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 Geomorphometry of drainage basins: a global view from the Shuttle Radar Topography Mission

2011 ◽  
Vol 8 (1) ◽  
pp. 1929-1949
Author(s):  
P. L. Guth
Keyword(s):  
Digital Elevation Model ◽  
Shuttle Radar Topography Mission ◽  
Global Distribution ◽  
Drainage Basins ◽  
Global View ◽  
Digital Elevation ◽  
Elevation Model ◽  
Geomorphometric Parameters

Abstract. A suite of 42 geomorphometric parameters for each of 26 272 drainage basins larger than 100 km2 from the Hydrosheds Shuttle Radar Topography digital elevation model shows the global distribution of Strahler order for streams and drainage basins; the largest basins are order 9. Many common parameters depend both on the size of the basin, and the scale of the digital elevation model used for the computations. These drainage basins display the typical longitudinal stream profiles, but the major basins tend to be more convex than the smaller basins.

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 Digital terrain analysis of the Haute-Mentue catchment an scale effect for hydrological modelling with TOPMODEL

2000 ◽  
Vol 4 (2) ◽  
pp. 225-237 ◽  
Author(s):  
C. Higy ◽  
A. Musy
Keyword(s):  
Digital Elevation Model ◽  
Scale Effects ◽  
Digital Terrain Model ◽  
Hydrological Modelling ◽  
Terrain Analysis ◽  
Topographic Index ◽  
Terrain Model ◽  
Digital Terrain ◽  
Digital Elevation ◽  
Elevation Model

Abstract. It is widely recognised that topography plays an important role in the generation of runoff. The scale of a digital elevation model has been found to have some impacts on the results of hydrological modelling in several studies. In particular it has been shown that the representation of the statistical distribution of the topographic index used by TOPMODEL is sensitive to the scale of the digital terrain model. The objectives of this study are to develop an analysis of the topography and scale effects for the Haute-Mentue catchment and to test the role of different spatial resolution on parameter calibration. The major result is that the spatial scale is important for the parameter values, but not determinant for the modelling results if a pertinent methodology is adopted for the determination of digital watershed representation. Keywords: digital elevation model, topographic index, scale problems, TOPMODEL

scholarly journals Impacts of spatial data resolution on simulated discharge, a case study of Xitiaoxi catchment in South China

2009 ◽  
Vol 21 ◽  
pp. 131-137 ◽  
Author(s):  
G. J. Zhao ◽  
G. Hörmann ◽  
N. Fohrer ◽  
J. F. Gao
Keyword(s):  
Land Use ◽  
Cell Size ◽  
Digital Elevation Model ◽  
South China ◽  
Spatial Data ◽  
Input Data ◽  
Grid Size ◽  
Digital Elevation ◽  
Data Resolution ◽  
Elevation Model

Abstract. In this paper we analyse the effects of different spatial input data resolution on water balance simulation using a simple distributed hydrological model: PCR-XAJ model. A data set consisting of land use and digital elevation model at 25 m resolution of Xitiaoxi catchment in South China is used for investigation. The model was first calibrated and validated at 50 m cell size, thereafter an aggregation of the digital elevation model (DEM) and land use maps at 100 m, 200 m, 300 m, 500 m and 1 km are applied to evaluate the effects of spatial data resolution on simulated discharge. The simulation results at a grid size of 50 m show a good correlation between measured and simulated daily flows at Hengtangcun station with Nash-Suttcliffe efficiency larger than 0.75 for both calibration and validation periods. In contrast, the model performs slightly worse at Fanjiacun station. The increasing grid size affects the characteristics of the slope and land use aggregation and causes important information loss. The aggregation of input data does not lead to significant errors up to a grid of 1 km. Model efficiencies decrease slightly with cell size increasing, and more significantly up to the grid size of 1 km.

scholarly journals Applied spatial analytic tools in orchards with special regard to agro-ecology

2011 ◽  
Vol 17 (1-2) ◽  
Author(s):  
T. Fórián ◽  
A. Nagy ◽  
J. Tamás ◽  
Z. Szabó ◽  
M. Soltész ◽  
...  
Keyword(s):  
Digital Elevation Model ◽  
Digital Terrain Model ◽  
Analytical Techniques ◽  
Soil Surface ◽  
Terrain Model ◽  
Digital Terrain ◽  
Contour Lines ◽  
Digital Elevation ◽  
Elevation Model ◽  
Fruit Orchards

Our investigation was carried out in several orchards in Hungary. This study reviews applicability of the different spatial analytical techniques in orchard especially models based on surface relief, such as digital elevation model, digital terrain model, slope and aspect maps. In recent time, the generation of digital elevation model has become a popular examination method. However, the elevation models generated from contour lines or elevation points could be applied to evaluate agro- ecological potential of fruit orchards to some extent. The highest deficiency of these models is the fact that these show the altitude of soil surface only and do not demonstrate landmarks on the surface. Consequently, the calculation of the radiation value results data relating to soil surface. The terrain model generated and applied by our team demonstrates fine surface texture and the landmarks in the orchard, so it is suitable for further examination.

STUDY OF THE LANDSLIDE MORPHOLOGY BASED ON GNSS DATA AND AIRBORNE SOUNDING (ON THE EXAMPLE OF A SECTION OF THE PROTVA RIVER VALLEY)

2018 ◽  
Vol 12 (5-6) ◽  
pp. 50-57 ◽  
Author(s):  
I. S. Voskresensky ◽  
A. A. Suchilin ◽  
L. A. Ushakova ◽  
V. M. Shaforostov ◽  
A. L. Entin ◽  
...  
Keyword(s):  
Digital Elevation Model ◽  
Geodetic Network ◽  
Aerial Survey ◽  
River Valley ◽  
Ease Of Use ◽  
Digital Elevation ◽  
Loose Deposits ◽  
Positioning Method ◽  
Landslide Body ◽  
Elevation Model

To use unmanned aerial vehicles (UAVs) for obtaining digital elevation models (DEM) and digital terrain models (DTM) is currently actively practiced in scientific and practical purposes. This technology has many advantages: efficiency, ease of use, and the possibility of application on relatively small area. This allows us to perform qualitative and quantitative studies of the progress of dangerous relief-forming processes and to assess their consequences quickly. In this paper, we describe the process of obtaining a digital elevation model (DEM) of the relief of the slope located on the bank of the Protva River (Satino training site of the Faculty of Geography, Lomonosov Moscow State University). To obtain the digital elevation model, we created a temporary geodetic network. The coordinates of the points were measured by the satellite positioning method using a highprecision mobile complex. The aerial survey was carried out using an unmanned aerial vehicle from a low altitude (about 40–45 m). The processing of survey materials was performed via automatic photogrammetry (Structure-from-Motion method), and the digital elevation model of the landslide surface on the Protva River valley section was created. Remote sensing was supplemented by studying archival materials of aerial photography, as well as field survey conducted immediately after the landslide. The total amount of research results made it possible to establish the causes and character of the landslide process on the study site. According to the geomorphological conditions of formation, the landslide refers to a variety of landslideslides, which are formed when water is saturated with loose deposits. The landslide body was formed with the "collapse" of the blocks of turf and deluvial loams and their "destruction" as they shifted and accumulated at the foot of the slope.

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