Kourosh Shirani; Reza Naderi Samani
Abstract
The aim of this study is to prioritize effective factors, landslide susceptibility zonation assessment using maximum entropy (MaxEnt) and dempster shafer models in Doab Samsami watershed of Chaharmahal and Bakhtiari province. For this purpose, 15 factor maps affecting landslide occurrence as independent ...
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The aim of this study is to prioritize effective factors, landslide susceptibility zonation assessment using maximum entropy (MaxEnt) and dempster shafer models in Doab Samsami watershed of Chaharmahal and Bakhtiari province. For this purpose, 15 factor maps affecting landslide occurrence as independent variables and landslide distribution map as a dependent variable were prepared and weighted using frequency ratio index (FR) and landslide distribution map in the environment ArcGIS® 10.8 . In order to implementation and validation of models, landslide distribution data were randomly divided into two categories of training and test data in the proportion of 70 and 30%, respectively. Maximum Entropy (MAXENT) and Dempster Shaffer models are performed and landslide susceptibility zonation maps are prepared and each model is divided into five very low to very high. In order to evaluate the classification accuracy and validation of the models, the frequency ratio and seed cell area index (FR&SCAI) and the area under receiver characteristic curve (AUC-ROC) were used, respectively. According to the results of the maximum entropy model, annual precipitation factors, lithology, distance to road and drainage land use are important in landslide occurrence, respectively. According to landslide susceptibility zonation maps in both models, more than 50% of landslides occurred in high and very high susceptibility categories. Finally, the validation results of the models showed that the Demester shafer model with AUC-ROC index of 0.95 and classification accuracy with higher FR & SCAI index, greater efficiency and desirability for zoning, modeling and landslide prediction in the study area.
saeedmohammad sabouri; hossein hajialibegi; morteza talebian; morteza fattahi
Abstract
Tectonic activities by the occurrence of earthquakes and the creation of driving force, tectonic uplifts, fissures and fractures caused by faults, creating and seam and cracks in rocks and accelerating the process of mechanical and chemical weathering, creating fault gouges and fault shear as the materials ...
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Tectonic activities by the occurrence of earthquakes and the creation of driving force, tectonic uplifts, fissures and fractures caused by faults, creating and seam and cracks in rocks and accelerating the process of mechanical and chemical weathering, creating fault gouges and fault shear as the materials prone to landslides, increasing the penetration of rocks, changes in the direction and slope of geological layers, etc. cause landslides. The study area is located in the structural zone of Central Alborz and Central Iran between the coordinates of 49.22 to 51.15 east longitude and 35.81 and 36.9 north latitude. In this study, after library surveys and field observations, the location of 280 landslides with fault zones of faults in the region was compared with the relevant software and it was found that 34% of the total landslides identified in Fault zone. Due to the 5% area of fault zones, the high percentage of landslide occurrence indicates the relationship between tectonic activity and landslide occurrence. Therefore, it can be said that tectonic activities have caused landslides in the study area and due to the large number of landslides in the study area, the area can be assessed tectonically with high activity. Vulnerability of residential areas is also high in areas near active and Quaternary faults, because in addition to seismic waves and surface rupture during an earthquake, they threat by another hazard called landslides.
Zakieh Safarpour; Jalil Farzadmehr; Ali Golkarian; Mahdi Bashiri
Abstract
Landslide is one of significant mass movement which causes normous annual human and sesmic region. Therefore, finding hazardous areas for planning and management of them is necessary. So, in this reasearch, occurred landslide in watershed region of bidvaz dam which has area of 161 square kilometers and ...
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Landslide is one of significant mass movement which causes normous annual human and sesmic region. Therefore, finding hazardous areas for planning and management of them is necessary. So, in this reasearch, occurred landslide in watershed region of bidvaz dam which has area of 161 square kilometers and 125 landsliding points are surveyed in different hydrological conditions by index model of slope stability. For specified slopes, graiding test was done and geotechnical parameters were attained. Then, by using Arc view and Arc GIS packages and calibrating parameters in SINMAP and incorporating the geotechnical and hydrological parameters with digital elevation model, SINMAP was conducted. After that, validation was done in two common and high hydrological conditions including rainfalls with a return period of 2-10 years and 20-50 years Respectively. Results showed that the performance of model in simulation of landslides is not appropriate at common hydrological cases. However, increase in hudrological humidity condition, performance of model improves. In calibration and validation, prediction of model increase 21 % and 26 %, respectively. Therefore, utilizing SINMAP model in high hydrological humidity conditions can be useful for choosing dangerous ways according to the landslide map.
