Landslide susceptibility analysis using GIS and artificial neural network     

Saro Lee  Joo‐Hyung Ryu  Kyungduck Min  Joong‐Sun Won 《地球表面变化过程与地形》2003,28(12):1361-1376

The purpose of this study is to develop landslide susceptibility analysis techniques using an arti?cial neural network and to apply the newly developed techniques to the study area of Yongin in Korea. Landslide locations were identi?ed in the study area from interpretation of aerial photographs, ?eld survey data, and a spatial database of the topography, soil type and timber cover. The landslide‐related factors (slope, curvature, soil texture, soil drainage, soil effective thickness, timber age, and timber diameter) were extracted from the spatial database. Using those factors, landslide susceptibility was analysed by arti?cial neural network methods. The landslide susceptibility index was calculated by the back‐propagation method, which is a type of arti?cial neural network method, and the susceptibility map was made with a geographic information system (GIS) program. The results of the landslide susceptibility analysis were veri?ed using landslide location data. The validation results showed satisfactory agreement between the susceptibility map and the existing data on landslide location. A GIS was used to ef?ciently analyse the vast amount of data, and an arti?cial neural network to be an effective tool to maintain precision and accuracy. The results can be used to reduce hazards associated with landslides and to plan land use and construction. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   

A model study on the decay of volcanic aerosol layer and verification with Pinatubo and El Chichon data     

S. Ramachandran  A. Jayaraman  B. R. Sitaram 《Journal of Earth System Science》1997,106(3):157-167

The time evolution of stratospheric aerosol layer formed after a volcanic eruption is studied taking into account the aerosol microphysical processes of growth, coagulation and sedimentation. Using a simple model we could explain the observed evolution of the Pinatubo volcanic layer which decayed in about 3 years. The experimental data obtained by Nd:YAG backscatter lidar over Ahmedabad further supports this finding. The data obtained after the El Chichon volcanic eruption also showed that the El Chichon aerosol layer decayed in about 3 years time. Thus, though the amount of SO₂ injected has been higher, in the case of Pinatubo, about two to three times more than El Chichon, it has resulted in the production of larger aerosol particles due to faster growth and coagulation processes, and subsequently a faster removal rate, to give more or less a similar background aerosol amount at the stratosphere in about 3 years time.  相似文献   

Determination and application of the weights for landslide susceptibility mapping using an artificial neural network   总被引：38，自引：0，他引：38  

Saro Lee  Joo-Hyung Ryu  Joong-Sun Won  Hyuck-Jin Park 《Engineering Geology》2004,71(3-4):289-302

The purpose of this study is the development, application, and assessment of probability and artificial neural network methods for assessing landslide susceptibility in a chosen study area. As the basic analysis tool, a Geographic Information System (GIS) was used for spatial data management and manipulation. Landslide locations and landslide-related factors such as slope, curvature, soil texture, soil drainage, effective thickness, wood type, and wood diameter were used for analyzing landslide susceptibility. A probability method was used for calculating the rating of the relative importance of each factor class to landslide occurrence. For calculating the weight of the relative importance of each factor to landslide occurrence, an artificial neural network method was developed. Using these methods, the landslide susceptibility index (LSI) was calculated using the rating and weight, and a landslide susceptibility map was produced using the index. The results of the landslide susceptibility analysis, with and without weights, were confirmed from comparison with the landslide location data. The comparison result with weighting was better than the results without weighting. The calculated weight and rating can be used to landslide susceptibility mapping.  相似文献   

Probabilistic landslide susceptibility mapping in the Lai Chau province of Vietnam: focus on the relationship between tectonic fractures and landslides   总被引：4，自引：0，他引：4  

Saro Lee  Nguyen Tu Dan 《Environmental Geology》2005,48(6):778-787

This study evaluates the susceptibility of landslides in the Lai Chau province of Vietnam using Geographic Information System (GIS) and remote sensing data to focus on the relationship between tectonic fractures and landslides. Landslide locations were identified from aerial photographs and field surveys. Topographic, geological data and satellite images were collected, processed, and constructed into a spatial database using GIS data and image-processing techniques. A scheme of the tectonic fracturing of crust in the Lai Chau region was established. Lai Chau was identified as a region with many crustal fractures, where the grade of tectonic fracture is closely related to landslide occurrence. The influencing factors of landslide occurrence were: distance from a tectonic fracture, slope, aspect, curvature, soil, and vegetative land cover. Landslide prone areas were analyzed and mapped using the landslide occurrence factors employing the probability–frequency ratio model. The results of the analysis were verified using landslide location data and showed 83.47% prediction accuracy. That emphasized a strong relationship between the susceptibility map and the existing landslide location data. The results of this study can form a basis stable development and land use planning for the region.  相似文献   

Landslide susceptibility modeling based on ANFIS with teaching-learning-based optimization and Satin bowerbird optimizer   总被引：1，自引：0，他引：1  

Wei Chen  Xi Chen  Jianbing Peng  Mahdi Panahi  Saro Lee 《地学前缘(英文版)》2021,12(1):93-107

As threats of landslide hazards have become gradually more severe in recent decades,studies on landslide prevention and mitigation have attracted widespread attention in relevant domains.A hot research topic has been the ability to predict landslide susceptibility,which can be used to design schemes of land exploitation and urban development in mountainous areas.In this study,the teaching-learning-based optimization(TLBO)and satin bowerbird optimizer(SBO)algorithms were applied to optimize the adaptive neuro-fuzzy inference system(ANFIS)model for landslide susceptibility mapping.In the study area,152 landslides were identified and randomly divided into two groups as training(70%)and validation(30%)dataset.Additionally,a total of fifteen landslide influencing factors were selected.The relative importance and weights of various influencing factors were determined using the step-wise weight assessment ratio analysis(SWARA)method.Finally,the comprehensive performance of the two models was validated and compared using various indexes,such as the root mean square error(RMSE),processing time,convergence,and area under receiver operating characteristic curves(AUROC).The results demonstrated that the AUROC values of the ANFIS,ANFIS-TLBO and ANFIS-SBO models with the training data were 0.808,0.785 and 0.755,respectively.In terms of the validation dataset,the ANFISSBO model exhibited a higher AUROC value of 0.781,while the AUROC value of the ANFIS-TLBO and ANFIS models were 0.749 and 0.681,respectively.Moreover,the ANFIS-SBO model showed lower RMSE values for the validation dataset,indicating that the SBO algorithm had a better optimization capability.Meanwhile,the processing time and convergence of the ANFIS-SBO model were far superior to those of the ANFIS-TLBO model.Therefore,both the ensemble models proposed in this paper can generate adequate results,and the ANFIS-SBO model is recommended as the more suitable model for landslide susceptibility assessment in the study area considered due to its excellent accuracy and efficiency.  相似文献   

Aerosol concentrations and size distribution in the troposphere and lower stratosphere over Thumba     

B. H. Subbaraya  A. Jayaraman 《Pure and Applied Geophysics》1982,120(3):407-421

Rocket-borne ultraviolet photometers operating at =0.31 m have been used at Thumba (8°33N, 76°52E) to make measurements of atmospheric scattering at tropospheric and lower stratospheric altitudes. Measurements could be made of the amplitude of the scattered fluxes and the angular distribution up to an altitude of about 24 km on three rocket flights conducted as part of the 16 February 1980 solar eclipse campaign. These measurements have been used to study the size distribution as well as the number densities of aerosols in the troposphere and lower stratosphere over Thumba.  相似文献   

Application and verification of fuzzy algebraic operators to landslide susceptibility mapping   总被引：4，自引：2，他引：4  

Saro Lee 《Environmental Geology》2007,52(4):615-623

The aim of this study was to apply and to verify the use of fuzzy logic to landslide susceptibility mapping in the Gangneung area, Korea, using a geographic information system (GIS). For this aim, in the study, a data-derived model (frequency ratio) and a knowledge-derived model (fuzzy operator) were combined. Landslide locations were identified by changing the detection technique of KOMPSAT-1 images and checked by field studies. For landslide susceptibility mapping, maps of the topography, lineaments, soil, forest, and land cover were extracted from the spatial data sets, and the eight factors influencing landslide occurrence were obtained from the database. Using the factors and the identified landslide, the fuzzy membership values were calculated. Then fuzzy algebraic operators were applied to the fuzzy membership values for landslide susceptibility mapping. Finally, the produced map was verified by comparing with existing landslide locations for calculating prediction accuracy. Among the fuzzy operators, in the case in which the gamma operator (λ = 0.975) showed the best accuracy (84.68%) while the case in which the fuzzy or operator was applied showed the worst accuracy (66.50%).  相似文献   

利用光学遥感数据、GIS及人工神经网络模型分析区域滑坡灾害(英文)   总被引：3，自引：0，他引：3  

Biswajeet Pradhan Saro Lee 《地学前缘》2007,14(6):143-152

用光学遥感数据和地理信息系统(GIS)分析了马来西亚Selangor地区的滑坡灾害。通过遥感图像解译和野外调查,在研究区内确定出滑坡发生区。通过GIS和图像处理,建立了一个集地形、地质和遥感图像等多种信息的空间数据库。滑坡发生的因素主要为:地形坡度、地形方位、地形曲率及与排水设备距离;岩性及与线性构造距离;TM图像解译得到的植被覆盖情况;Landsat图像解译得到的植被指数;降水量。通过建立人工神经网络模型对这些因素进行分析后得到滑坡灾害图:由反向传播训练方法确定每个因素的权重值,然后用该权重值计算出滑坡灾害指数,最后用GIS工具生成滑坡灾害图。用遥感解译和野外观测确定出的滑坡位置资料验证了滑坡灾害图,准确率为82.92%。结果表明推测的滑坡灾害图与滑坡实际发生区域足够吻合。  相似文献   

ESR dating of tooth enamel in Mousterian layer 20, El Castillo,Spain     

Jonathan J. Liberda  Jeroen W. Thompson  W. Jack Rink  Federico Bernaldo de Quirs  Rohit Jayaraman  Kailash Selvaretinam  Kerry Chancellor‐Maddison  Vito Volterra 《Geoarchaeology》2010,25(4):467-474

Nine faunal teeth from layer 20 of El Castillo cave in Cantabrian Spain were dated using electron spin resonance (ESR). Two teeth were rejected due to inconsistent subsample ages, while the remaining teeth yielded a mean age that is consistent with the stratigraphic expectations: 42.7±3.5. Uncertainty in the external γ dose rate results in a potential systematic uncertainty of±6.4ka that should affect all samples equally. The results provide independent confirmation of previously reported ¹⁴C ages for layer 20. © 2010 Wiley Periodicals, Inc.  相似文献   

Adaptation of the Estuarine Fish Fundulus heteroclitus (Atlantic Killifish) to Polychlorinated Biphenyls (PCBs)     

Diane E. Nacci  Denise Champlin  Saro Jayaraman 《Estuaries and Coasts》2010,33(4):853-864

In this study, we describe remarkable intraspecific variation in sensitivity to the broadly distributed pollutants, polychlorinated biphenyls (PCBs), among wild populations of the nonmigratory estuarine Atlantic killifish (Fundulus heteroclitus). Variation among killifish populations was characterized in 28-day laboratory challenges using embryonic and larval life stages and the highly toxic, dioxin-like PCB congener, 3,3′4,4′,5-hexachlorobiphenyl (PCB126). In summarizing results for 24 populations, we show that killifish populations vary over four orders of magnitude in their sensitivity to PCB126 and that this variation is adaptive to the magnitude of contamination at their residence site. The four least-sensitive killifish populations reside in US Atlantic coast urban harbors >100 km apart from one another: New Bedford, MA, Bridgeport, CT, Newark, NJ, and Norfolk, VA, USA. Prior studies examining all but the CT population have shown that these killifish are relatively insensitive to local contaminants, with mixed evidence concerning the heritability of this trait. We show here that tolerance to PCB126 is extreme, with some mechanistic similarities among these four killifish populations. However, these populations do not respond identically to each other, and in at least one population, tolerance appears to degrade over the F1 and F2 generations tested. Complementary ongoing studies using molecular approaches provide opportunity to identify unique and shared mechanisms of tolerance in these independently evolving populations and explore the adaptive benefits and costs of contemporary evolutionary responses in the wild.  相似文献