Afarand Journals

Geographical Research

eISSN : 2538-4384
pISSN : 1019-7052
Persian
Language
Geographical Research is Published in Persian Fulltext.

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Showing 5 results for Morphotectonic
Neotectonic Analysis in the North Slope of Bozqoosh Mountains, by Using Geomorphological Methods
Dr Fariba Karami , Dr Massumeh Rajabi, Maryam Asgari ,
Volume 28, Issue 2 (9-2013)
Abstract
The aim of this study is analysis of drainage basins neotectonic in the north slope of Bozqoosh Mountains by geomorphological methods. To attain this aim، It used of field observation، areal photographs and five geomorphic indexes in 20 basins of the north slope of Bozqoosh Mountains. Indexes were calculated by topography maps (1: 50000)، geological maps (1: 100000) and areal photographs (1: 20000). All of maps drew by Arc/GIS. The results show that 40 % of drainage basins in study region have high activity tectonic. This basins located in middle portion of Bozqoosh Mountains. 35% of basins have moderate values of tectonic activity. They located in eastern portion of study region. 25% of basins of Bozqoosh have shown the lowest values of tectonic activity. There are numerous of morphotectonic evidences such as fault scarps، alluvial fans، fault valley، water fall and etc. which are in the north slope of Bozgoosh Mountains with high activity tectonic

Structural analysis of Piranshahr fault as the northest part of Zagross Main Resent Fault by using DTM model and GIS
Camellia Yazdanfar ,
Volume 29, Issue 4 (3-2015)
Abstract
Tectonic، plays a key role in the evolution of morphology and can be distinguished with morphotectonic، rivers and structural parameters. An analysis of morphometric parameters illustrates that the development of them is associated with faults activities and rocks resistance. Morphotectonic analysis also supplies seismotectonic setting for a region. For appropriate and survey tectonic activities of Piranshahr fault in south west of Azarbaijan province as Northest part of Zagross Main Recent Fault، the morphotectonic indices contain: Ratio of Valley-mouth width to Valley Height، Ratio of Valley-floor width to Valley Height، Ratio of Vc and Mountain Front Sinuosity has been calculated. The results of several indices are incorporated to highlight tectonic activity and provide an assessment of a high degree of morphotectonic، Neotectonic activities. Piranshahr fault with 95 km length produced a seismic hazard magnitude ~ 6.9 in Richter scale.

Assessment of watershed Tectonic Activities in Southwest Side of Sabalan by Geomorphologic Characteristics
Masomeh Rajabi, Mir Ebrahim Hashemian,
Volume 32, Issue 1 (6-2017)
Abstract

Assessment of watershed tectonic activities is interesting for earth science researchers, especially tectonic geomorphology. In this regard, different methods have been used by researchers. These methods have been constantly developing and they consist a range of Geomorphometric methods, remote sensing, Digital Elevation Models (DEM) and other advanced techniques. In this study the remote sensing methods, Digital Elevation Model and geomorphic indicators (in the form of TecDem) were used to evaluate tectonic activity in southwest side of Sabalan Mountain. To determine the boundary of drainage basins Arc Hydro Model was used. The indices of concavity (Ѳ), slope (S), Iso Base Map and the profile of distribution slope with regression of log Networks were extracted from Digital Elevation Model and then the tectonics uplift rate of basins was calculated by using Stream Power Model. By using morphometric parameters and geomorphic indicators such as Transverse topographic symmetry factor (T), Stream Length-gradient index (SL) and Hypsometric integral (HI) in TecDem Model; Tectonic activities were evaluated in the studied basins. The results of the extracted components (i. e. distribution logarithmic regression of networks and slope, skewness values, Hypsometric integral, Iso Base Map, knick points and steepness and uplift rates proved dominance of active tectonic in the studied basins. So that the uplift tectonic rate is 0.33 to 0.51 mm/yr. Also, low indices of concavity (0.24 to 0.45) and high values of maximum gradient (80.6 to 132.2 percent) confirm the existence of high tectonic activity in study area. Accordingly, the results of surveys and morphotectonic evidences such as linear valleys, reverse fault scarps in Tajyar and Aghmiyun basins, the Shutter and liner rides along the Aghmiyun and Tajyar networks, replacement of Fan apex and diversion of networks caused by fault activity in southwest of Sabalan; prove the presence of active tectonics and good efficacy of TecDEM Model in evaluation of Tectonic Activities in study area.


Investigating the Role of the Movements of Khorram Abad’s Hidden Thrust Fault in the Evolution of Khorram Abad River’s Drainage System
H. Arian Tabar , E. Jabbari , Mm. Farahpour ,
Volume 36, Issue 2 (3-2021)
Abstract
Aims: Khorram Abad plain is located in the folded Zagros zone and its River, as one of the main rivers discharging to Karkheh River, flows through this plain. This region is highly influenced by the neotectonic activities of this fault since Khorram Abad’s hidden and active fault is located in this region. Therefore, the current study aimed at the investigation of the effect of this fault’s activities on the morphological activities of Khorram Abad River.
Methodology: This is an empirical study that is quantitative in terms of used data and calculations. Remote-sensing techniques, geometrical indices, aerial photos, satellite images, and field studies are used in the current research. For this purpose, the river’s route was divided into five subzones to be more precise. Then, the aerial photos taken in 1955 were compared to Google Earth’s 2016 images in GIS. Geometrical indices such as the gradient of the river’s slope and sinuosity of the mentioned five subzones were calculated by the digitization of the river’s route in AutoCAD; the profiles and the changes in the alluvial terraces were measured through field observations.
Findings: Khorram Abad River’s geometrical indices indicated that Khorram Abad’s anticline and its upstream regions are upheaving and the downstream regions are subsiding or staying in their previous positions. This ascending trend has been followed by an increase in the average river's slope has changed the number of the tributaries and geometrical properties of the river.
Conclusion: The primary reason for the morphological changes in the Khorram Abad River is the geological movements. Then, the movements of Khorram Abad hidden thrust fault were the most important factors changing the morphology of Khorram Abad River in the studied period.

Evaluation and analysis of Tectonic Activities in Sivand Basin area using Morphometric Indices
M. Khalaj,
Volume 38, Issue 3 (10-2023)
Abstract
Aims: Morphometry can be defined as a quantitative measurement of the shape of landscapes on the ground, which can be used to identify areas with active tectonics. The purpose of this research is to investigate the active tectonics in the Sivand basin using five morphometric indices of Asymmetry factor of the drainage basin (Af), Relative relief (Bh), Form factor (Ff), Hypsometric integral and curve (Hi) and Stream gradient index (SL). By conducting this research, it is possible to understand the active processes in the Sivand basin and prevent damages caused by natural disasters such as floods and earthquakes to some extent.
Methodology: This is a survey carried out in 2022-2023 in Fars province and it is a practical study in terms of its purpose. The nature of the data and their calculations are quantitative. GIS software and digital elevation map (DEM) with an accuracy of 30 meters, were used to calculate the indices. For each index, a zoning map was prepared in the area, and each of the mentioned indices was classified into five categories very high, high, medium, low and very low geotechnical activity. Finally, by averaging the entire category of indices, a final index of relative active tectonics index (Iat) was obtained and the area was classified into three categories of high, medium and low terraforming activity.
Findings: In the sub-basins of Avanjan Fault, Musakhani Fault, Sivand Fault, Sivand river Fault and the faults located in the south of the investigated area, the measured indices showed high and medium values, which is due to the medium to high tectonic activity of the area.
Conclusion: The Sivand basin has medium to high tectonic activity and the northern, northwestern, middle and southern parts of the region are more active than other parts. It is due to the effect of the mentioned faults on the region.

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