scholarly journals Evidence of Hierarchy in the Drainage Basins Size Distribution of Greece Derived from ASTER GDEM-v2 Data

2019 ◽  
Vol 10 (1) ◽  
pp. 248
Author(s):  
Filippos Vallianatos ◽  
Maria Kouli
Keyword(s):  
Power Law ◽  
Statistical Physics ◽  
Drainage Basin ◽  
Tsallis Entropy ◽  
Drainage Basins ◽  
Tectonic Structures ◽  
Aster Gdem ◽  
Digital Elevation ◽  
Elevation Model ◽  
Of Greece

The drainage basins of Greece are analyzed in terms of hierarchy and discussed in view of Tsallis Entropy. This concept has been successfully used in a variety of complex systems, where fractality, memory and long-range interactions are dominant. The analysis indicates that the statistical distribution of drainage basins’ area in Greece, presents a hierarchical pattern that can be viewed within the frame of non-extensive statistical physics. Our work was based on the analysis of the ASTER GDEM v2 Digital Elevation Model of Greece, which offers a 30 m resolution, creating an accurate drainage basins’ database. Analyzing the drainage size (e.g., drainage basin area)-frequency distribution we discuss the connection of the observed power law exponents with the Tsallis entropic parameters, demonstrating the hierarchy observed in drainage areas for the set created for all over Greece and the subsets of drainages in the internal and external Hellenides that are the main tectonic structures in Greece. Furthermore, we discuss in terms of Tsallis entropy, the hierarchical patterns observed when the drainages are classified according to their relief or the Topographic Position Index (TPI). The deviation of distribution from power law for large drainages area is discussed.

scholarly journals Drainage basin morphometry: a global snapshot from the shuttle radar topography mission

2011 ◽  
Vol 15 (7) ◽  
pp. 2091-2099 ◽  
Author(s):  
P. L. Guth
Keyword(s):  
Digital Elevation Model ◽  
Drainage Basin ◽  
Shuttle Radar Topography Mission ◽  
Morphometric Parameters ◽  
Global Distribution ◽  
Drainage Basins ◽  
Basin Morphometry ◽  
Digital Elevation ◽  
Elevation Model

Abstract. A suite of 42 morphometric 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. At the scale of 15 arc s spacing (232 to 464 m) 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 generally more concave than the smaller basins.

scholarly journals Evaluation of Active Tectonics in Northwest of Saveh

2021 ◽  
Author(s):  
Bahar Rezaeinahal ◽  
Mohsen PourKermani ◽  
Mehdy Zare ◽  
Maryam Dehbozorgi ◽  
Reza Nozaem
Keyword(s):  
Drainage Basin ◽  
Active Tectonics ◽  
Tectonic Activity ◽  
Drainage Basins ◽  
The North ◽  
Level Of Activity ◽  
Digital Elevation ◽  
Arc Gis ◽  
Elevation Model ◽  
Gis Software

Abstract The northwest zone of Saveh city is located in the fault zone of the Indes, Koosh e Nosrat, Avaj and Aipak. Indes faults, Cox Nosrat, Avaj and Aipak are considered as the major faults of central Iran, which are also active in the Quaternary and the last movements of these faults are attributed to the present covenant, therefore, the estimation of morphometri in order to identify the effect of active tectonics on the tectonic evolution of drainage basins seems necessary. Therefore, in this study, six important morphotectonic indexes were analyzed; longitudinal gradient of the river, asymmetry of drainage basin, hypometric integral, Drainage basin shape,the ratio of the width of the floor to the height of the valley and forehead of the mountain is discussed.to create the basins on the studied area, Arc Hydro software (Arc GIS software) has been used based on data from a digital elevation model, Then, 6 morphotectonic indexes have been compiled and classified on each of the basins.Finally, according to which the region has been classified into 4 categories of high, medium and low tectonic activity the, Active Tectonic Index (IAT) has been calculated.According to the IAT index, 5% of the study area shows very high tectonic activity, 25% of the studied area has high tectonic activity, the average tectonic activity has 65% and about 5% of the tectonic activity are low. In this study, the highest level of tectonic activity is in the north-eastern part of the region. In most of the sectors, the level of activity is high and moderate, which is related to the activity of Koshk E Nosrat, Aipak, Avaj faults.

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 Improving estimation of glacier volume change: a GLIMS case study of Bering Glacier System, Alaska

2008 ◽  
Vol 2 (1) ◽  
pp. 33-51 ◽  
Author(s):  
M. J. Beedle ◽  
M. Dyurgerov ◽  
W. Tangborn ◽  
S. J. S. Khalsa ◽  
C. Helm ◽  
...  
Keyword(s):  
Volume Change ◽  
Balance Model ◽  
Drainage Basins ◽  
Landsat Images ◽  
Glacier System ◽  
Digital Elevation ◽  
Bering Glacier ◽  
Elevation Model ◽  
Dependent Mass

Abstract. The Global Land Ice Measurements from Space (GLIMS) project has developed tools and methods that can be employed by analysts to create accurate glacier outlines. To illustrate the importance of accurate glacier outlines and the effectiveness of GLIMS standards we conducted a case study on Bering Glacier System (BGS), Alaska. BGS is a complex glacier system aggregated from multiple drainage basins, numerous tributaries, and many accumulation areas. Published measurements of BGS surface area vary from 1740 to 6200 km2, depending on how the boundaries of this system have been defined. Utilizing GLIMS tools and standards we have completed a new outline (3630 km2) and analysis of the area-altitude distribution (hypsometry) of BGS using Landsat images from 2000 and 2001 and a US Geological Survey 15-min digital elevation model. We compared this new hypsometry with three different hypsometries to illustrate the errors that result from the widely varying estimates of BGS extent. The use of different BGS hypsometries results in highly variable measures of volume change and net balance (bn). Applying a simple hypsometry-dependent mass-balance model to different hypsometries results in a bn rate range of −1.0 to −3.1 m a−1 water equivalent (W.E.), a volume change range of −3.8 to −6.7 km3 a−1 W.E., and a near doubling in contributions to sea level equivalent, 0.011 mm a−1 to 0.019 mm a−1. Current inaccuracies in glacier outlines hinder our ability to correctly quantify glacier change. Understanding of glacier extents can become comprehensive and accurate. Such accuracy is possible with the increasing volume of satellite imagery of glacierized regions, recent advances in tools and standards, and dedication to this important task.

scholarly journals Topography and dynamics of Austfonna, Nordaustlandet, Svalbard, from SAR interferometry

1997 ◽  
Vol 24 ◽  
pp. 403-408 ◽  
Author(s):  
Beverley Unwin ◽  
Duncan Wingham
Keyword(s):  
Sar Interferometry ◽  
Synthetic Aperture ◽  
Drainage Basins ◽  
Ice Caps ◽  
Radar Images ◽  
Differential Interferometry ◽  
Digital Elevation ◽  
Radio Echo Sounding ◽  
Velocity Information ◽  
Elevation Model

The ice caps of Nordaustlandet, Svalbard, represent one of the largest glaciated areas outside of Antarctica and Greenland. They demonstrate a variety of different flow regimes within a comparatively compact area. We report on the first interferometrically derived elevation models and velocity visualisations of Austfonna. This initial investigation had three purposes: to determine whether the coherence and velocity characteristics of the region permitted interferometric survey; to determine the accuracy of derived elevations; and to assess the possibility of investigating time-variant flow of the more dynamic ice bodies using differential interferometry. A trio of coherent synthetic aperture radar images from ERS-1 ’s First Ice Phase was identified. The images were combined to separate the topographic and velocity components of the resultant interferograms. The topographic phase difference was used to produce a digital elevation model of Austfonna. Its accuracy relative to radio-echo-sounding derived tie-points is 8 m and its resolution 40 m. We also present synoptic views of the velocity field of three of Austfonna’s drainage basins, and comment on the extraction of useful velocity information.

scholarly journals A new 100-m Digital Elevation Model of the Antarctic Peninsula derived from ASTER Global DEM: methods and accuracy assessment

2012 ◽  
Vol 4 (1) ◽  
pp. 129-142 ◽  
Author(s):  
A. J. Cook ◽  
T. Murray ◽  
A. Luckman ◽  
D. G. Vaughan ◽  
N. E. Barrand
Keyword(s):  
Digital Elevation Model ◽  
Antarctic Peninsula ◽  
Accuracy Assessment ◽  
Correction Method ◽  
Pixel Size ◽  
Aster Gdem ◽  
Digital Elevation ◽  
Vertical Accuracy ◽  
Elevation Model ◽  
The Antarctic

Abstract. A high resolution surface topography Digital Elevation Model (DEM) is required to underpin studies of the complex glacier system on the Antarctic Peninsula. A complete DEM with better than 200 m pixel size and high positional and vertical accuracy would enable mapping of all significant glacial basins and provide a dataset for glacier morphology analyses. No currently available DEM meets these specifications. We present a new 100-m DEM of the Antarctic Peninsula (63–70° S), based on ASTER Global Digital Elevation Model (GDEM) data. The raw GDEM products are of high-quality on the rugged terrain and coastal-regions of the Antarctic Peninsula and have good geospatial accuracy, but they also contain large errors on ice-covered terrain and we seek to minimise these artefacts. Conventional data correction techniques do not work so we have developed a method that significantly improves the dataset, smoothing the erroneous regions and hence creating a DEM with a pixel size of 100 m that will be suitable for many glaciological applications. We evaluate the new DEM using ICESat-derived elevations, and perform horizontal and vertical accuracy assessments based on GPS positions, SPOT-5 DEMs and the Landsat Image Mosaic of Antarctica (LIMA) imagery. The new DEM has a mean elevation difference of −4 m (± 25 m RMSE) from ICESat (compared to −13 m mean and ±97 m RMSE for the original ASTER GDEM), and a horizontal error of less than 2 pixels, although elevation accuracies are lower on mountain peaks and steep-sided slopes. The correction method significantly reduces errors on low relief slopes and therefore the DEM can be regarded as suitable for topographical studies such as measuring the geometry and ice flow properties of glaciers on the Antarctic Peninsula. The DEM is available for download from the NSIDC website: http://nsidc.org/data/nsidc-0516.html (doi:10.5060/D47P8W9D).

scholarly journals A multi-level strategy for anticipating future glacier lake formation and associated hazard potentials

2010 ◽  
Vol 10 (2) ◽  
pp. 339-352 ◽  
Author(s):  
H. Frey ◽  
W. Haeberli ◽  
A. Linsbauer ◽  
C. Huggel ◽  
F. Paul
Keyword(s):  
Swiss Alps ◽  
Bed Topography ◽  
Aster Gdem ◽  
Digital Elevation ◽  
Lake Formation ◽  
Level 3 ◽  
Multi Level ◽  
Four Levels ◽  
Elevation Model

Abstract. In the course of glacier retreat, new glacier lakes can develop. As such lakes can be a source of natural hazards, strategies for predicting future glacier lake formation are important for an early planning of safety measures. In this article, a multi-level strategy for the identification of overdeepened parts of the glacier beds and, hence, sites with potential future lake formation, is presented. At the first two of the four levels of this strategy, glacier bed overdeepenings are estimated qualitatively and over large regions based on a digital elevation model (DEM) and digital glacier outlines. On level 3, more detailed and laborious models are applied for modeling the glacier bed topography over smaller regions; and on level 4, special situations must be investigated in-situ with detailed measurements such as geophysical soundings. The approaches of the strategy are validated using historical data from Trift Glacier, where a lake formed over the past decade. Scenarios of future glacier lakes are shown for the two test regions Aletsch and Bernina in the Swiss Alps. In the Bernina region, potential future lake outbursts are modeled, using a GIS-based hydrological flow routing model. As shown by a corresponding test, the ASTER GDEM and the SRTM DEM are both suitable to be used within the proposed strategy. Application of this strategy in other mountain regions of the world is therefore possible as well.

scholarly journals MORPHOTECTONICS OF THE PSATHOPYRGOS ACTIVE FAULT, WESTERN CORINTH RIFT, CENTRAL GREECE

2018 ◽  
Vol 40 (1) ◽  
pp. 500 ◽  
Author(s):  
Ch. Tsimi ◽  
A. Ganas ◽  
N. Soulakellis ◽  
O. Kairis ◽  
S. Valmis
Keyword(s):  
Drainage Basin ◽  
Normal Fault ◽  
Normal Faults ◽  
Rift System ◽  
Gulf Of Corinth ◽  
Digital Elevation ◽  
Hypsometric Integral ◽  
Landsat 7 ◽  
Morphotectonic Indices ◽  
Elevation Model

The study area is located on the western part of the Gulf of Corinth which is considered as a paradigm of an active rift system in Greece. This rift was formed by normal slip on big faults which extend the crust of the Earth in the N-S direction. The morphotectonic indices (hypsometric curve, hypsometric integral, drainage basin asymmetry, ratio of valley floor width to valley height) have been estimated using the 20-m digital elevation model of this area and the ARC software. The normal faults of the study area have been extracted by use of a DEM mosaic of 20-m pixel size, satellite images from Landsat 7 ETM+ and SRTM 90m. Our results highlight the recent activity of the Psathopyrgos normal fault on the basis of a series of morphotectonic evidence and suggest the existence of a single fault segment for a distance of 16 km.

scholarly journals Morphotectonic control of the Białka drainage basin (Central Carpathians): Insights from DEM and morphometric analysis.

2016 ◽  
Vol 5 (1) ◽  
pp. 61-82 ◽  
Author(s):  
Bartosz Wołosiewicz
Keyword(s):  
Drainage Basin ◽  
Research Area ◽  
Adjacent Area ◽  
Model Base ◽  
Base Level ◽  
Morphometric Analyses ◽  
Digital Elevation ◽  
Tectonically Active ◽  
Elevation Model ◽  
Central Carpathians

Abstract The Białka river valley is directly related to a deep NNW-SSE oriented fault zone. According to the results of previous morphometric analyses, the Białka drainage basin is one of the most tectonically active zones in the Central Carpathians. It is also located within an area of high seismic activity. In this study Digital Elevation Model (DEM) based, morphometric analyses were used to investigate the morphotectonic conditions of the watershed. The results reveal the relationships between the main tectonic feature and the landforms within the research area. The lineaments, as obtained from the classified aspect map, seem to coincide with the orientation of the main structures as well as the trends revealed by the theoretical Riedel-Skempton shear model. Base-level and isolong maps support the conclusion that the Białka and Biały Dunajec fault zones exert a strong influence on the morphology of the adjacent area.

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.

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