نوع مقاله : مقاله کامل علمی پژوهشی
نویسندگان
1 دانشجوی دکتری ،گروه جنگلداری، دانشکده علوم جنگل، دانشگاه علوم کشاورزی و منابع طبیعی گرگان، گرگان، ایران.
2 دانشیار، گروه جنگلداری، دانشکده علوم جنگل، دانشگاه علوم کشاورزی و منابع طبیعی گرگان، گرگان، ایران.
3 دانشیار، گروه مدیریت مناطق بیابانی، دانشکده مرتع و آبخیزداری، دانشگاه علوم کشاورزی و منابع طبیعی گرگان، گرگان، ایران.
4 دانشیار گروه جنگلداری، دانشکده علوم جنگل، دانشگاه علوم کشاورزی و منابع طبیعی گرگان، گرگان، ایران
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Abstract
Introduction and purpose: creeps and landslides, although small and shallow, occur abundantly in the vicinity of mountain forest roads and annually lead to considerable financial damage to technical buildings and roads. The main purpose of this research is to identify the most important factors affecting the occurrence of this type of roadside mass movement and to predict the location of their occurrence around the road.
Materials and methods: First, a part of the roads of Shamushak, Chelchai and Arab Dagh forestry projects, which have different climates and rock-beds, were surveyed and all the creeps and ground Landslides and their approximate extent were recorded by GPS. Natural influencing factors including the slope of the slope, the shape of the slope of the slope, the geographical directions of the slope, geology, height above sea level and the clay index of the soil through the collection of existing documents and field collection and ASTEM standards and the technical influencing factors of forest roads. It includes longitudinal slope, width and depth of air, height and slope of excavation trenches and embankment with the help of inclinometer and meter. The amount of traffic was determined through regional inquiry. All this information was entered in the random forest (RF) models and then based on the coefficients obtained from the implementation of the models, the most important influencing factors in the occurrence of creeps and landslides were identified. In the next step, based on the standardization of the obtained layers and coefficients, a sensitivity map or the probability of creep and landslide events was produced.
Results: The results of the ROC curve show the high accuracy of the random forest model with a kappa of 1 for landslides and a kappa of 0.95 for creep. Therefore, the results of zoning with a high percentage correspond to the ground reality. Also, based on the random forest model, the height and slope of the excavation trench respectively had the greatest effect on the occurrence of roadside landslides in the studied areas. The width and depth of the side air had the greatest effect on the occurrence of creep, respectively. Among the natural factors, the clay index of the soil and the geological condition of the region were the most effective factors in the occurrence of landslides and roadside creeps. According to the landslide and creep risk maps, 31% of the surface of the studied areas is prone to landslides and 51% of it is prone to creep.
Conclusion: This study showed that the non-standard dimensions of the side air caused by sediment accumulation or trench erosion can be the main driver of soil creep. Also, the design and construction of roads in steep lands leads to the creation of high and steep trenches, which is associated with the consequences of instability and landslides. These cases show the necessity of the basic design of the conductor path and comprehensive and accurate planning for the implementation of drainage operations and the protection and maintenance of forest road trenches.
کلیدواژهها [English]