مخاطرات محیط طبیعی (Mar 2018)
The Active Morphotectonics Quantitative Assessment on the slopes of Alvand
Abstract
Neo-tectonic has a very important role in the morphological evolution of each drainage basin. The tectonic history can be retrieved by morphotectonics quantitative indicators in each region. Hamedan batholith masses valleys with NW-SE direction in the South, South East, and West of Hamadan, have been influenced heavily by the geomorphological, tectonic and other eroding factors. The core of tectonic geomorphology is the study of the frequency of tectonic processes that tend to topography and surface processes. By studying Morphotectonics indexes can be assessed valleys an unstable. Evaluation of Morphotectonics indicators in the northeastern and southwestern slopes of the mountain front sinuosity Hamedan according to different heights of mountain front is purpose of this study Evaluation of tectonic activity in Alvand mass range, have been estimated by using Morphotectonics indicators in 28 sub-basin, topographic maps with scale 1:50000, satellite images, field visits and software. The results of slope length of the river (SL), asymmetric factor (Af), integral hypsometric curve (Hi), valley floor width-to-height ratio (Vf), Mountain-front sinuosity (Smf), transverse topographic (Tp) and sinusoidal of river (Sr) indicators were assessed by using IAT index. According to this index, 50% of Northeast Slope sub-basins and 37.5% of southwest slope sub-basins have gained class 3 activities which imply a more active tectonics of the southwest toward the northeast slope. Due to the erosion and geological factors, south-west slopes tectonic activity is more evident than north-east slopes. The northeast slopes Mountain-front sinuosity is 200 meters higher than south-west slopes, according to the higher density of faults on the southern slopes of Alvand can say that the lower altitude mountain-front has provided favorable conditions for reflection Morphotectonics area.
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