A hybrid hydrologically complemented warning model for shallow landslides induced by extreme rainfall in Korean Mountain
Ananta Pradhan2016
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Abstract
This study uses a physically based approach to evaluate the factor of safety of the hillslope for different hydrological conditions, in Mt Umyeon, south of Seoul. The hydrological conditions were determined using intensity and duration of whole Korea of known landslide inventory data. Quantile regression statistical method was used to ascertain different probability warning levels on the basis of rainfall thresholds. Physically based models are easily interpreted and have high predictive capabilities but rely on spatially explicit and accurate parameterization, which is commonly not possible. Statistical probabilistic methods can include other causative factors which influence the slope stability such as forest, soil and geology, but rely on good landslide inventories of the site. In this study a hybrid approach has described that combines the physically-based landslide susceptibility for different hydrological conditions. A presence-only based maximum entropy model was used to hybrid and analyze relation of landslide with conditioning factors. About 80% of the landslides were listed among the unstable sites identified in the proposed model, thereby presenting its effectiveness and accuracy in determining unstable areas and areas that require evacuation. These cumulative rainfall thresholds provide a valuable reference to guide disaster prevention authorities in the issuance of warning levels with the ability to reduce losses and save lives.
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2018
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Arabian Journal of Geosciences, 2010
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Landslide Science for a Safer Geoenvironment, 2014
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Journal of Water and Soil Conservation, 2021
Background and Objectives: A review of the damages caused by landslides proves the need to investigate the factors affecting the occurrence of this phenomenon and the need to predict its occurrence. Landslides are one of the most dangerous natural disasters that cause excessive human and financial losses in the mountains worldwide. Due to their dangerous nature, landslides suddenly disrupt the morphology and cause major damage to residential areas, roads, agricultural lands, etc., in mountainous areas. Fortunately, there are appropriate methodologies for assessing risk and determining the effective risk factors associated with them. Materials and Methods: In this study, the maximum entropy of three replications was applied to Maxent software to investigate landslide susceptibility in the southern areas of the Fars Province, Iran. Thirteen factors were used to prepare the landslide susceptibility map: lithological units (Lu), land use/land cover (LULC), slope percentage (SP), slope aspect (SA), altitude, plan curvature (Plan-C), topographic wetness index (TWI), distance to river (DTR), distance to roads (DTRS), distance to fault (DTF), drainage density (DD), normalized difference vegetation index (NDVI), and annual mean rainfall (AMR). In this study, the lack of multicollinearity among the effective factors was proven using tolerance (TOL) and variance inflation factor (VIF) indicators. In addition, the weights of these 13 factors were determined using the analytic hierarchy process (AHP) model. Results: The results of the AHP method show that, in descending order, lithological units, land use-cover, and slope percentage are the most important factors influencing the occurrence of landslides in the study area. Thirty percent of the landslide points were randomly selected, removed from the modeling data, and used for the evaluation using the ROC/AUC indicator. In addition, the final map of the landslide susceptibility was presented in three scenarios using data replication. The preparation of three different outputs had good accuracy, but the third iteration, with an AUC value of 0.778 (ROC= 77.8%), had the highest accuracy in preparing the landslide susceptibility map. The evaluation of landslide susceptibility maps using the second and third iterations, with AUC values of 0.77 (ROC= 77 %) and 0.640 (ROC= 64%), respectively, had good and moderate accuracy with the highest efficiency in predicting landslide sensitivity. Finally, the highest percentage of landslide susceptibility area according to the first, second, and third repetitions were, respectively, in the moderate sensitivity class (0.03-0.1) with the value of 26.14%, in the moderate sensitivity class (0.04-0.4) with a value of 25.91%, and in the moderate sensitivity class (0.04-0.1) with a value of 25.71%, which was the highest percentage of the landslide area. Conclusion: In general, landslides, due to their dangerous nature, suddenly disrupt the morphology of an area and cause major damage that can be measured in the lithological units of the study area, land-use change, and slope percentage. Therefore, landslides are a complex process that has a devastating effect on the environment and human life and requires more investigation and preventive measures.
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Water, 2020
Rainfall induced landslides are creating havoc in hilly areas and have become an important concern for the stakeholders and public. Many approaches have been proposed to derive rainfall thresholds to identify the critical conditions that can initiate landslides. Most of the empirical methods are defined in such a way that it does not depend upon any of the in situ conditions. Soil moisture plays a key role in the initiation of landslides as the pore pressure increase and loss in shear strength of soil result in sliding of soil mass, which in turn are termed as landslides. Hence this study focuses on a Bayesian analysis, to calculate the probability of occurrence of landslides, based on different combinations of severity of rainfall and antecedent soil moisture content. A hydrological model, called Système Hydrologique Européen Transport (SHETRAN) is used for the simulation of soil moisture during the study period and event rainfall-duration (ED) thresholds of various exceedance prob...
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