Prediction of soil salinity risk by digital terrain modeling in the Canadian prairies

2000 ◽  
Vol 80 (3) ◽  
pp. 455-463 ◽  
Author(s):  
I. V. Florinsky ◽  
R. G. Eilers ◽  
G. W. Lelyk
Keyword(s):  
Soil Salinity ◽  
Risk Index ◽  
Small Scale ◽  
Canadian Prairies ◽  
Digital Terrain ◽  
Terrain Models ◽  
Digital Elevation ◽  
Soil Salinisation ◽  
Elevation Model ◽  
Digital Terrain Modeling

Soil salinisation is a typical problem for the Canadian prairies. At macro-topographic scale, build-up of salts occurs in depressions. However, this relationship is not displayed on existing small-scale maps of soil salinity. To improve these maps, one can use a concept of accumulation, transition and dissipation zones of the landsurface. The concept allows one to reveal depressions (topographically expressed accumulation zones) using digital models of horizontal and vertical curvatures, or accumulation and mean curvatures derived from a digital elevation model. We applied the concept of accumulation, transition and dissipation zones to improve an existing small-scale map of the salinity risk index for the prairies and adjacent areas. A comparison of the old and the improved maps demonstrated that once data on depressions have been taken into account, areas marked by salinity risk decreased significantly. We suggest that the method used may prevent an overestimation in predictions of soil cover degradation due to salinisation. The method used can also reveal saline areas linked with discharges of saline aquifers. This is because sites marked by high discharges of groundwater usually relate to sites of intensive fracturing of geological materials, which are closely associated with topographically expressed accumulation zones. Key words: Digital terrain models, topography, soil salinisation, mapping

scholarly journals The possible use of ancient tower tombs as watchtowers in Syro-Mesopotamia

2015 ◽  
Vol II-5/W3 ◽  
pp. 287-293 ◽  
Author(s):  
M. Silver ◽  
M. Törmä ◽  
K. Silver ◽  
J. Okkonen ◽  
M. Nuñez
Keyword(s):  
Srtm Dem ◽  
Model Data ◽  
Greco Roman ◽  
Digital Terrain ◽  
Terrain Models ◽  
Digital Elevation ◽  
Previous Decade ◽  
Euphrates Valley ◽  
Elevation Model ◽  
Digital Elevation Model Data

Traditionally polygonal tower tombs dating from the Greco-Roman era, especially found in the area of Syro-Mesopotamia, have only been treated as funerary structures without discussion of their other possible purposes. In this paper we wish to inquire whether they had other functions as well. The most famous examples of these types of tombs are situated in Palmyra in Syria. They are built of limestone, follow a square layout, and some exceed the height of 20 m. Similar structures are found in the Euphrates valley of Syria. The Finnish project SYGIS that worked in the neighbourhood of the Euphrates and Palmyra during the previous decade studied some of the structures in the region. As far as the tower tombs are concerned, our research suggests that new structural, topographical and spatial aspects can be raised, and GIS (Geographic Information Systems) can be applied for analysing their properties for visibility. The tendency to locate tower tombs along roads and the entrance areas of a city as well as at a mountain edge seems to indicate that the tombs may have had observational functions serving as watch towers. The aspects of the location in terrains are emphasized in the present study, and digital terrain models were utilized using SRTM DEM (Digital Elevation Model) data for carrying out viewshed analyses in order to survey the observational qualities of the towers in Palmyra, on Halabiya, on Jebel Bishri in Syria and Hatra in Iraq.

Caracteristici morfometrice ale reliefului bazinului râului Bucovăț

2019 ◽  
Author(s):  
Andrei Craciun ◽  
◽  
Iurie Bejan ◽  
Keyword(s):  
Digital Elevation Model ◽  
Input Data ◽  
General Information ◽  
Virtual Space ◽  
Digital Terrain ◽  
Digital Elevation ◽  
Elevation Model ◽  
Digital Terrain Modeling ◽  
Geomorphometric Parameters ◽  
Topographical Attributes

In the sense of digital terrain modeling, there is a set of techniques for obtaining a Digital Elevation Model (DEM). But, as expected, modeling the terrestrial surface, its representation in a virtual space, involves certain problems that are related to the surface specificity itself and our way of measuring it. Numerical altitude models, once performed, find their usefulness as input data for derivation of some topographical attributes of geomorphometric parameters, morphometric variables or general information about the land respectively.

scholarly journals DETERMINING THE SUITABILITY OF DIFFERENT DIGITAL ELEVATION MODELS AND SATELLITE IMAGES FOR FANCY MAPS. AN EXAMPLE OF CYPRUS

2016 ◽  
Vol XLI-B4 ◽  
pp. 591-597
Author(s):  
J. Drachal ◽  
A. K. Kawel
Keyword(s):  
Small Area ◽  
Satellite Images ◽  
Digital Elevation Models ◽  
Test Area ◽  
Landsat 8 ◽  
Digital Terrain Models ◽  
Digital Terrain ◽  
Terrain Models ◽  
Digital Elevation ◽  
Shaded Relief

The article describes the possibility of developing an overall map of the selected area on the basis of publicly available data. Such a map would take the form designed by the author with the colors that meets his expectations and a content, which he considers to be appropriate. Among the data available it was considered the use of satellite images of the terrain in real colors and, in the form of shaded relief, digital terrain models with different resolutions of the terrain mesh. Specifically the considered data were: MODIS, Landsat 8, GTOPO-30, SRTM-30, SRTM-1, SRTM-3, ASTER. For the test area the island of Cyprus was chosen because of the importance in tourism, a relatively small area and a clearly defined boundary. In the paper there are shown and discussed various options of the Cyprus terrain image obtained synthetically from variants of Modis, Landsat and digital elevation models of different resolutions.

scholarly journals Transformations of Landscape Topography of the Bełchatów Coal Mine (Central Poland) and the Surrounding Area Based on DEM Analysis

2019 ◽  
Vol 8 (9) ◽  
pp. 403 ◽  
Author(s):  
Marcin Jaskulski ◽  
Tomasz Nowak
Keyword(s):  
Power Plant ◽  
Brown Coal ◽  
Open Pit ◽  
Central Poland ◽  
German Army ◽  
Terrain Models ◽  
Digital Elevation ◽  
Dem Analysis ◽  
Elevation Model ◽  
Topographical Maps

The authors analyze topography changes related to the construction and operation of the Bełchatów Brown Coal Open Mine and Power Plant, one of Europe’s larger open-pit mines, situated in central Poland. In order to achieve this, a DEM (Digital Elevation Model) is prepared, based on archival materials from the pre-investment period. Source materials include German topographical maps, issued in 1944 by the Supreme High Command of the German Army (Oberkommando des Heeres/Generalstab). The second model of the same area is prepared based on DEM data included in the Topographical Database available by CODGiK (Main Centre of Geodetic and Cartographic Documentation). The preparation of two terrain models from different periods make it possible to evaluate the changes in the morphometry. Both models are compared using ArcGIS (ESRI) tools. The comparative analysis of the models allows for observing topography changes resulting from anthropogenic transformations related to the construction of the Brown Coal Open Mine Bełchatów and Power Plant complex.

The Coupling Relationship between Forest Vegetation and Terrain of Daliuta Mine

2014 ◽  
Vol 641-642 ◽  
pp. 1191-1194 ◽  
Author(s):  
Dong Wen Liu ◽  
Zhi Yong Qiao ◽  
Ting Ting Wei ◽  
Shu Jiang ◽  
Ya Kai Chen ◽  
...  
Keyword(s):  
Digital Terrain Model ◽  
Vegetation Coverage ◽  
Terrain Model ◽  
Digital Terrain ◽  
Digital Elevation ◽  
Object Use ◽  
Trend Data ◽  
Elevation Model ◽  
Digital Elevation Model Data ◽  
Evolution Trend

Taking Daliuta mine as research object, use its 2002, 2011 two same period Landsat TM/ ETM and remote sensing image as the data source, use pixel dichotomy to get its vegetation coverage evolution trend data; Use DEM digital elevation model data in the region to generate digital terrain model based on ArcGIS, and make overlay analysis with the vegetation coverage evolution trend data to study the relationship between the vegetation coverage and terrain factor of the mine area. The results showed that: From 2002 to 2011, the vegetation coverage evolution trend of Daliuta mining mainly moderate improvement and significantly improvement, and concentrated in middle altitude, low slope, sunny area.

scholarly journals Heterogeneidade da Rugosidade em Terrenos Complexos e Implicações para o Aproveitamento Eólico (Heterogeneity of Roughness in Complex Terrains and Implications for Wind Power)

2016 ◽  
Vol 9 (2) ◽  
pp. 546
Author(s):  
Thiago Lobão Cordeiro ◽  
Arcilan Trevenzoli Assireu ◽  
Ramon Moraes Freitas ◽  
Nandamudi Lankalapalli Vijaykumar ◽  
Reinaldo Roberto Rosa
Keyword(s):  
Wind Power ◽  
Roughness Length ◽  
Small Scale ◽  
Measuring Point ◽  
Wind Pattern ◽  
Displacement Height ◽  
Digital Elevation ◽  
Wind Profiles ◽  
Elevation Model ◽  
Plane Displacement

A demanda para a produção de energia renovável e de baixo impacto ambiental cresce a cada ano e, com isso, há também o aumento do interesse em turbinas eólicas de pequena escala a serem instaladas em relevos complexos que inclui áreas onde montanhas afetam o padrão de vento, como em grandes sistemas aquáticos localizados em regiões de planaltos. A influência da complexidade do relevo e da intensidade de turbulência foi investigada pela aplicação do método de Análise por Padrões de Gradientes em um modelo digital de elevação e uma série de dados histórica da direção e velocidade do vento. Os resultados indicaram que os padrões de fluxos são extremamente complexos e variam significativamente dependendo da direção do fluxo em sentido contrário. Esta variabilidade também torna difícil definir um plano zero de deslocamento ou um comprimento de rugosidade para um determinado ponto de medição, o que compromete a utilização do modelo de extrapolação vertical do vento baseado no coeficiente de rugosidade fixo.      ABSTRACT As the demand for environmentally friendly energy production grows, there is also an increased interest in small scale wind turbines located in more complex relief that includes areas where mountains affect the wind pattern, as in large inland aquatic system localized close to hills. Influence of complex relief on the turbulence intensity was investigated by means of time series of the wind direction and speed and digital elevation model. The results indicated that the flow patterns are highly complex and vary significantly depending on the direction of the oncoming flow. This variability also makes it difficult to define a general zero plane displacement height or a roughness length for a certain measuring point. The resulting consequence for the usual one-dimensional wind profiles models are then pointed out. Keywords: GPA. Roughness of the relief. Wind power.   

scholarly journals EVALUATING ERROR OF LIDAR DERIVED DEM INTERPOLATION FOR VEGETATION AREA

2016 ◽  
Vol XLII-4/W1 ◽  
pp. 141-150 ◽  
Author(s):  
Z. Ismail ◽  
M. F. Abdul Khanan ◽  
F. Z. Omar ◽  
M. Z. Abdul Rahman ◽  
M. R. Mohd Salleh
Keyword(s):  
Spatial Resolution ◽  
Accuracy Assessment ◽  
Digital Terrain Model ◽  
Geographical Information ◽  
Interpolation Methods ◽  
Terrain Model ◽  
Digital Terrain ◽  
Digital Elevation ◽  
Elevation Model ◽  
Slope Class

Light Detection and Ranging or LiDAR data is a data source for deriving digital terrain model while Digital Elevation Model or DEM is usable within Geographical Information System or GIS. The aim of this study is to evaluate the accuracy of LiDAR derived DEM generated based on different interpolation methods and slope classes. Initially, the study area is divided into three slope classes: (a) slope class one (0° – 5°), (b) slope class two (6° – 10°) and (c) slope class three (11° – 15°). Secondly, each slope class is tested using three distinctive interpolation methods: (a) Kriging, (b) Inverse Distance Weighting (IDW) and (c) Spline. Next, accuracy assessment is done based on field survey tachymetry data. The finding reveals that the overall Root Mean Square Error or RMSE for Kriging provided the lowest value of 0.727 m for both 0.5 m and 1 m spatial resolutions of oil palm area, followed by Spline with values of 0.734 m for 0.5 m spatial resolution and 0.747 m for spatial resolution of 1 m. Concurrently, IDW provided the highest RMSE value of 0.784 m for both spatial resolutions of 0.5 and 1 m. For rubber area, Spline provided the lowest RMSE value of 0.746 m for 0.5 m spatial resolution and 0.760 m for 1 m spatial resolution. The highest value of RMSE for rubber area is IDW with the value of 1.061 m for both spatial resolutions. Finally, Kriging gave the RMSE value of 0.790m for both spatial resolutions.

scholarly journals Evaluating digital terrain indices for soil wetness mapping – a Swedish case study

2014 ◽  
Vol 18 (9) ◽  
pp. 3623-3634 ◽  
Author(s):  
A. M. Ågren ◽  
W. Lidberg ◽  
M. Strömgren ◽  
J. Ogilvie ◽  
P. A. Arp
Keyword(s):  
Surface Flow ◽  
Topographic Wetness Index ◽  
Water Index ◽  
Digital Terrain ◽  
Digital Elevation ◽  
Soil Disturbances ◽  
Soil Wetness ◽  
Elevation Model ◽  
Terrain Indices

Abstract. Trafficking wet soils within and near stream and lake buffers can cause soil disturbances, i.e. rutting and compaction. This – in turn – can lead to increased surface flow, thereby facilitating the leaking of unwanted substances into downstream environments. Wet soils in mires, near streams and lakes have particularly low bearing capacity and are therefore more susceptible to rutting. It is therefore important to model and map the extent of these areas and associated wetness variations. This can now be done with adequate reliability using a high-resolution digital elevation model (DEM). In this article, we report on several digital terrain indices to predict soil wetness by wet-area locations. We varied the resolution of these indices to test what scale produces the best possible wet-areas mapping conformance. We found that topographic wetness index (TWI) and the newly developed cartographic depth-to-water index (DTW) were the best soil wetness predictors. While the TWI derivations were sensitive to scale, the DTW derivations were not and were therefore numerically robust. Since the DTW derivations vary by the area threshold for setting stream flow initiation, we found that the optimal threshold values for permanently wet areas varied by landform within the Krycklan watershed, e.g. 1–2 ha for till-derived landforms versus 8–16 ha for a coarse-textured alluvial floodplain.

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