scholarly journals Evaluation of the wind erosion risks in GIS

2008 ◽  
Vol 2 (No. 1) ◽  
pp. 10-14
Author(s):  
J. Podhrázská ◽  
I. Novotný
Keyword(s):  
Wind Erosion ◽  
Agricultural Land ◽  
Meteorological Data ◽  
Digital Terrain Model ◽  
Climatic Conditions ◽  
Topographic Maps ◽  
Terrain Model ◽  
Digital Terrain ◽  
Potential Risks ◽  
Information Database

The paper refers to the possibilities of the evaluation of the wind erosion risks by using a model created in GIS. The model exploits the pedological information database for determining the potential risks of soils by wind erosion. The following data are the database of the agricultural land use, meteorological data and the topographic maps for determining the direction of wind and climatic conditions. Using the data transferred to the graphic form, it is possible to create the digital terrain model and to regionalise the meteorological data. Consequently, the wind barriers are localised in the landscape and it is possible to create the zone of efficiency around each barrier (protecting the land from the erosive effects of the wind) according to the characteristics of their height and density.

scholarly journals Areal melt and discharge modelling of Storglaciären, Sweden

1997 ◽  
Vol 24 ◽  
pp. 211-216 ◽  
Author(s):  
Regine Hock ◽  
Christian Noetzli
Keyword(s):  
Meteorological Data ◽  
Grid Point ◽  
Digital Terrain Model ◽  
Turbulent Fluxes ◽  
Heat Fluxes ◽  
Balance Model ◽  
Turbulent Heat ◽  
Terrain Model ◽  
Digital Terrain ◽  
One Year

A grid-based glacier melt-and-discharge model was applied to Storglaciären, a small valley glacier (3 km2) in northern Sweden, for the melt seasons of 1993 and 1994. The energy available for melt was estimated from a surface energy-balance model using meteorological data collected by automatic weather stations on the glacier. Net radiation and the turbulent heat fluxes were calculated hourly for every grid point of a 30 m resolution digital terrain model, using the measurements of temperature, humidity, wind speed and radiative fluxes on the glacier. Two different bulk approaches were used to calculate the turbulent fluxes and compared with respect to their impact on discharge simulations. Discharge of Storglaciären was simulated from calculated meltwater production and precipitation by three parallel linear reservoirs corresponding to the different storage properties of firn, snow and ice. The performance of the model was validated by comparing simulated discharge to measured discharge at the glacier snout. Depending on which parameterization of the turbulent fluxes was used, the timing and magnitude of simulated discharge was in good agreement with observed discharge, or simulated discharge was considerably underestimated in one year.

The Conception of the Net Weather Station for Measuring the Microclimate of the Forest

2017 ◽  
Author(s):  
Paweł Szymanski ◽  
Michał Brach ◽  
Marcin Szymanski ◽  
Michał Smieja ◽  
Wojciech O>ga
Keyword(s):  
Meteorological Data ◽  
Digital Terrain Model ◽  
Main Idea ◽  
Strongly Correlated ◽  
Weather Station ◽  
Current Time ◽  
Terrain Model ◽  
Digital Terrain ◽  
Grid Points ◽  
Sd Card

The project of meteorological station is designed to monitor the state of the weather on the selected (forest areas) as well as the colleting the data to analyze the dynamic of the changes weather parameters. The main idea presented in this paper, base on assumption that single weather station can be used as a part of net. The simultaneous and continuous measurement of many parameters such as temperature, pressure, humidity and sunlight located at grid points could work out finaly the weather map combined with the digital terrain model. The modern electronic make possible flexible connecting indywidual stations in subsytems and exchange of huge amount of inforamtion leading to build base knowledge. In the first part of the article it is presented the conception of the information system. In the next part there are are outlined the results of works with the prototype of the measure mode. Dedicated to applications in forestry prototype of device, can be used to measure temperature, pressure, humidity and sunlight. The additional features of the device are the possibility of writing data on micro SD card, supplemented with current time, day, and year. The design and research is a pilot, before the creation of a regular grid of sample plots with the use of many such devices. The objective is to gather accurate meteorological data from the interior of the forest-based geostatistical analysis, necessary for breeding purposes. Because of their design frames weather, it can be installed on most trees. Presented prototype of basic station used in the concept of measuring net, generates data from the sensors, which are strongly correlated with the compared professional station.

scholarly journals Areal melt and discharge modelling of Storglaciären, Sweden

1997 ◽  
Vol 24 ◽  
pp. 211-216 ◽  
Author(s):  
Regine Hock ◽  
Christian Noetzli
Keyword(s):  
Meteorological Data ◽  
Grid Point ◽  
Digital Terrain Model ◽  
Turbulent Fluxes ◽  
Heat Fluxes ◽  
Balance Model ◽  
Turbulent Heat ◽  
Terrain Model ◽  
Digital Terrain ◽  
One Year

A grid-based glacier melt-and-discharge model was applied to Storglaciären, a small valley glacier (3 km2) in northern Sweden, for the melt seasons of 1993 and 1994. The energy available for melt was estimated from a surface energy-balance model using meteorological data collected by automatic weather stations on the glacier. Net radiation and the turbulent heat fluxes were calculated hourly for every grid point of a 30 m resolution digital terrain model, using the measurements of temperature, humidity, wind speed and radiative fluxes on the glacier. Two different bulk approaches were used to calculate the turbulent fluxes and compared with respect to their impact on discharge simulations. Discharge of Storglaciären was simulated from calculated meltwater production and precipitation by three parallel linear reservoirs corresponding to the different storage properties of firn, snow and ice. The performance of the model was validated by comparing simulated discharge to measured discharge at the glacier snout. Depending on which parameterization of the turbulent fluxes was used, the timing and magnitude of simulated discharge was in good agreement with observed discharge, or simulated discharge was considerably underestimated in one year.

scholarly journals THE USE OF MULTIPLE DATA SOURCES IN THE PROCESS OF TOPOGRAPHIC MAPS UPDATING

2016 ◽  
Vol XLI-B4 ◽  
pp. 19-24
Author(s):  
A. Cantemir ◽  
A. Visan ◽  
N. Parvulescu ◽  
M. Dogaru
Keyword(s):  
Digital Terrain Model ◽  
Data Sources ◽  
Topographic Maps ◽  
Stream Network ◽  
Coverage Area ◽  
Terrain Model ◽  
Digital Terrain ◽  
Multiple Data ◽  
Good Spatial Resolution ◽  
Satellite Missions

The methods used in the process of updating maps have evolved and become more complex, especially upon the development of the digital technology. At the same time, the development of technology has led to an abundance of available data that can be used in the updating process. The data sources came in a great variety of forms and formats from different acquisition sensors. Satellite images provided by certain satellite missions are now available on space agencies portals. Images stored in archives of satellite missions such us Sentinel, Landsat and other can be downloaded free of charge.The main advantages are represented by the large coverage area and rather good spatial resolution that enables the use of these images for the map updating at an appropriate scale. In our study we focused our research of these images on 1: 50.000 scale map. DEM that are globally available could represent an appropriate input for watershed delineation and stream network generation, that can be used as support for hydrography thematic layer update. If, in addition to remote sensing aerial photogrametry and LiDAR data are ussed, the accuracy of data sources is enhanced. Ortophotoimages and Digital Terrain Models are the main products that can be used for feature extraction and update. On the other side, the use of georeferenced analogical basemaps represent a significant addition to the process. Concerning the thematic maps, the classic representation of the terrain by contour lines derived from DTM, remains the best method of surfacing the earth on a map, nevertheless the correlation with other layers such as Hidrography are mandatory. In the context of the current national coverage of the Digital Terrain Model, one of the main concerns of the National Center of Cartography, through the Cartography and Photogrammetry Department, is represented by the exploitation of the available data in order to update the layers of the Topographic Reference Map 1:5000, known as TOPRO5 and at the same time, through the generalization and additional data sources of the Romanian 1:50 000 scale map. This paper also investigates the general perspective of DTM automatic use derived products in the process of updating the topographic maps.

scholarly journals THE USE OF MULTIPLE DATA SOURCES IN THE PROCESS OF TOPOGRAPHIC MAPS UPDATING

2016 ◽  
Vol XLI-B4 ◽  
pp. 19-24 ◽  
Author(s):  
A. Cantemir ◽  
A. Visan ◽  
N. Parvulescu ◽  
M. Dogaru
Keyword(s):  
Digital Terrain Model ◽  
Data Sources ◽  
Topographic Maps ◽  
Stream Network ◽  
Coverage Area ◽  
Terrain Model ◽  
Digital Terrain ◽  
Multiple Data ◽  
Good Spatial Resolution ◽  
Satellite Missions

The methods used in the process of updating maps have evolved and become more complex, especially upon the development of the digital technology. At the same time, the development of technology has led to an abundance of available data that can be used in the updating process. The data sources came in a great variety of forms and formats from different acquisition sensors. Satellite images provided by certain satellite missions are now available on space agencies portals. Images stored in archives of satellite missions such us Sentinel, Landsat and other can be downloaded free of charge.The main advantages are represented by the large coverage area and rather good spatial resolution that enables the use of these images for the map updating at an appropriate scale. In our study we focused our research of these images on 1: 50.000 scale map. DEM that are globally available could represent an appropriate input for watershed delineation and stream network generation, that can be used as support for hydrography thematic layer update. If, in addition to remote sensing aerial photogrametry and LiDAR data are ussed, the accuracy of data sources is enhanced. Ortophotoimages and Digital Terrain Models are the main products that can be used for feature extraction and update. On the other side, the use of georeferenced analogical basemaps represent a significant addition to the process. Concerning the thematic maps, the classic representation of the terrain by contour lines derived from DTM, remains the best method of surfacing the earth on a map, nevertheless the correlation with other layers such as Hidrography are mandatory. In the context of the current national coverage of the Digital Terrain Model, one of the main concerns of the National Center of Cartography, through the Cartography and Photogrammetry Department, is represented by the exploitation of the available data in order to update the layers of the Topographic Reference Map 1:5000, known as TOPRO5 and at the same time, through the generalization and additional data sources of the Romanian 1:50 000 scale map. This paper also investigates the general perspective of DTM automatic use derived products in the process of updating the topographic maps.

scholarly journals FEATURES OF CONSTRUCTION OF DIGITAL RELIEF MODEL ACCORDING TO THE RESULTS OF GEODESIC SURVEYING LOCATIONS

2021 ◽  
Vol 1 (161) ◽  
pp. 104-108
Author(s):  
A. Batrakova ◽  
Y. Dorozhko ◽  
V. Yemets
Keyword(s):  
Surface Display ◽  
Digital Terrain Model ◽  
Topographic Maps ◽  
Surface Model ◽  
Terrain Model ◽  
Model Based ◽  
Digital Terrain ◽  
Geodetic Measurements ◽  
Geodetic Surveying

Topographic maps in digital and electronic forms are created on the basis of available paper topographic maps or on the basis of primary materials of geodetic surveys. Geodetic surveys are performed both by ground methods, without the use of photogrammetric materials, and on the basis of materials obtained as a result of ground phototheodolite or aerial photography. The construction of a digital terrain model is a multi-stage process, which consists of a significant number of interconnected operations performed at the stage of in-house processing of the results of geodetic measurements carried out during engineering and geodetic surveys. The quality of the final result of modeling depends on the quality of each stage of construction of a digital terrain model, so it is extremely important to pay attention to all technological processes of model construction. The digital relief model is considered as an ordered set of triangular faces constructed by the Delaunay algorithm. The main condition of this type of triangulation is that in the middle of the circle described around any triangle can not be the vertex of another triangle. Construction of a digital terrain model based on the results of geodetic surveying of the area in the general case can be divided into several stages. At the beginning, an automated construction of triangulation is performed on the basis of the results of geodetic measurements, which carry information about three-dimensional coordinates of survey points. Allotments adjust the display of horizontals. Regardless of the selected surface display style, the surface model is a grid of triangles. At the next stage of construction of the digital model of a relief carry out visual control of the created model and if necessary carry out editing of elements of a surface and change of position of edges of triangulation for change of position of horizontals. The last stage of building a digital terrain model based on the results of geodetic surveying of the area is the design of modeling results, the application of individual styles of reflection for individual areas of the surface and the creation of mountain strokes and signatures of horizontals.

scholarly journals Historical Terrain Changes Mapping Due to the Wind Erosion Degradation Processes

2016 ◽  
Vol 19 (1) ◽  
pp. 13-16
Author(s):  
Lenka Lackóová ◽  
Jana Kozlovsky Dufková
Keyword(s):  
Wind Erosion ◽  
Digital Terrain Model ◽  
Volumetric Method ◽  
Gps Receiver ◽  
Terrain Model ◽  
Erosion Processes ◽  
Digital Terrain ◽  
Data Loggers ◽  
Baseline Information ◽  
Physical Changes

Abstract In this paper we compare the Digital terrain model (DTM) created from contours extracted from the Base Map of Slovakia with the scale of 1 : 10000 from year 1970 and DTM derived from the points measured with the Trimble® R8 GPS receiver with TSC2 data loggers from 2013. The purpose of the provision of these DMTs is to create baseline information that we used in quantifying physical changes due to wind erosion processes in the terrain of selected field in 43 years, since 1970 to present 2013. The comparison of the DTMs was validated by the volumetric method during wind erosion event. The results achieved from the volumetric method show that in one erosion event, about 480 m3 of soil has been eroded and transported to another location. In DTM comparison (43 years) volume amount which was calculated by “3D analyst tool - terrain and TIN surface - Surface difference”, 31,228 m3 of eroded soil was accumulated in the area and 16,236 m3 was lost from the area. Totally 14,922 m3 (5.5 cm height across the whole field) was transported from outlying eroded fields.

scholarly journals The Effect of LiDAR Sampling Density on DTM Accuracy for Areas with Heavy Forest Cover

Forests ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 265
Author(s):  
Mihnea Cățeanu ◽  
Arcadie Ciubotaru
Keyword(s):  
Forest Cover ◽  
Initial Point ◽  
Ground Surface ◽  
Digital Terrain Model ◽  
Morphological Data ◽  
Sampling Density ◽  
Terrain Model ◽  
Digital Terrain ◽  
Point Density ◽  
The Impact

Laser scanning via LiDAR is a powerful technique for collecting data necessary for Digital Terrain Model (DTM) generation, even in densely forested areas. LiDAR observations located at the ground level can be separated from the initial point cloud and used as input for the generation of a Digital Terrain Model (DTM) via interpolation. This paper proposes a quantitative analysis of the accuracy of DTMs (and derived slope maps) obtained from LiDAR data and is focused on conditions common to most forestry activities (rough, steep terrain with forest cover). Three interpolation algorithms were tested: Inverse Distance Weighted (IDW), Natural Neighbour (NN) and Thin-Plate Spline (TPS). Research was mainly focused on the issue of point data density. To analyze its impact on the quality of ground surface modelling, the density of the filtered data set was artificially lowered (from 0.89 to 0.09 points/m2) by randomly removing point observations in 10% increments. This provides a comprehensive method of evaluating the impact of LiDAR ground point density on DTM accuracy. While the reduction of point density leads to a less accurate DTM in all cases (as expected), the exact pattern varies by algorithm. The accuracy of the LiDAR-derived DTMs is relatively good even when LiDAR sampling density is reduced to 0.40–0.50 points/m2 (50–60 % of the initial point density), as long as a suitable interpolation algorithm is used (as IDW proved to be less resilient to density reductions below approximately 0.60 points/m2). In the case of slope estimation, the pattern is relatively similar, except the difference in accuracy between IDW and the other two algorithms is even more pronounced than in the case of DTM accuracy. Based on this research, we conclude that LiDAR is an adequate method for collecting morphological data necessary for modelling the ground surface, even when the sampling density is significantly reduced.

scholarly journals DTM-based analysis of the spatial distribution of topolineaments

2020 ◽  
Vol 12 (1) ◽  
pp. 1185-1199
Author(s):  
Mirosław Kamiński
Keyword(s):  
Laser Scanning ◽  
Digital Terrain Model ◽  
Research Area ◽  
Tectonic Structures ◽  
Empirical Bayesian ◽  
Scanning Method ◽  
Empirical Bayesian Kriging ◽  
Terrain Model ◽  
Digital Terrain ◽  
Airborne Laser

AbstractThe research area is located on the boundary between two Paleozoic structural units: the Radom–Kraśnik Block and the Mazovian–Lublin Basin in the southeastern Poland. The tectonic structures are separated by the Ursynów–Kazimierz Dolny fault zone. The digital terrain model obtained by the ALS (Airborne Laser Scanning) method was used. Classification and filtration of an elevation point cloud were performed. Then, from the elevation points representing only surfaces, a digital terrain model was generated. The model was used to visually interpret the course of topolineaments and their automatic extraction from DTM. Two topolineament systems, trending NE–SW and NW–SE, were interpreted. Using the kernel density algorithm, topolineament density models were generated. Using the Empirical Bayesian Kriging, a thickness model of quaternary deposits was generated. A relationship was observed between the course of topolineaments and the distribution and thickness of Quaternary formations. The topolineaments were compared with fault directions marked on tectonic maps of the Paleozoic and Mesozoic. Data validation showed consistency between topolineaments and tectonic faults. The obtained results are encouraging for further research.

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