The mountainous region of Greater Sochi, including the Olympic ski-jump complex area, located in the northern Caucasus, is always subjected to landslides. The weathered mudstone of low strength and potential high-intensity earthquakes are considered as the crucial factors causing slope instability in the ski-jump complex area. This study aims to conduct a seismic slope instability map of the area. A slope map was derived from a digital elevation model (DEM) and calculated using ArcGIS. The numerical modelling of slope stability with various slope angles was conducted using Geostudio. The Spencer method was applied to calculate the slope safety factors (Fs). The pseudostatic analysis was used to compute Fs considering seismic effect. A good correlation between Fs and slope angle was found. Combining these data, sets slope instability maps were achieved. Newmark displacement maps were also drawn according to empirical regression equations. The result shows that the static safety factor map corresponds to the existing slope instability locations in a shallow landslide inventory map. The seismic safety factor maps and Newmark displacement maps may be applied to predict potential landslides of the study area in the case of earthquake occurrence.

Link for citation: Van B. Duong, Fomenko I.K., Trung K. Nguyen, ThiHong L. Vi, Zerkal O.V., Hong D. Vu. Application of GIS-based bivariate statistical methods for landslide potential assessment in Sapa, Vietnam. Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2022, vol. 333, no. 4, рр. 126-140. In Rus. The relevance. Predicting and minimizing the impact of natural disasters are critical tasks for governments worldwide, including Vietnam. Landslides are one of the most frequent types of natural disasters in Vietnam, especially in the northern mountainous provinces, resulting in significant loss of life and property. In this study, the GIS-based bivariate statistical methods were applied for assessing landslide potential in Sapa district, Laocai province, Vietnam. For assessing landslide susceptibility, nine landslide-related factors were selected, including elevation, distance to roads, slope, distance to faults, average monthly precipitation, relative relief, land use, crust weathering, and distance to drainage. The main aim of this study is to prepare landslide potential maps for the study area. In addition, the study also demonstrated the effectiveness of bivariate statistical methods for landslide susceptibility assessment. Object of the study is the landslide susceptibility in Sapa district, Laocai province, Vietnam. Methods: GIS-based bivariate statistical methods including frequency ratio, landslide susceptibility analysis, and statistical index. Results. Landslide potential maps were prepared using GIS-based bivariate statistical methods. The study area is divided into five landslide potential zones: very low, low, moderate, high, and very high. The area under the curve of the receiver operating characteristic (AUCROC) was used to evaluate the performance of these models. The success rates of the models for the training data are 74,60 % frequency ratio, 70,82 % landslide susceptibility analysis and 76,36 % statistical index. The prediction rates of the models for the testing data are 77,01 % frequency ratio, 74,36 % landslide susceptibility analysis and 78,11 % statistical index. The performance evaluation of the models revealed that all three techniques are efficient in assessing landslide potential in the study area. Study results are critical for land use planning and economic development, as well as minimizing landslide-related damage. Ссылка для цитирования: Применение статистических методов на основе ГИС для оценки потенциального развития оползней в районе Шапа, Вьетнам / Зыонг Ван Бинь, И.К. Фоменко, Нгуен Чунг Киен, Ви Тхи Хонг Лиен, О.В. Зеркаль, Ву Хонг Данг // Известия Томского политехнического университета. Инжиниринг георесурсов. – 2022. – Т. 333. – № 4. – С. 126-140. Актуальность. Прогнозирование и минимизация последствий стихийных бедствий являются важнейшими задачами для правительств во всем мире, включая Вьетнам. Оползни являются одним из наиболее распространенных видов стихийных бедствий во Вьетнаме, особенно в северных горных провинциях, что приводит к значительным человеческим жертвам и материальному ущербу. В этом исследовании для оценки потенциального развития оползней в районе Шапа, провинция Лаокай, применялись статистические методы, с использованием геоинформационных систем (ГИС). Для решения поставленной задачи было отобрано девять факторов, определяющих оползневую восприимчивость на рассматриваемой территории: высота над уровнем моря, расстояние до дорог, крутизна склонов, расстояние от разломов, среднемесячное количество осадков, вертикальное расчленение рельефа, землепользование, тип коры выветривания и расстояние до эрозионной сети. Основная цель исследования заключается в подготовке карт потенциального развития оползней для района Шапа. Кроме того, выполненные работы продемонстрировали эффективность использованных статистических методов при оценке восприимчивости территории к оползневому процессу. Объектом исследования является оползневая восприимчивость в районе Шапа провинции Лаокай (Вьетнам). Методы: статистические методы с использованием ГИС, включая метод соотношения частотностей (англ. Frequency Ratio method – FR), метод анализа оползневой восприимчивости (англ. Landslide Susceptibility Analysis method – LSA) и метод статистического индекса (англ. Statistical Index method – SI). Результаты. Были построены для исследуемой территории, которая была разделена...

ПРИМЕНЕНИЕ ВЕРОЯТНОСТНОГО АНАЛИЗА ПРИ КОЛИЧЕСТВЕННОЙ ОЦЕНКЕ УСТОЙЧИВОСТИ СКЛОНА

The northern mountainous region of Vietnam is particularly susceptible to sediment-related disasters, such as landslides, during the rainy season. This paper presents slope stability modeling results for a landslide event triggered by heavy rainfall in Trung Chai commune, Sapa, Vietnam. Stability simulations were conducted using input data, including 1-m DEM, the distribution and characteristics of slope materials, and the change of pore pressure ratio. The behavior of slopes under the impact of rainfall was analyzed using the limit equilibrium method and the finite element method, which are integrated into the programs of Rocscience Inc. In addition, since the Trung Chai commune is located in a seismically active region, single earthquakes or the combination of earthquakes and rainfall may trigger landslides. As a result, the study determined the relationship between seismic loading and pore water pressure for the studied slope. The study results showed that both limit equilibrium and the finite element methods have high efficacy in modeling slope stability in this study. Therefore, this study recommended that these methods may be employed for slope stability studies in other regions of Vietnam or other regions of the world with similar geological conditions.