دانشگاه محقق اردبیلی مدل سازی و مدیریت آب و خاک 2783-2546 5 1 2025 03 21 Identifying Effective Factors and Landslide Risk Zoning using the Maximum Entropy Method(Case study: Chalus Watershed) شناسایی عوامل موثر و پهنه‌بندی خطر زمین‌لغزش با استفاده از روش حداکثر آنتروپی (مطالعه موردی: حوزه آبخیز چالوس) 247 264 2936 10.22098/mmws.2024.14799.1436 FA محمدرضا مهرپویا استادیار، گروه مخاطرات زیست‌محیطی، پژوهشکدة سوانح طبیعی، تهران، ایران محمد حسین قویمی پناه دانش‌آموخته دکتری، گروه مهندسی آبخیزداری، دانشکده منابع طبیعی، دانشگاه علوم کشاورزی و منابع طبیعی ساری، ساری، ایران. Journal Article 2024 03 14 Abstract Landslides are one of the most destructive types of domain movements and instabilities, which always cause soil erosion, produce sediment, destroy agricultural lands, gardens, and roads, and cause significant human and financial losses in different parts of the world. Especially in Iran due to the special conditions of the geological structure. The watershed of Chalus River is located in the northern slope of Central Alborz and in the south of the city in the geographical longitude of 51°, 00'east to 51°, 35' east and latitude 36°, 08' north to 36°, 43' north. The studied basin of Chalus River watershed leads from the west to the Sardabroud River watershed, from the east to the Korkorsar River watershed, from the south to the Karaj watershed, and from the north to the Mazandaran Sea. In this research, the most important factors affecting landslides have been investigated, which include topography, climate, geology, soil science, land use, distance from the river, topographic humidity index, and vegetation index. After determining the most important factors affecting landslides in the studied watershed, a layer map was prepared. Then, by using the maximum entropy algorithm with the help of MaxEnt software, one of the capabilities of this model is to identify the most important influencing variables and determine the relative importance of each of the factors affecting the identification of landslide areas and analyze the sensitivity of the model using the Jackknife method. In this method, after creating a complete model with the involvement of all variables, the modeling is repeated for the number of variables and each time one of the variables is removed from the modeling process. In this way, the effect of each variable in predicting the desired areas was evaluated. Then, in order to evaluate the model, the ROC curve was used, and the area under the obtained AUC chart was taken into consideration as a criterion of the model's discriminating power in detecting presence and non-presence points. In the next step, in order to prepare the stability index, SINMAP plugin and Arc view software were used. Then, by accepting the default values to recalibrate the parameters and apply the corresponding settings and values, the stability index was extracted. In the last stage of the current research, based on the effective factors in the Arc GIS10.8 software environment, a map of the risk of landslides in the Chalus watershed was prepared. According to the results of the model, the most effective factors in the occurrence of landslides in the study area were rainfall factors, soil science, geological units, slope percentage, land use and distance from the river. In the present study, AUC chart was used to validate the model. The number of output diagrams of the model is equal to the number of iterations of the model. Finally, the average of model iterations was considered as ROC diagram to evaluate the validity of the model. The value of AUC for landslide validation is 0.73, which indicates the acceptable prediction and modeling of landslides by the model in the study area. According to the results obtained from combining the results of the previous sections, the final map was prepared, which according to the findings of the research, the area and percentage of each of the landslide risk classes in the study area were obtained. In the landslide risk zoning map, the sensitivity of the region to the occurrence of this natural phenomenon was determined between zero and one. Due to the special geographical situation of Iran, each year the phenomenon of landslides imposes a lot of human and financial losses on our country, and one of the ways to reduce these losses is to identify areas prone to landslides with forecasting and zoning methods and providing implementation solutions. In general, it can be said that in all areas where the risk of landslides is more likely, there are formations with low resistance, suitable slopes to provide a landslide bed, and landslide prone landforms. Due to the fact that the role of each factor depends on other effective factors, so its role in the occurrence or non-occurrence of landslides is not the same, therefore, the combination of factors has created a suitable platform for the occurrence of this natural phenomenon. In this regard, in this study, with the aim of zoning landslide risk using the maximum entropy method in the Chalus watershed, it was planned that according to the results obtained from the current study, the risk classes were low, relatively low, medium, relatively high and high, respectively 13.29 , 18.57, 23.73, 35.90 and 8.49 percent of the studied area, which indicates the high potential of the area to cause landslides, so the results of this research can be useful to managers and planners. It helps a lot so that they can make better decisions based on location data. زمین‌لغزش‌ها یکی از مخرب‌ترین نوع حرکات و ناپایداری‌های دامنه‌ای هستند که همواره موجب فرسایش خاک، تولید رسوب، از بین بردن زمین‌های زراعی، باغی و جاده‌ها می‌شوند. همچنین باعث خسارات جانی و مالی قابل توجهی در نقاط مختلف جهان به ویژه در کشور ایران به دلیل دارا بودن شرایط خاص ساختار زمین‌شناسی و زمین‌ریخت‌شناسی می‌شود؛ به همین منظور در این پژوهش به پهنه‌بندی خطر زمین‌لغزش با استفاده از روش حداکثر آنتروپی در حوزه آبخیز چالوس استان مازندران پرداخته شد. جهت شناسایی مهم‌ترین متغیرهای تأثیرگذار و تعیین اهمیت نسبی هریک از عوامل مؤثر بر شناسایی مناطق زمین‌لغزش و تحلیل حساسیت مدل، از الگوریتم حداکثر آنتروپی به کمک نرم‌افزارMaxEnt استفاده شد؛ سپس به منظور ارزیابی مدل از منحنی ROC استفاده شد و سطح زیر نمودار AUC بدست آمده به عنوان معیاری از قدرت تفکیک مدل در تشخیص نقاط حضور و عدم حضور مورد توجه قرار گرفت؛ در نهایت بر اساس عوامل مؤثر، با استفاده از نرم‌افزار Arc Gis10.8 نقشه پهنه‎بندی خطر وقوع زمین لغزش در حوزه آبخیز چالوس تهیه شد. بر اساس نتایج حاصل از مدل، عامل‌های بارندگی، خاک‌شناسی، واحد‌های زمین‌شناسی، درصد شیب، کاربری اراضی و فاصله از رودخانه به ترتیب مؤثرترین عوامل در بروز زمین لغزش در منطقه مورد مطالعه معرفی شدند. مقدار AUC برای اعتبارسنجی پهنه لغزشی 73/0 به دست آمد که نشان‌‌دهنده شناسایی و مدلسازی قابل قبول زمین لغزش توسط مدل در منطقه مورد مطالعه بود. طبق نتایج به دست آمده از پژوهش حاضر طبقات خطر کم، نسبتاً کم، متوسط، نسبتاً زیاد و زیاد به ترتیب 29/13، 57/18، 73/23، 90/35 و 49/8 درصد از محدوده مورد مطالعه را به خود اختصاص دادند که این مهم نشان دهنده پتانسیل بالای منطقه جهت ایجاد زمین لغزش است؛ لذا با توجه به نتایج حاصل از این پژوهش، براساس عوامل مؤثر شناسایی شده، در مناطق دارای اولویت با راهکاری مناسب و تحلیل مسائل مدیریتی می‌توان جهت ارتقای سطح مدیریت حوزه‌های آبخیز و حفاظت خاک و آب برنامه‌ریزی نموده و خسارات ناشی از زمین لغزش را کاهش داد.

https://mmws.uma.ac.ir/article_2936_4d3dcefcff6772f4be678b02f46c604c.pdf