEMs and separation of ground and non-ground points in slant urban scenes as evidenced by the results of skewness and kurtosis. Offering the possibility of monitoring urban growth over time with higher accuracy and more reliable information, this work could contribute in drawing the future directions of 3D urban growth for a smarter urban growth in the Smart Cities paradigm.

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Study on the Utilization of Digital Elevation Model for Calculation Method of Reservoir Capacity

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.472-475.1627 ◽

2012 ◽

Vol 472-475 ◽

pp. 1627-1631

Author(s):

Li Fang Lai ◽

Yu Fen Zhang

Keyword(s):

Digital Elevation Model ◽

Calculation Method ◽

Reservoir Capacity ◽

Contour Lines ◽

Digital Elevation ◽

Capacity Calculation ◽

Elevation Model

Reservoir capacity is a very important parameter for reservoir. This paper discusses the use of contour lines to establish digital elevation model (DEM) of reservoir, and to calculate reservoir capacity to improve the accuracy of the capacity calculation through the method that uses digital elevation model.

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COMPARATIVE ANALYSIS FOR METHODS OF BUILDING DIGITAL ELEVATION MODELS FROM TOPOGRAPHIC MAPS USING GEOINFORMATION TECHNOLOGIES

Geodesy and Cartography ◽

10.3846/gac.2021.13208 ◽

2021 ◽

Vol 47 (4) ◽

pp. 191-199

Author(s):

Vadim Belenok ◽

Yuriy Velikodsky ◽

Oleksandr Nikolaienko ◽

Nataliia Rul ◽

Sergiy Kryachok ◽

...

Keyword(s):

Digital Elevation Models ◽

Complex Structure ◽

Topographic Maps ◽

Interpolation Methods ◽

Contour Lines ◽

Central Russian Upland ◽

Digital Elevation ◽

Elevation Data ◽

The Russian Federation ◽

Elevation Model

The article considers the question of estimating the accuracy of interpolation methods for building digital elevation models using Soviet topographic maps. The territory of the Kursk region of the Russian Federation was used as the study area, because it is located on the Central Russian Upland and characterized by the complex structure of the vertical and horizontal dissection of the relief. Contour lines automatically obtained using a Python algorithm were used as the initial elevation data to build a digital elevation model. Digital elevation models obtained by thirteen different interpolation methods in ArcGIS and Surfer software were built and analyzed. Special attention is paid to the ANUDEM method, which allows to obtain hydrologically correct digital elevation models. Recommendations for the use of one or another method of interpolation are given. The results can be useful for professionals who use topographic maps in their work and deals with the design using digital elevation models.

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Visualizations of the Doblar Accumulation Basin Based on the UAV Survey

Advances in Cartography and GIScience of the ICA ◽

10.5194/ica-adv-1-8-2019 ◽

2019 ◽

Vol 1 ◽

pp. 1-7

Author(s):

Klemen Kozmus Trajkovski ◽

Gašper Štebe ◽

Dušan Petrovič

Keyword(s):

3D Model ◽

Weather Conditions ◽

Point Clouds ◽

Water Levels ◽

Contour Lines ◽

Digital Elevation ◽

Short Period ◽

Dense Point ◽

Aerial Vehicle ◽

Elevation Model

<p><strong>Abstract.</strong> Our research is based on a large case study of Unmanned Aerial Vehicle (UAV) surveys, modelling and visualizations of the Doblar accumulation basin. The various approaches for UAV surveying of large, demanding terrain configurations, and the benefits of surveying products used as a basis for other interdisciplinary hydrological and environmental services were researched. The demanding mountainous terrain, the steep slopes and deep and narrow streams required detailed pre-planning of the survey, including the pre-survey terrain overview. The accumulation basin was emptied merely for a short period; thus, the survey was performed in unfavourable weather conditions, which included coldness, snowfall and wind. Point clouds were generated and georeferenced from the 4377 recorded photos. The dense point cloud contained approximately 222 million points in the medium setting and more than a billion in the high setting. A 3D model was built from the data. This became the basis for numerous further analyses and for the presentation using cartographic principles: a digital elevation model with a resolution of 10&thinsp;cm, an orthophoto with a resolution of 10&thinsp;cm, a 3D model draped with orthophoto, contour lines with a 1&thinsp;m interval, topographic profiles, calculations of volumes at different water levels, a flythrough, augmented reality and a video simulation of the water level changes. The model can also serve as a basis for hydraulic and environmental analysis and simulations or used for analyses of the accumulation and deposition of river material compared with previous and future surveys.</p>

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Study of Watershed Image Segmentation for Flood Potential Area Mapping in Jakarta. Case Study: Ciliwung River–West Banjir Kanal

10.31227/osf.io/wxnpg ◽

2017 ◽

Author(s):

Indra Riyanto ◽

Lestari Margatama

Keyword(s):

Natural Disasters ◽

Satisfying Condition ◽

Three Dimensions ◽

Digital Elevation ◽

Elevation Data ◽

Recent Occurrence ◽

Elevation Model ◽

Digital Elevation Model Data ◽

Set Of Points ◽

Potential Area

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استخدام نظم المعلومات الجغ ا رفية في إنشاء نموذج ارتفاع رقمي للكثبان الرملية

Muthanna Journal of Engineering and Technology ◽

10.52113/3/mjet/2013-1-1/14-21 ◽

2013 ◽

Vol 1 (1) ◽

pp. 14-21

Author(s):

Hussein M. Al-Khuzaie ◽

Qassim J. Salman

Keyword(s):

Sand Dunes ◽

Google Earth ◽

Digital Information ◽

Space Images ◽

Contour Maps ◽

Contour Lines ◽

Digital Elevation ◽

Gis Technique ◽

City District ◽

Elevation Model

"In GIS, it is essential to use the areal and space images as data references for information, but it is necessary to create digital information using software such as SURFER 8 and ARC view. These data can be furnished to create digital contour lines map in a rapid way rather than the conventional methods. In this paper, GIS technique was used for producing 3 dimension contour maps for earth surface. This was called as Digital Elevation Model that can provide a view for spatial coordination for the location of these maps. The area was selected for this study is the sand dunes area at Al.Mamlaha (Samawa city district). The source of space images was Google Earth ."

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Progress in the Reconstruction of Terrain Relief Before Extraction of Rock Materials—The Case of Liban Quarry, Poland

Remote Sensing ◽

10.3390/rs12101548 ◽

2020 ◽

Vol 12 (10) ◽

pp. 1548 ◽

Cited By ~ 1

Author(s):

Roksana Zarychta ◽

Adrian Zarychta ◽

Katarzyna Bzdęga

Keyword(s):

Open Pit ◽

Open Pit Mining ◽

Topographic Map ◽

Estimation Errors ◽

Mining Areas ◽

Contour Lines ◽

Digital Elevation ◽

The Difference ◽

Elevation Model ◽

Topographical Relief

Open pit mining leads to irreversible changes in topographical relief, which makes a return to the original morphology virtually impossible. This is important for quarries that were part of former mining areas. This research presents an innovative approach to the reconstruction of the relief of anthropogenically transformed land on the example of Liban Quarry in Cracow, where operations began before 1873 to 1986. The basis for the reconstructed area was a Topographic Map of Poland with a scale 1:10,000 from 1997, from which a set of data was obtained to perform spatial analyses. The estimation was conducted using the ordinary kriging method, enabling a reconstruction of the morphology of the studied area and presenting it in the form of a hypsometric map and a digital elevation model. The correctness of the modelling was verified by cross-validation and a kriging standard deviation map (SDOK). These revealed low values of estimation errors in the places without contour lines on the base map. The comparison of the obtained maps and model with a Tactical Map of Poland with a scale 1:100,000 from 1934 indicated great similarities. The highest interpolation error value was recorded in the part of the pit where the difference between the actual and reconstructed elevation was about 30 m on average. In the exploited part, the SDOK did not exceed 0.52 m, and in the entire studied area, it reached a maximum of 0.56 m. The proposed approach fulfilled the assumptions of reconstruction, as the analysis revealed elements matching the historic relief in both forms of presentation of the topography of the quarry, on the obtained hypsometric map and on the tactical map. Our study is among the very few in the world concerning the application of geostatistics in the restoration of the relief of land transformed by open pit mining activities.

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Map of the terminal moraine of the Werenskioldbreen glacier (South-West Spitsbergen) from 2015

E3S Web of Conferences ◽

10.1051/e3sconf/20182900029 ◽

2018 ◽

Vol 29 ◽

pp. 00029 ◽

Cited By ~ 1

Author(s):

Laura Downar-Zapolska ◽

Tadeusz Głowacki

Keyword(s):

Complex Terrain ◽

Large Scale ◽

Terminal Moraine ◽

Topographic Features ◽

Contour Lines ◽

Digital Elevation ◽

Field Notes ◽

Glacial River ◽

Elevation Model ◽

West Spitsbergen

The first direct field measurement of the entire terminal moraine of the Werenskioldbreen glacier on Spitsbergen took place at the end of July and the beginning of August 2015. The results of the measurements were the basis for the development of the large-scale terminal moraine map. The article presents the stages of map creation and editing based on measurement points established by the GNSS method. The map editing required knowledge of the morphologically complex terrain. Key documentation was field notes and documentary photographs, enabling the cartographic interpretation of the varied topographic features of the terrain's surface. Based on the documentation, the water bodies on the moraine were located, the outline of the structure and the boundary points were executed and the latter were excluded from the triangulation process. The glacial river was also excluded from triangulation, which allowed a DTM to be developed. An important step in point cloud mapping was to generate a topologically correct digital elevation model of satisfactory accuracy. On the basis of the DTM, contour lines were generated showing the topographic features of the terrain's surface. The printable resultant map's scale is 1: 5000; it is in the UTM coordinate system, in the 33X zone. Complementing the content of the map, a grid of geographic coordinates, a kilometer grid, and map key descriptions were added.

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