تحلیل اثرات محسوس و نامحسوس زمین‌لرزه منطقه ازگله کرمانشاه بر لندفرم‌ها

زمین لرزه یکی از مهم ترین مخاطرات محیطی است که همواره با خسارت های زیادی همراه است. زمین لرزه افزون بر اثراتی که در نواحی سکونت گاهی دارد، روی لندفرم ها نیز اثرات محسوس و نامحسوس زیادی می گذارد که می تواند سبب بروز مخاطرات شود. با توجّه به اهمّیت موضوع، در نوشتار پیش رو اثرات محسوس و نامحسوس زمین لرزه ازگله بر لندفرم های منطقه بررسی شده است. داده های پژوهش شامل مدل رقومی ارتفاعی سی متر srtm، لایه های اطّلاعاتی رقومی، تصاویر سنتینل 1 و اطّلاعات به دست آمده ازراه بازدیدهای میدانی است. مهم ترین ابزارهای پژوهش شامل نرم افزار آرک جی.آی.اِس. به‌منظور تهیه نقشه و خروجی‌های نهایی) و gmt (برای انجام تداخل سنجی راداری) است. جستار حاضر در سه مرحله انجام شده است؛ در مرحله اوّل با استفاده از روش تداخل سنجی راداری، میزان جابه جایی عمودی منطقه محاسبه شده است. در مرحله دوم جابه جایی عمودی لندفرم‌های منطقه ارزیابی شده و در مرحله سوم، با استفاده از نتایج به دست آمده ازروش تداخل سنجی راداری و بازدیدهای میدانی، اثرات محسوس زمین لرزه بر لندفرم های منطقه بررسی شده است. نتایج پژوهش بیانگر این است که تحت تاثیر زمین لرزه ازگله منطقه بین 613- تا 917+ میلی متر جابه جایی داشته است. با توجّه به جابه جایی عمودی رخ داده در منطقه، لندفرم های منطقه نیز با جابه جایی زیادی روبه رو شده اند به‌طوری که دشت های واقع در منطقه نیز تحت تاثیر این جابه جایی بوده اند که بیشترین میزان جابه جایی با 382 تا 917 میلی متر بالاآمدگی مربوط به دشت ذهاب بوده است. برخلاف دشت‌های منطقه که جابه جایی و تغییرات صورت گرفته در آن ها به طور عمده به‌صورت نامحسوس بوده است، دامنه های واقع در منطقه افزون بر اثرات نامحسوس با اثرات محسوس زیادی نیز روبه رو شده اند، به‌طوری که بسیاری از دامنه های منطقه ازجمله دامنه‌های واقع در نزدیک روستاهای رمکی رمضان، مله کبود و قوچ باشی با زمین لغزش و همچنین دامنه های نزدیک به آبشار پیران و درّه بابا یادگار با ریزش روبه رو شده اند.

Analyzing Tangible and Intangible Effects of Kermanshah Ezgeleh Earthquake on Landforms

Earthquakes are one of the most important environmental hazards that always lead to a lot of damage. In addition to the effects that earthquakes on residential areas, they also have many tangible and intangible effects on landforms that can cause hazards. Due to the importance of the issue, the current study investigates the tangible and intangible effects of herd earthquakes on landforms in the Ezgeleh region. The research data includes the 30meter SRTM digital elevation model, digital data layers, Sentinel 1 images, and information obtained through field visits. The most important research tools include ARCGIS software (for mapping and final output) and GMT (for radar interference). This research has been done in 3 stages. In the first stage, using the radar interferometry method, the amount of vertical displacement of the area is calculated. In the second stage, the vertical displacement of the landforms of the region has been evaluated and in the third stage, the tangible effects of the earthquake on the landforms of the region have been investigated. The results of the research indicate that under the influence of earthquakes, the area had a displacement of between 613 and +917 mm. Due to the vertical displacement that has occurred in the region, the landforms of the region have also faced a lot of displacement so that the plains in the region have been affected by this displacement in which the highest displacement with 382 to 917 mm elevation is related to Zahab plain. Unlike the plains of the region in which the movement and changes have been mostly imperceptible, the slopes located in the region, in addition to the imperceptible effects, have also encountered many tangible effects. Therefore, many slopes of the region, including the slopes located near the villages of Ramaki Ramazan, Meleh Kaboud and Ghouchbashi have lnadslice, as well as the slopes near Piran waterfall and Baba Yadegar valley have Debriz.Extended Abstract1IntroductionEarthquake is a types of hazards that is associated with a lot of damage. Catastrophic earthquakes are one of the most devastating natural disasters, often leading to widespread casualties and high mortality. Besides, following the occurrence of this type of earthquake, human infrastructure will be severely damaged. Due to the fact that the Iranian plateau is located on the AlpineHimalayan seismic belt, it experiences about 8% of the world’s earthquakes and about 17% of the world’s major earthquakes. Given the above, earthquakes are a sudden natural hazard to which many parts of Iran are exposed. One of the earthquakes that occurred in Iran in recent years and caused great human and financial losses, was a 7.3 magnitude earthquake in Kermanshah on 2017/11/12. This earthquake has been accompanied by many tangible and intangible effects. Among its tangible effects are the destruction of residential areas, roads, bridges and other facilities, as well as sloping movements that killed and injured thousands of people in the west of Kermanshah province. In addition to the effects it had on residential areas, the quake also had many tangible and intangible effects on landforms in the area. Its intangible effects include vertical ground movement and its tangible effects include amplitude movements. According to the mentioned cases, the purpose of this study is to evaluate the tangible and intangible effects of the earthquake in Kermanshah herd using radar images and radar interferometry method.2Materials and MethodsThe research data includes the 30meter SRTM digital elevation model, digital data layers, Sentinel 1 images, and information obtained through field visits. The most important research tools include ARCGIS software (for mapping and final output) and GMT (for radar interference). In this study, 3 steps have been performed to investigate the effects of herd earthquakes on landforms in the region. In the first stage, in order to investigate the indirect effects of seismicity from the herd, first, using the radar interferometry method, the amount of vertical displacement of the area has been calculated. In the second stage, the amount of vertical displacement occurred in the landforms of the study area (plains and slopes) is investigated, which is considered as the imperceptible effects of the earthquake on the landforms. In the third stage, the tangible effects of the earthquake on the landforms are evaluated. After identifying these areas, the results were compared with the results obtained through field visits, and then the exact location of areas subjected to slip and fall amplitude movements was identified.3Results and DiscussionEarthquakes are sudden natural hazards to which large parts of Iran are exposed. One of the earthquakes that occurred in Iran in recent years and caused great loss of life and property, was a 7.3 magnitude earthquake in Kermanshah on 2017/11/12. This earthquake has been accompanied by many tangible and intangible effects. Among its tangible effects are the destruction of residential areas, roads, bridges and other facilities, as well as sloping movements that killed and injured thousands of people in the west of Kermanshah province. In addition to the tangible effects it has left, it has also had intangible effects that will be very important to be considered. One of the intangible effects of the earthquake from the herd is the vertical displacement of the region, which has caused the vertical displacement of residential areas, including urban areas. The results show that under the influence of earthquakes, the northern half of the region has subsided and the southern half of the region has also risen. According to the results, the maximum subsidence was 613 mm, and highest of which was in the epicenter. The maximum amount of elevation was 917 mm, the highest amount of which was close to the epicenter of the earthquake and decreased to the surrounding area. This shift has also had a great impact on geomorphological landforms, including plains and slopes located in the study area, which can have longterm detrimental effects in the region.4ConclusionThe results of the research indicate that due to the vertical displacement that has occurred in the region, the landforms of the region have also faced a lot of displacement so that the plains in the region have been affected by this displacement with the highest displacement with 382 to 917 miles. The elevation meter was related to Zahab plain. Unlike the plains of the region in which the displacement and changes have been mostly inconspicuous, the slopes located in the region, in addition to tangible effects, have also encountered many tangible effects. The results of the radar interferometry method as well as field visits indicate that many slopes of the region, including the slopes located near the villages of Ramaki Ramadan, Meleh Kaboud and Ghouchbashi, have encountered landslides, and also many slopes, from the slopes near Piran waterfall and Baba Yadegar valley have debriz. The total results of the research indicate that the earthquake from the herd had many tangible and intangible effects on the region, which in many areas, including the slopes of the blue mead, these effects were tangible. Besides, in many areas, such as the plains of the region, these effects have been imperceptible (only vertical displacement). The intangible effects of earthquakes on the plains, in addition to their harmful effects in the long run, can also be effective in many calculations, including the calculation of groundwater level, water level drop, etc. Moreover, these effects on slopes can cause rupture and instability of slopes and provide the ground for the occurrence of subsequent slope movements.