نوع مقاله : پژوهشی کاربردی
نویسندگان
1 دکتری ژئومورفولوژی، دانشگاه تهران، تهران، ایران
2 کارشناس ارشد ژئومورفولوژی، دانشگاه کردستان، سنندج، ایران
3 دکتری ژئومورفولوژی، دانشگاه تبریز، تبریز، ایران
4 کارشناسی منابع طبیعی مرتع و آبخیزداری، دانشگاه ملایر، ملایر، ایران
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Natural hazards are one of the most important challenges for the advancement of mountain areas. One of the areas exposed to natural hazards is the Oraman region in the west of the country. Considering the importance of the subject, in this research, the vulnerability of the villages of Oraman region to natural hazards has been evaluated. Descriptive-analytical methods have been used in this research. The most important research data were the digital model of 30 meters high STRM, the digital layer of 1:100000 geological maps of the area and the information layers related to the used parameters. The most important used tools were ArcGIS and Expert Choice. Fuzzy-AHP integrated model is also used in this research. In this study, the vulnerable areas against landslides, floods and earthquakes have been identified first, and then a map of the region's risk status has been prepared. The results of this study have shown that the central areas of Oraman (including the villages of Bargharo, Nayabad, Degagah, Maziben, Nasl and Boridar) have high vulnerability potential in terms of all three hazards (landslides, earthquakes, and floods). More findings show, it can be said that the Oraman region has a high vulnerability potential against natural hazards, so it is necessary to consider factors such as the stability of buildings against earthquakes in the development planning of this region, Determining the boundaries of rivers and preventing settlements from advancing towards them in flood-prone areas, as well as the potential for slope movement.
Extended Abstract
Introduction
In recent years, under the influence of the increasing trend of population, residential and man-made areas have been associated with a lot of growth, and considering that in many areas, the environmental strength of the region has not been paid attention to, the development of these uses increases the possibility of Risks have become normal. Based on this, the increase and intensity of some natural hazardous events are under the direct influence of human activities. The surveys conducted on natural hazards indicate that these hazards are on the rise and millions of people around the world are exposed to them. The vulnerability of residential areas to natural hazards is influenced by various geomorphological, geological and hydroclimatic factors, and each area may be exposed to one or more types of hazards. One of the areas that are exposed to several types of natural hazards is the Oraman region in the west of the country. The location of the Oraman region in the Zagros mountain unit has caused a large part of this region to be included in the mountain unit and considering that the Oraman mountains have significant snowfall and also considering the proximity to the main fault lines and the tectonic nature of the area. This area is exposed to the dangers of earthquakes, landslides and floods. Considering the importance of the subject, in this research, the vulnerability of the villages of Oraman region to natural hazards has been evaluated.
Methodology
Descriptive-analytical methods have been used in this research. The most important research data were the digital model of 30 meters high STRM, the digital layer of 1:100000 geological maps of the area and the information layers related to the used parameters. The most important tools used were ArcGIS (executing the Fuzzy-AHP model and preparing the desired maps) and Expert Choice (weighting the desired parameters). Fuzzy-AHP integrated model is also used in this research. According to the subject and objectives, this research has been done in 4 general stages. In the first stage, by using 8 parameters of height, slope, direction of slope, distance from the river, distance from the communication road, type of land use, lithology and distance from the fault, vulnerable areas against slope movements have been identified. In the second stage, by using 6 parameters of slope, slope direction, height, distance from the river, land use and lithology, vulnerable areas against floods have been identified. In the third stage, by using 4 parameters of distance from the fault, distance from earthquake epicenters, lithology and slope, vulnerable areas against earthquakes have been identified. In the fourth stage, based on the results obtained from the previous stages, the hazard map of Oraman region has been prepared.
Results and Discussion
Examining the geomorphology and geology of the region shows that this region has a high potential for the occurrence of hazards caused by slope movements, floods and earthquakes. The results of the identification of areas prone to landslides have shown that many parts of the area are prone to landslides, the main reason of which can be considered the existence of steep slopes and undercuts caused by the river and communication road. The results of the evaluation of the region's vulnerability to flood risk have shown that considering that a large part of the studied area is located in the mountain unit, therefore only a few parts of the area that are located near the river and at low altitudes are in They are at risk of flooding. Also, due to the fact that a large part of the studied area is located in the vicinity of fault lines and earthquake epicenters, and also due to the mountainous nature of the area, this logic has a high vulnerability potential against earthquakes.
Conclusion
The natural condition of Oraman region has caused this region to have a high risk potential. Investigations have shown that in recent years, this area has been faced with various hazards such as landslides, floods, and earthquakes, and this is the reason for investigating these hazards in this area. The results of this research have shown that the central areas of Oraman, including the villages of Bargharo, Nayabad, Degagah, Maziben, Nasl and Boridar, because they have the potential of damage in terms of all three hazards (landslides, earthquakes and floods). They are highly adaptable, they are considered as the most vulnerable villages in Oraman region. According to the obtained results, it can be said that the Oraman region has a high vulnerability potential against natural hazards, so it is necessary to consider factors such as the stability of buildings against earthquakes in the development planning of this region. Special attention should be paid to rivers and preventing settlements from moving towards them in flood-prone areas, as well as the potential of slopes.
کلیدواژهها [English]