Prioritization of effective factors in aggravation of instabilities resulting from seismic earthquakes in Ilam and Kermanshah using Vikor method

Subject Areas :

fathollah naderi ¹ , Samad Fotouhi ² , Hossein Negarash ³ , Marzieh Khalili ⁴

1 - Department of Natural Geography, Faculty of Geography and Environmental Planning, Sistan and Baluchestan University
2 - Department of Geomorphology, Faculty of Geography and Environmental Planning, Sistan and Baluchestan University, Zahedan, Iran
3 - Department of Geomorphology, Faculty of Geography and Environmental Planning, Sistan and Baluchestan University, Zahedan, Iran
4 - Department of Geology, Faculty of Earth Sciences, Shiraz University, Shiraz, Iran

Received: 2021-08-26 Accepted : 2021-08-26 Published : 2020-11-21

Keywords: zoning, Ozgeleh earthquake, Geomorphological instabilities, Young Zagros fold,

Abstract :

The main purpose of this study is to study the geomorphological instabilities resulting from the Ozgeleh earthquake in Kermanshah and Ilam provinces using field studies and satellite images and their zoning. The region affected by this earthquake is very prone to various movements and geomorphological instabilities. The reasons for this are the presence of young Zagros folds along with the operation of their cutting faults, which have caused severe fractures in the region. To conduct this study, first, the geomorphological instabilities of the index that were effective in intensifying the damage caused by the earthquake were identified. Then, using topographic maps, geology, satellite images and field operations, their location was determined. These instabilities include landslides, rock falls and avalanches, currents, hilltop ruptures, and landslides. Using multi-criteria decision making (MADM) method, the study area was zoned in terms of instabilities. The zoning results showed that the two very high risk classes and the high risk class with a total area of ​​6558 square kilometers, i.e. more than 28% of the study area and among the factors affecting the occurrence of instabilities, land age factors Histology, distance from fault and slope with 0.23, 0.22 and 0.15 points, respectively, have the greatest impact on creating instabilities in the region. The adaptation of the instability zoning map to the instability distribution map indicates the greater adaptation of the instabilities, including landslides, rock falls, and subsidence, to high-risk classes.