پديد آورندگان :
سپهر ، عادل نويسنده استاديار دانشكده منابع طبيعي و محيط زيست، دانشگاه فردوسي مشهد , , بهنيافر ، ابوالفضل نويسنده استاديار ژيومورفولوژي، دانشگاه آزاد اسلامي، واحد مشهد , , محمديان ، عباسعلي نويسنده دانشجوي كارشناسي ارشد آبخيزداري، دانشگاه يزد , , عبداللهي، ابوالفضل نويسنده دانشجوي كارشناسي ارشد سنجش از دور، دانشگاه خوارزمي ,
كليدواژه :
الگوريتم بهينه‌سازي توافقي ويكور , حساسيت پذيري , دامنه‌هاي شمالي بينالود , زمين‌لغزش
چكيده فارسي :
ناپايداري هاي دامنه‌اي، ازجمله پديده هاي معمول در بيشتر مناطق كوهستاني ايران است. در اين ميان يكي از مخاطره‌آميزترين اين ناپايداري‌ها، زمين‌لغزش است. هدف از اين پژوهش، تهيه نقشه حساسيت پذيري دامنه‌هاي شمالي بينالود به زمين‌لغزش با استفاده از الگوريتم بهينه‌سازي توافقي ويكور است. ابتدا پس از تهيه نقشه پايه محدوده مطالعاتي با استفاده از تصاوير ماهواره اي و بازديد‌هاي ميداني، نقشه عوامل موثر در حساسيت پذيري حوضه به زمين‌لغزش شامل شيب، فاصله از گسل، طبقات ارتفاعي، تراكم زهكشي، كاربري اراضي، پوشش گياهي، ليتولوژي، نوع خاك و بارش در محيط GIS تهيه شد. سپس ضريب اهميت هر كدام از معيارهاي مذكور در وقوع زمين‌لغزش، بهكمك الگوريتم سلسلهمراتبي AHP بهدست آمد كه معيارهاي شيب، ليتولوژي و طبقات ارتفاعي بيشترين ضريب اهميت را كسب كردند. سپس بر پايه الگوريتم بهينه‌سازي ويكور، درجه سودمندي و پشيماني انتخاب گزينه هاي برتر (زيرحوضه ها)، مشخص و در پايان با محاسبه ميزان شاخص بهينه ويكور (Q)، زير‌حوضه‌ها برحسب درجه حساسيت پذيري به زمين‌لغزش در سه كلاس كيفي حساسيت‌پذيري كم، متوسط و زياد طبقه‌بندي و رتبه‌بندي شدند. نتايج نشان داد كه زير‌حوضه‌هاي گلمكان، اسجيل و اندرزي بيشترين حساسيت‌پذيري و زير‌حوضه‌هاي خيرآباد، اقبال و چايش داراي كمترين حساسيت‌پذيري بهوقوع زمين‌لغزش هستند.
چكيده لاتين :
Introduction
Hill slope instabilities are common phenomena in the mountain regions. Landslide is one of the main hazards of the hill slope movements. Landslides cause enormous loss of life and property every year in mountainous areas. Landslides, a major geologic hazard in the Iran, occur in most areas and cause compensation damages each year. In such regions, landslide susceptibility zonation is very necessary with a view to delineate the disaster prone areas. Landslides mostly result from triggering events, like earthquakes, intense rainfall, and snow melt. Besides triggering events, other factors can be responsible for the instability of the hillslope, including geology, land cover, slope geometry, solar radiation, surface and subsurface hydrology, and the role of people. When assessing susceptibility to landslides, the role of each of these factors needs to be evaluated. Besides these factors, landslide frequency and magnitude are also necessary in an assessment. Frequency and magnitude of landslides are rarely introduced in the assessment of susceptibility to landslides. Several methodologies have been suggested for landslide hazard/susceptibility zonation.
The purpose of this research is mapping landslide susceptibility in the northern Binaloud based on the VIKOR algorithm.
Methodology
In the first step, after providing study area border map, the quality map of the main criteria affecting landslide susceptibility were prepared. The criteria involved slope, fault distance, hypsometry, drainage density, land use types, vegetation cover, lithology, soil type and precipitation. The preference coefficient of the criteria was calculated by AHP algorithm. The criteria of slope, lithology and hypsometry gained the high preference coefficient. Ultimately, based on the VIKOR algorithm, the suitability and regret amounts were measured. Ultimately, the VIKOR index (Q) was calculated and with this technique, landslide susceptibility map categorized the catchment into low, moderate, and high susceptible zones with respect to landsliding were developed.
Results and Discussion
The results showed the Golmakan, Asjil and Andarzi are high vulnerable and susceptible to landslide. Also Kheirabad, Chayesh and Eghbal were categorized in low vulnerability class. The findings indicate that 75 % of studied area hillslope have high landslide susceptibility at least. The slope showed the highest weight index, Steep slope with negative curvature values and high proximity to river network areas were found as more susceptible to landslides. Concave- and convex-shaped curvature types are susceptible than the other types of topographic shapes. The second important parameter contributing to landslide occurrence is lithology. The third important parameter contributing to landslide occurrence is elevation levels. Vegetation index and soil types play the next important role on landslide occurrence in the study area.
Vegetation protection, landuse management, soil moisture conservation and restoration methods are in preference for high susceptible zones.
Conclusion
Landslides, which are common in mountainous areas, involve the rapid down-slope movement of the material, consisting of either the superficial formation belonging to the root zone or the bedrock and the overlying weathered horizon. Further, landslides of large dimensions may cause damage to property and loss of human lives also. In this research for mapping landslide susceptibility was applied the VIKOR algorithm for first experience. The results of this study can be of great help to prepare risk maps for the Binaloud watershed and to be used in disaster management planning.
