scholarly journals Upgrade of existing algorithms for creating contour lines on topographic maps of the karst surface

2020 ◽  
Vol 2 ◽  
pp. 1-2
Author(s):  
Neža Ema Komel ◽  
Klemen Kozmus Trajkovski ◽  
Dušan Petrovič
Keyword(s):  
Topographic Maps ◽  
Topographic Map ◽  
Basic Algorithm ◽  
Commercial Software ◽  
Karst Terrain ◽  
Aerial Photos ◽  
Contour Lines ◽  
Elevation Model ◽  
Future Work ◽  
Steep Slopes

Abstract. Today, many software tools enable the production of contour lines from relief models, but the results of modelling complex karst relief are often inadequate. Reasons for this may be limited quality and resolution of relief models, limitations of algorithms for calculating contours, or limitations of algorithms for smoothing and displaying additional symbols that further describe relief, such as slope lines, steep slopes and smaller objects that cannot be effectively displayed with contours, etc.We will present research in the field of improving existing algorithms in rugged karst terrain. As a target result, the presentation of relief on the existing national topographic maps in Slovenia, which were made by manual photogrammetric survey of aerial photos stereo pairs, were used. Slovenian elevation model DMR1 (1 m density) is used as a source for the creation of contour lines in various commercial software packages, and by comparing the results with a relief presentation on a topographic map, we selected the most appropriate basic algorithm. This one is further upgraded mainly by enabling automatic selection of auxiliary contour lines in the area, presentation of individual smaller relief objects with appropriate point or linear symbols, addition of slope lines on contours and indications in the middle of depressions and displacement of contour lines in order to better depict the terrain morphology.The results were tested in four different areas in Slovenia. Figure 1 shows the contour lines for a testing area near village Opatje Selo near Slovenia-Italy border, which were made by the best commercial software. The results of the algorithm are shown in Figure 2. The comparison between the results of the algorithm and the national topographic maps in the chosen scale gave promising results. In future work, we are planning to extend the algorithm so that it will be able to provide modelling of different terrains in the region.

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

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.

Topographic Map Update of Esan Central LGA, Edo State, Nigeria, Using SPOT-5 and ASTER LiDAR Data

2014 ◽  
Vol 1 (1) ◽  
pp. 52-69
Author(s):  
S.O. Ogedegbe
Keyword(s):  
Spatial Data ◽  
Digital Terrain Model ◽  
Topographic Maps ◽  
Lidar Data ◽  
Topographic Map ◽  
Terrain Model ◽  
Digital Elevation ◽  
Système D’Information ◽  
Elevation Model ◽  
Spot 5

This study examines the effectiveness and accuracy of SPOT-5 and ASTER LiDAR data satellite images, Global Pos1t1on1ng System (GPS), Digital Terrain Model (DTM), and Geographic Information System (GIS) in carrying out a revision of Nigerian topographic maps at the scale of 1:50,000. The data for the study were collected by extraction of relevant spatial data from the 1964 topographic map, delineation and interpretation of 2009 SPOT-5 data, and field surveys. The landscape changes extracted from SPOT- 5 were used to update the topographic base map and to determine the nature and direction of changes that have taken place in the study area. The findings revealed that changes have occurred in both cultural and relief features over time. The coefficient of correlation and t-test was calculated to show that changes in point, linear and areal features are significant. Also significant were the planh11etric and height accuracies of the revised map. The study shows that satellite data especially SPOT-5 is useful for the revision of topographic maps at scales of 1:50,000 and even larger. And, high-resolution remote sensing at Sm and ASTER data (30m) with GPS (±1.9m) can be used to c.reate a digital elevation model (DEM) on the map which is an essential dataset for complete revision. Cette étude examine l'efficacité et la précision des images satellites de données SPOT-5 et ASTER LiDAR, du système de positionnement global (GPS), du modèle numérique de terrain (MNT) et du système d'information géographique (SIG) pour effectuer une révision des cartes topographiques nigérianes au échelle de 1:50 000. Les données de l'étude ont été recueillies par extraction de données spatiales pertinentes à partir de la carte topographique de 1964, délimitation et interprétation des données SPOT-5 de 2009 et relevés de terrain. Les changements de paysage extraits de SPOT-5 ont été utilisés pour mettre à jour le fond de carte topographique et pour déterminer la nature et la direction des changements qui ont eu lieu dans la zone d'étude. Les résultats ont révélé que des changements se sont produits dans les caractéristiques culturelles et du relief au fil du temps. Le coefficient de corrélation et le test t ont été calculés pour montrer que les changements dans les caractéristiques ponctuelles, linéaires et aréales sont significatifs. Les précisions planimétriques et altimétriques de la carte révisée étaient également importantes. L'étude montre que les données satellitaires, en particulier SPOT-5, sont utiles pour la révision des cartes topographiques à des échelles de 1:50 000 et même plus. De plus, la télédétection haute résolution aux données Sm et ASTER (30 m) avec GPS (± 1,9 m) peut être utilisée pour créer un modèle d'élévation numérique (DEM) sur la carte qui est un ensemble de données essentiel pour une révision complète.

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

2020 ◽  
Vol 12 (10) ◽  
pp. 1548 ◽  
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.

scholarly journals Studying the development of fluvial landforms in the Berettyó-Körös Region using geoinformatic methods

2016 ◽  
Vol 10 (3-4) ◽  
pp. 137-144
Author(s):  
Csaba Albert Tóth ◽  
Norbert Barkóczi ◽  
Richard William Mcintosh ◽  
Zsolt József Plásztán
Keyword(s):  
Similar Rate ◽  
Topographic Maps ◽  
Mass Movements ◽  
Height Difference ◽  
Aerial Photos ◽  
Geometric Uncertainties ◽  
Contour Lines ◽  
Digital Elevation ◽  
Rtk Gps ◽  
Land Changes

Development of fluvial landforms from 1980 till nowadays was studied based on digital elevation maps(DEM) composed from contour lines of topographic maps, field data obtained by RTK GPS and aerialphotos taken by a drone. Greatest denudation of 6-9 metres was measured in the eastern side of theerosional valley at Pocsaj caused by piping and mass movements. As a result, the valley widened andslightly deepened. Since 1980 around 1-2 metres of accumulation and erosion of similar rate have beenmeasured in the secured floodplain environment dissected by abandoned beds, point-bars and swalesat Kismarja. These values, however, rather reflect the geometric uncertainties and deficiencies of thecontours of topographic maps than real land changes. Therefore topographic maps can give reliable basisfor studying the development of lowland landforms only if they depict adequately large sized (minimum100 x 100 m) positive or negative forms with great height difference as well (minimum 8-10 m). Accuracyof DEMs composed from aerial photos using photogrammetric methods – taking off height faults causedby vegetation – is around the same as that of the models created on the basis of RTK GPS measurements.

scholarly journals Towards sustainable topographic mapping

2019 ◽  
Vol 1 ◽  
pp. 1-1
Author(s):  
Haico van der Vegt ◽  
Ton van Helvert ◽  
Paula Dijkstra
Keyword(s):  
Spatial Data ◽  
Development Stage ◽  
Topographic Maps ◽  
Topographic Mapping ◽  
Topographic Map ◽  
Sources Of Information ◽  
The Sustainable Development ◽  
Aerial Photos ◽  
The World ◽  
The Government

<p><strong>Abstract.</strong> “Everything happens somewhere”, a popular phrase nowadays to emphasize the importance of good and reliable geographic information. National Spatial Data Infrastructures (NSDI) are popping up in many countries in the world as governments realize that a wealth of geo-data is produced, but that this data is not known or available to other organizations. An NSDI channels this information to the users. Availability of geo-information and efficiency in the production are the key drivers.</p><p>Another big driver is the Sustainable Development Goals (SDG). To monitor the development of the progress of the SDG’s, a wealth of statistical information on economic, social and environmental phenomena is collected. All this data is referring to a specific place on earth. Therefore, good and reliable geo-information is critical for the development of the SDG’s of a country.</p><p>Topographic maps describe the land that belongs to a country, its sovereign territory. But they are also used for orientation, for the defense of your country, as a time stamp of how your country looks like at a specific moment in time, and many other applications. Topographic maps are therefore an indispensable asset in an NSDI. They link thematic information of any kind to a specific location. It is this location that is the linking pin to many other sources of information.</p><p>However, the reality of today is that many developing countries lack any up-to-date topographic maps. They have to rely on old maps, often produced more than 40 years ago; there is no money or, more importantly, no expertise available to update these maps. In other cases, they rely on online mapping sources like Google Maps, OpenStreetMap, etc. These are good, but consistency in quality is an issue.</p><p>Some countries already have topographic maps, but these date back from colonial times, and were not updated ever since. Others produce specific map series but are depending on the availability of reliable source material, like aerial photos and satellite imagery, purchased by the government. Or in some cases they have to organize partnerships with other national institutions to be able to purchase the necessary photo’s or imagery. Regular maintenance of these maps is then often a real issue.</p><p>In general, every country has its own development stage, but when it comes to topographic mapping, it can be classified into 4 stages:</p><p>1. No topographic map available</p><p>2. Out of date analogue topographic map available</p><p>3. Digital, but out of date topographic map available</p><p>4. Digital and recent topographic map available</p><p>This paper describes these different stages of official map production that exist in countries around the world, each stage with its own characteristics, timeframe, roadmap and needs. It is not focusing on the technology but concentrates on the institutional aspects of topographic map production and what could be done to develop the production processes into sustainable work procedures.</p>

Quality Assessment of Globally Available Digital Elevation Model (DEM) for Mountainous Region

2021 ◽  
Vol 5 (1) ◽  
pp. 11-21
Author(s):  
Sangay Gyeltshen ◽  
Krisha Kumar Subedi ◽  
Laylo Zaridinova Kamoliddinovna ◽  
Jigme Tenzin
Keyword(s):  
Digital Elevation Model ◽  
Vertical Displacement ◽  
Satellite System ◽  
Topographic Map ◽  
Alos Palsar ◽  
Aster Gdem ◽  
Digital Elevation ◽  
The Government ◽  
Elevation Model ◽  
The Individual

The study assessed the accuracies of globally available Digital Elevation Models (DEM’s) i.e., SRTM v3, ASTER GDEM v2 and ALOS PALSAR DEM with respect to Topo-DEM derived from topographic map of 5m contour interval. 100 ground control points of the elevation data were collected with the help of kinematic hand held GNSS (Global Navigation Satellite System), randomly distributed over the study area. The widely used RMSE statistic, NCC correlation and sub-pixel-based approach were applied to evaluate the erroneous, correlation, horizontal and vertical displacement in terms of pixels for the individual Digital Elevation Model. Following these evaluations, SRTM DEM was found to be highly accurate in terms of RMSE and displacement compared to other DEMs. This study is intended to provide the researchers, GIS specialists and the government agencies dealing with remote sensing and GIS, a basic clue on accuracy of the DEMs so that the best model can be selected for application on various purposes of the similar region.

scholarly journals Glacier geometry and elevation changes on Svalbard (1936–90): a baseline dataset

2007 ◽  
Vol 46 ◽  
pp. 106-116 ◽  
Author(s):  
C. Nuth ◽  
J. Kohler ◽  
H.F. Aas ◽  
O. Brandt ◽  
J.O. Hagen
Keyword(s):  
Aerial Survey ◽  
Aerial Photographs ◽  
Time Interval ◽  
Topographic Map ◽  
Elevation Change ◽  
Regional Variability ◽  
Random Components ◽  
Elevation Changes ◽  
Norwegian Polar Institute ◽  
Elevation Model

AbstractThis study uses older topographic maps made from high-oblique aerial photographs for glacier elevation change studies. We compare the 1936/38 topographic map series of Svalbard (Norwegian Polar Institute) to a modern digital elevation model from 1990. Both systematic and random components of elevation error are examined by analyzing non-glacier elevation difference points. The 1936/38 photographic aerial survey is examined to identify areas with poor data coverage over glaciers. Elevation changes are analyzed for seven regions in Svalbard (~5000 km2), where significant thinning was found at glacier fronts, and elevation increases in the upper parts of the accumulation areas. All regions experience volume losses and negative geodetic balances, although regional variability exists relating to both climate and topography. Many surges are apparent within the elevation change maps. Estimated volume change for the regions is –1.59±0.07km3 a–1 (ice equivalent) for a geodetic annual balance of –0.30ma–1w.e., and the glaciated area has decreased by 16% in the 54 year time interval. The 1936–90 data are compared to modern elevation change estimates in the southern regions, to show that the rate of thinning has increased dramatically since 1990.

scholarly journals Teaching of geographical space relations for cartography – <i>Academic Outdoor Station in Poznan (Poland)</i>

2019 ◽  
Vol 1 ◽  
pp. 1-1
Author(s):  
Beata Medynska-Gulij ◽  
Maciej Smaczynski ◽  
Dariusz Lorek ◽  
Łukasz Halik ◽  
Łukasz Wielebski ◽  
...  
Keyword(s):  
Augmented Reality ◽  
Spatial Relations ◽  
Topographic Map ◽  
University Campus ◽  
Optical Illusions ◽  
The North ◽  
Single Plate ◽  
Contour Lines ◽  
Virtual And Augmented Reality ◽  
The University

<p><strong>Abstract.</strong> The identification of geographical phenomena and relations between them are most frequently visualized, analyzed and interpreted indoor by the display screen. The difficulties with capturing basic spatial relations significant in the process of teaching cartography become the main problem. The objective of teachers from the Department of Cartography and Geomatics was to enrich typical classes carried out in computer rooms by adding the outdoor academic classes that would encourage students to observe those relations directly in the field. In October 2018 the outdoor station of the area of 15&amp;thinsp;&amp;times;&amp;thinsp;20&amp;thinsp;m by the university campus next to <i>Collegium Geographicum</i> was handed over to the disposal of students. The projects of the elements of the station were created on the basis of the lecturers experience as a part of subjects on the following courses: topographical cartography, survey techniques, cartographic design, virtual and augmented reality in cartography, geovisualization and geomatics. Sets of several constructions that can be used either separately, as tools for explaining specific principles or together, as instruments for teaching subsequent measurement, location and visualization relations occurring in cartography and geomatics, were placed on the premises of the station.</p><p>In order to study historical ways of marking borders, the erratic, a replica of the boundary stone from 1653 with the triangle engraved in the place in which three countries connect, was placed in the field. Contemporary ways of the stabilization of the border points and points of the grid reference are farther located. The point marked on the metal horizontal plate, on the spot in which the meridian and the parallel of latitude cross, inform about multiple ways of recording the exact location in space. The values of coordinates were calculated for that point and engraved on the board in several nation and global reference systems. Students, standing on other three plates with the points marked where meridians cross parallels of latitude, create basic elements of the grid of latitude and longitude of 0.2''.</p><p>On a single plate three directions of the north, i.e. the geographic, topographic and magnetic one, are visible. One of the meridians marks the line of analemmatic sundial to 12:00&amp;thinsp;a.m. and the student standing on the area of the specific month becomes a gnomon whose shadow indicates the hour of the local meridian. Two surveyor's levelling rods with two values differing by approximately 16&amp;thinsp;cm demonstrate different values of contour lines on topographic maps worked out in Poland. Properly oriented topographic table shows the same fragment of space in four ways: on the classic, north-oriented topographic map, on the orthophotomap at 1&amp;thinsp;:&amp;thinsp;10&amp;thinsp;000 scale, on the simplified visualization of a few layers from the national topographic base at enlarged 1&amp;thinsp;:&amp;thinsp;2&amp;thinsp;000 scale and on the 3D printout on which the height of buildings was determined from the attribute table.</p><p>Authors of the Academic Outdoor Station in Poznan prepared for the conference guests the multimedia presentation with the explanations of the aforementioned constructions and other elements, i.e. the wall of cartographic visualizations with perspective and optical illusions presented on 2D boards, virtual and augmented reality table, triangular signal, and others. We hope to receive feedback from cartographers and hear some ideas concerning new constructions for our station.</p>

scholarly journals THE DESIGN AND PRODUCT OF NATIONAL 1:1000000 CARTOGRAPHIC DATA OF TOPOGRAPHIC MAP

2016 ◽  
Vol XLI-B2 ◽  
pp. 245-249
Author(s):  
Guizhi Wang
Keyword(s):  
Line Graph ◽  
Topographic Map ◽  
Dynamic Update ◽  
Structure Database ◽  
Database Structure ◽  
Digital Elevation ◽  
Mapping Technology ◽  
Elevation Model ◽  
Digital Elevation Model Data ◽  
Information Database

National administration of surveying, mapping and geoinformation started to launch the project of national fundamental geographic information database dynamic update in 2012. Among them, the 1:50000 database was updated once a year, furthermore the 1:250000 database was downsized and linkage-updated on the basis. In 2014, using the latest achievements of 1:250000 database, comprehensively update the 1:1000000 digital line graph database. At the same time, generate cartographic data of topographic map and digital elevation model data. This article mainly introduce national 1:1000000 cartographic data of topographic map, include feature content, database structure, Database-driven Mapping technology, workflow and so on.

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