توسعه نمودار نرخ پيش بيني _ مساحت به منظور بهبود خروجي مدل هاي پتانسيل خطر زمين لغزش

Development of Prediction - Area charts to improve the output of landslide potential models

هدف از انجام پژوهش حاضر توسعه نمودار نرخ پيش بيني _ مساحت براي پهنه بندي خطر زمين لغزش مي باشد. به اين منظور پس از تعريف يك مدل توصيفي و مفهومي در برگيرنده متغيرهاي موثر در پهنه بندي خطر زمين لغزش، همه مشخصاتي كه مي توانند به عنوان معيارهاي مناسب مورد استفاده قرار گيرند، شناسايي و در قالب يك مدل هدف جمع آوري گرديد. سپس با استفاده از تجزيه و تحليل لايه هاي اطلاعاتي مختلف و وزن دار نمودن آنها با كاربرد تابع لجستيكي به منظور مدلسازي و پهنه بندي خطر زمين لغزش، نقشه هاي وزن دار به طور پيوسته و بدون ساده سازي توليد گرديدند. وزن هر كدام از لايه ها با استفاده از چگالي نرمال شده مشخص شد. در نهايت كليه نقشه هاي وزن دار با استفاده از روش شاخص همپوشاني داده محور با هم تلفيق شدند. نتايج اين پژوهش نشان داد كه اهميت نسبي متغيرهاي تاثيرگذار در بروز زمين لغزش مي تواند با استفاده از نمودار نرخ پيش بيني _ مساحت به طور كمي مورد ارزيابي قرار گيرد. بنابراين لحاظ نمودن وزن كمي محاسبه شده با استفاده از نمودار نرخ پيش بيني _ مساحت، چگالي نرمال شده، در رابطه شاخص همپوشاني داده محور موجب توليد مدل هاي پتانسيل خطر زمين لغزش قابل اعتمادتر شده و توانسته همچنين 55 درصد نقاط زمين لغزش را در 45 درصد مساحت كل منطقه شناسايي كند. كاربرد مدل توسعه داده شده در حوضه آبخيز عشوند-نهاوند اثبات نمود كه مدلسازي به روش فوق مي تواند به نحوه مطلوبي مناطق پرخطر را جهت بررسي هاي بيشتر صحرايي شناسايي نمايد.

Landslide is one of the types of mass movements involving the jogging of rock, earth or aggregate both on the downward slope affected by gravity. This is one of the natural disasters that causes huge loss of life and financial loss in different countries every year. Therefore, it is important to investigate the factors affecting the occurrence of this phenomenon and to determine landslides. The purpose of the present study is to develop a forecast-area rate chart for landslide hazard zoning. Landslide zoning is one of the ways in which the critical areas can be identified in terms of slope stability and the zoning maps obtained in sustainable development planning. Zoning is the division of land into several zones and the classification of these zones according to the degree of actual or potential risk of a phenomenon. Landslide hazard zoning maps can be used as a useful tool for managers and decision makers to determine suitable locations for the development of residential areas and critical arteries. Landslide studies in the past have mostly been done to stabilize instability in natural slopes and to carry out specific projects, and engineers have developed techniques in this field to design structures to control slope instability. Extensive variations in geotechnical properties of materials, internal friction angle (Փ) and adhesion coefficient (C), heterogeneity of natural environments at regional and regional scales compared to homogeneity in local and expensive models, and time-consuming exploration techniques. The desert makes old ways inappropriate. Because this seems unreasonable given the cost to profit ratio, especially in the early stages of decision making in engineering projects. To address this problem, taking into account that landslide risk assessment should be based on a careful study of the natural conditions of an area and all possible parameters involved in slope instability should be analyzed seriously in the area of ​​landslide hazard zoning. Was Initial measures in this area should be based on field studies and analysis of instability relationships in slopes and natural and geographical conditions. The results of engineering geological and geomorphological surveys that pay particular attention to minor landslide issues are generalized to the entire study area with no instability observed in its natural slopes and to sites that are naturally occurring. an‎d geographies of landslide conditions are being searched. For this purpose, after defining a descriptive and conceptual model including landslide hazard zoning, all the features that could be used as suitable criteria were identified and collected in a target model. Then, by analyzing different information layers and weighting those using logistic function, control maps and weighted prediction were obtained. In this regard, for the first time to weighted landslide hazard maps, weighted maps were produced continuously, without classifying and simplifying the data into different parts, as well as minimizing expert judgment. It was also identified using the Prediction - Area chart of each layer and identifying the most important factor affecting landslide occurrence for the first time without expert judgment. Finally, all the weighted maps were integrated using the data-driven overlay index method.It was also able to identify 55% of the landslide points in 45% of the total area. Application of the developed model in the Oshvand-Nahavand watershed proved that modeling the above method can optimally reduce the studied areas and reduce the objectives. Identify for further field surveys.