Principle and geomorphological applicability of summit level and base level technique using Aster Gdem satellite-derived data and the original software Baz (original) (raw)
Related papers
2016
The main objective of this study is to assess geomorphic processes and active tectonics in the Day Nui Con Voi (DNCV) area of Vietnam. For this purpose, a spatial database was collected and constructed, including DEM (Digital Elevation Model) and a geological map. The hypsometric curve (HC) analysis method and its statistical moments were adopted to use for the assessment. These methods have been widely used for the assessment of geomorphic processes and active tectonics in many areas in the world showing promising results. A total of 44 sub-basins of the Red River and the Chay river were analyzed. The result shows that 3 curve-types such as "straight-shape", "S-shape", and concave were found; with the concave curve being the dominant and widely distributed in the northeast side and in the south of the southwestern side of the study area. The hypsometric integral (HI) values are rather small with the largest value is 0.37 and the smallest one is 0.128. Other statistical moments of the hypsometric curve, i.e. skew (SK), kurtosis (KUR), and the density function (density skew-DSK and density kurtosis-DKUR) show great values, which increased in the south direction of the area study. Accordingly, recent active tectonics (uplift-lower) in the study area is generally weak; however, they are also not completely homogeneous and can be distinguished by different levels. The southwestern side is being lifted higher than the northeastern side. The northern part is being lifted larger than the southern part. In the region, the uplift activities were increased gradually in the Pliocene-Quaternary and could have stopped at certain time in the past. The current geomorphic processes are mainly headward erosion in the upstream.
This paper presents the state of drainage erosion and three-dimensional concavity of Tijuca gneissic massif, Municipal District of Rio de Janeiro, Brazil, by means of geomorphologic analyses based on the ASTER GDEM. The massif has an extension of 15 x 10 km and relative height of 1000 m. The summit level maps show absence of marginal scarp and limited area of virtual plateau. The massif is divided into Tijuca Forest and Carioca Range by Alto da Boa Vista valley zone, which is wider than 2 km. Small rocky hills form five parallel chains with N60°E orientation. The base level maps present the drainages wider than 1 km striking to N45°E, which is different from the hill orientation. The narrow and short drainages at the highest range zone constitute a radial system. The areas of Tijuca Forest Range, Carioca Range, and Gávea Rock have high relief amount with the risk of large-scale landslide. They are characterised by subvertical gneiss exposures. The altitude distribution histogram shows an Eiffel Tower-like pattern, indicating concave three-dimensional landform of the massif. The volume-normalised three-dimensional concavity index (TCI) and macro concavity index (MCI) are, respectively, 0.54 and-0.5, which are significantly larger than those of the felsic alkaline massifs. The concave landform of Tijuca massif is attributed to erosive vulnerability of the gneiss because of low mechanical strength, gneissic texture, and low weathering passivity effects.
VIETNAM JOURNAL OF EARTH SCIENCES, 2016
The main objective of this study is to assess geomorphic processes and active tectonics in the Day Nui Con Voi (DNCV) area of Vietnam. For this purpose, a spatial database was collected and constructed, including DEM (Digital Elevation Model) and a geological map. The hypsometric curve (HC) analysis method and its statistical moments were adopted to use for the assessment. These methods have been widely used for the assessment of geomorphic processes and active tectonics in many areas in the world showing promising results. A total of 44 sub-basins of the Red River and the Chay river were analyzed. The result shows that 3 curve-types such as "straight-shape", "Sshape", and concave were found; with the concave curve being the dominant and widely distributed in the northeast side and in the south of the southwestern side of the study area. The hypsometric integral (HI) values are rather small with the largest value is 0.37 and the smallest one is 0.128. Other statistical moments of the hypsometric curve, i.e. skew (SK), kurtosis (KUR), and the density function (density skew-DSK and density kurtosis-DKUR) show great values, which increased in the south direction of the area study. Accordingly, recent active tectonics (uplift-lower) in the study area is generally weak; however, they are also not completely homogeneous and can be distinguished by different levels. The southwestern side is being lifted higher than the northeastern side. The northern part is being lifted larger than the southern part. In the region, the uplift activities were increased gradually in the Pliocene-Quaternary and could have stopped at certain time in the past. The current geomorphic processes are mainly headward erosion in the upstream.
Application of GIS for morphotectonic analysis (on the example of Kremenets Mountains)
2020
This study aims to show the possibility of using GIS for morphotectonic analysis of the territory that by the use of geomorphic indices helps us in reconstruction the stages of the development of the landforms during a certain period. On the example of Kremenets Mountains, the created maps of differences of isobase surfaces within the limits of the second, third and fourth orders are analysed. This is one of the methods of morphotectonic analysis. A map of the differences of the isobase surfaces of the second and third orders as well as a map of the differences of the isobase surfaces of the third and fourth orders are a part of created cartographic material. Based on them, two stages of influence of recent tectonic (mainly vertical) movements on this territory have been identified, which together with the processes of denudation and accumulation have formed a general appearance of the Kremenets Mountains. Within both stages, areas that have been significantly affected by modern tectonic uplifts and lowerings have been identified. The publication also presents several methodological aspects for constructing cartographic material for morphometric analysis.
Journal of Structural Geology, 2018
This study presents the importance of the accuracy of six digital elevation models (DEMs), in the calculation of the geomorphic indices and the classification of an active fault in the Gulf of Corinth, Greece. Four of the DEMs used are based on public and global satellite imageries, the SRTM90, SRTM30, ASTER and ALOS. The other two are national DEMs: the Greek Cadastral DEM and the topographic maps of 1:5000. We applied in each DEM, for drainage basins oriented perpendicular to the fault, a series of geomorphic indices such as the drainage basin shape (Bs), the asymmetry factor (AF), the stream length-gradient index (SL), and the valley floor width to valley height ratio (Vf). These indices are used worldwide for fault activity classification. The indices calculated in the selected DEMs are compared with results from the Greek Cadastral DEM. Bs values range from 1.6 to 5.9 suggesting variably active basins, elongated according to Drainage Basin Form (RF) calculations. AF suggests systematic tilt down to the east or west. These three indices show high variability between different DEMs. Values of SL are relatively high close to the fault trace and range from 10 to 4500 and their visualization shows different narrow or inclusive patterns. Vf values range between 0.04 and 5.00 corresponding to an almost inactive fault when based on the SRTM 90 DEM to highly active using the Cadastral DEM. Our results suggest that the globally available ALOS products are quite accurate for the purposes of the tectonic geomorphology.
2014
This paper presents morphological analyses for Morro de São João felsic alkaline intrusive massif, State or Rio de Janeiro, Brazil, with the help of summit level and base level map techniques and the satellite digital elevation model of ASTER (GDEM). The summit level maps shows the steep marginal scarp of about 30º, the virtual plateau of 480 m to 500 m of altitude, and the top swell with relative height of 150 m. The marginal scarp is steep, not only on the summit level maps but also on the base level ones. The maps for the difference between summit and base levels, called relief amount map, demonstrate the presence of high declivity zone along the border of the intrusive body and gentle relief area on the central highland. These observations indicate high erosive resistance of the constituent rocks of this massif. The drainages form a radial system. They are shallow, short, and steep, in average 20 m deep, 1.1 km long, and of 22° in declivity. Most of the longitudinal profiles are straight and not concave. The macro concavity index (MCI) is-1.2, showing that the general 3D form of this massif is highly convex, which is widely different from that of volcanic edifices. Therefore, the conical form of this massif is not originated form an extinct volcano, but differential erosion of the nepheline syenite intrusion, which has strong erosive resistance due to mechanical firmness and weathering passivity.
Geomorphology, 2004
A complex application of digital elevation model (DEM) derivatives is presented for a highly degraded volcanic area, the Miocene Börzsöny Mountains, Hungary. We propose unconventional geometrical and mathematical transformations of the original DEM data in order to enhance the topographic features of the volcanic relief that stem from the primary landforms. It is the actual ridges that represent the least degraded surfaces of an original, hypothetical volcanic cone. Therefore, the statistical DEM properties such as ridge pattern (1), slope angle distribution (2) and higher-order slope derivatives (3) should be strongly correlated with the paleosurface. Automated creation of a ridge pattern image is based on the local histogram of the DEM, and helps to outline the original surface remnants. A local slope angle histogram may point out structurally coherent parts of the original cone: for instance, tectonic displacements or large-scale sector slumping does not affect the slope angle histogram of the original relief. Evaluating the ridge maps and slope aspect maps of the Börzsöny Mountains allows various cone sectors to be identified and connected to the original volcano-structural elements. Finally, the polar coordinate-transformed (PCT) image (4) centered on a hypothesized eruptive vent enhances the original, radial valley pattern. In the case of multiple eruptive centers and/or post-eruptive tectonic modifications, the radial pattern is changed, which may be evidenced in the PCT image. In fact, the PCT image analysis for the Börzsöny Mountains suggests a complex post-eruptive tectonic scenario. The presented methods can be recommended to infer the original configuration of highly degraded volcanic structures with poorly known tectonic and erosional history. D
Analysis of the current state of unstable geomorphological structures with modern methods
GEOGRAPHY, ENVIRONMENT, SUSTAINABILITY
The paper gives results of the digitization of the status and spatial position of a cliff in the Western Crimea coastal zone. The modern equipment and methods accelerate the survey from the time perspective and improve the quality of the outcomes; namely a high precision GNSS receiver in RTK mode and PHANTOM-3 PRO copter. The digital terrain model was generated with used the Agisoft Photoscan software. The paper shows that the precision of the mathematical model of the relief constructed by aerial photographs provides more detailed data in comparison to those obtained in the field observations. Furthermore, aerial photography makes it possible to calculate the number of spatial characteristics of hazardous for surveying and latent natural objects out of reach for an on-location investigation. As a result, the very detailed data about current condition of dangerous cliff were obtained. The paper also evaluates the linear and volumetric characteristics of cleavages that are prone to c...