共查询到17条相似文献，搜索用时 512 毫秒
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选择地貌特征（包括地形坡度、沟谷切割状况、洼地封闭状况、前缘临空状况）、滑面特征（包括滑面倾角、滑面形态、滑面阻抗比）、滑体结构和近期活动迹象4大类9个因子作为古（老）滑坡类潜在滑坡的判识指标,以三峡库区和岷江上游地区相同数量的典型滑坡作为学习样本,依据距离判别分析（DDA）和Fisher线性判别分析（FLDA）方法,分别建立了两个研究区潜在滑坡的DDA判识模型和FLDA判识模型。实例分析结果表明,DDA方法对两个研究区学习样本和测试样本的误判率均为0,而FLDA方法对两个研究区测试样本的误判率分别为5.56%和11.11%,对学习样本的错判率分别为11.1%和0%。因此,在三峡库区和岷江上游地区潜在滑坡的判识中,DDA法比FLDA法判识准确性更高、适用性更强。 相似文献
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灰色关联度法和距离判别分析法在溪洛渡库区潜在滑坡判识中的应用 总被引：1，自引：0，他引：1
以溪洛渡库区深入研究的14个典型滑坡为研究对象,在初步建立潜在滑坡判识指标的基础上,运用灰色关联度理论优选确定了影响库区潜在滑坡孕育的8个关键主控因素:坡面平均坡度、滑体内冲沟切割程度、洼地封闭状况(或排水条件)、滑面平均倾角、滑面形态、下滑段长度与总滑面长度之比、滑体结构及近期活动迹象,并依据距离判别分析的理论和方法,建立了溪洛渡库区潜在滑坡的距离判识模型。该判识模型对库区5个待判滑坡样本和9个滑坡学习样本的判识准确率均达到了100%。 相似文献
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如何准确地判识和评价滑坡的稳定性一直是滑坡研究中的关键问题。基于多分类支持向量机的基本理论,利用三峡库区的37个典型滑坡（27个训练样本,10个测试样本）,建立了滑坡稳定性判识的多分类支持向量机模型,并与距离判别分析方法进行了比较。结果表明,SVM模型对测试样本和训练样本的判识准确率均达到100％,而距离判别法对测试样本和训练样本的判识准确率分别为80％和77.8％,前者的判识精度明显优于后者。在此基础上,将SVM模型运用于溪洛渡库区牛滚凼滑坡的稳定性判识中,结果与实际情况吻合较好。 相似文献
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缺氧环境及地球化学判识标志的探讨--以鄂尔多斯盆地为例 总被引：33，自引：3，他引：30
在地质历史时期,古缺氧环境对沉积有机质的数量和质量都具有重要意义.对于优质烃源岩而言较高的有机质数量、较好的有机质质量无疑是主要条件.在综合国内外研究成果的基础上,结合鄂尔多斯盆地奥陶系碳酸盐岩的微量元素和有机质丰度等的研究,着重讨论了微量元素、稳定同位素和有机质等判识缺氧环境的地球化学指标情况,并建立了缺氧环境基本特征及判识指标的综合体系.缺氧沉积中一般为V、Mo、Zn等金属和有机碳富集程度高,DOP＞0.40,V/(V Ni)＞0.45,U/Th＞0.75,δCe＞-0.1,Pr/Ph＜1.研究表明,地球化学-沉积学的综合指标能更有效地判识和反演古缺氧环境. 相似文献
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滑坡的演化一般要经历初始变形、等速变形和加速变形3个阶段,准确地划分这3个阶段是进行滑坡预测预报的基础。依据大量滑坡从初始变形到失稳破坏的监测数据,采用数据挖掘中的关联规则,用经典的Apriori算法挖掘滑坡变形过程中累积位移、累积加速度等属性与演化阶段的关联关系,发现滑坡演化规律与累积加速度变化特征关联性强,在滑坡从初始变形进入等速变形,以及从等速变形到加速变形阶段时,都存在相应的阈值,即累积加速度在滑坡进入等速和加速变形阶段前后呈现出不同的特点。针对此特点,以湖北秭归县鸡鸣寺滑坡为例,将累积加速度作为划分鸡鸣寺滑坡演化阶段的指标,得出划分阈值,并利用关联规则分析其相关性。最后将此指标用于其他滑坡,均得到良好效果。因此根据该指标,可望实现滑坡演化阶段的自动判识。 相似文献
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结合沪瑞国道主干线贵州境镇胜高速公路十八合同段晴隆滑坡深部位移监测曲线特征,总结归纳了滑坡深部累积位移曲线“V”型、“B”型、“r”型、“钟摆”型及“复合”型等几种,详细论述了常见的曲线特征类型及其研究意义,提出了依据滑坡深部位移监测成果资料判别滑坡动态变形特征及其稳定性的判识方法。 相似文献
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水力封堵型煤层气藏判识条件分析 总被引：1，自引：0，他引：1
从宏观和微观两个方面分析了不同条件下煤层气的赋存特征,总结出水力封堵型煤层气藏的判识条件。研究表明,宏观上,可以通过煤储层边界的物理性质进行判识,在煤储层与地下水连通的基础上,分析断层、岩性、地下水三者之间的组合对水力封堵型煤层气藏赋存所起的作用,将水力封堵型煤层气藏划分为地层-水力封堵型、开放性断层-水力封堵型、封闭性断层-水力封堵型、岩性-水力封堵型、开放性断层-岩性-水力封堵型五种类型;微观上,主要通过煤储层流体的化学性质来判识,包括水的矿化度、水化学类型、甲烷碳同位素等三个方面,通常水力封堵型煤层气藏的地层水矿化度低于1 000mg/L,甲烷碳同位素较轻,且水化学类型为NaHCO3型、Na2SO4型或为NaHCO3和Na2SO4混合型。 相似文献
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青藏高原东缘是全球古滑坡最发育的地区之一。基于大量地面调查、遥感解译和年龄测试资料,总结了青藏高原东缘深切河谷区古滑坡的判识方法、主要发育特征、形成时代和分布规律。结果表明,古滑坡具有规模巨大、高位起动、物质组成和结构复杂等特征,其空间分布与地形地貌、岩性组合和活动构造等因素关系密切。古滑坡在区域上受气候变化影响较明显,一般形成于河流强烈下切阶段,与河流阶地具有较好的对应关系,多数已发现的古滑坡与T2阶地时代相当,时间跨度为40~10 ka,集中分布于30~20 ka。构造活动和地震造成古滑坡在不同区段的分布具有差异性,一般在活动断裂带附近密集发育,现今发现的古滑坡多为这种成因。这些认识对于科学认知古滑坡的形成演化过程和未来巨灾风险预测具有重要的指导作用。 相似文献
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Global climate change has increased the frequency of abnormally high rainfall; such high rainfall events in recent years have occurred in the mountainous areas of Taiwan. This study identifies historical earthquake- and typhoon-induced landslide dam formations in Taiwan along with the geomorphic characteristics of the landslides. Two separate groups of landslides are examined which are classified as those that were dammed by river water and those that were not. Our methodology applies spatial analysis using geographic information system (GIS) and models the geomorphic features with 20?×?20 m digital terrain mapping. The Spot 6 satellite images after Typhoon Morakot were used for an interpretation of the landslide areas. The multivariate statistical analysis is also used to find which major factors contribute to the formation of a landslide dam. The objective is to identify the possible locations of landslide dams by the geomorphic features of landslide-prone slopes. The selected nine geomorphic features include landslide area, slope, aspect, length, width, elevation change, runout distance, average landslide elevation, and river width. Our four geomorphic indexes include stream power, form factor, topographic wetness, and elevation–relief ratio. The features of the 28 river-damming landslides and of the 59 non-damming landslides are used for multivariate statistical analysis by Fisher discriminant analysis and logistic regression analysis. The principal component analysis screened out eleven major geomorphic features for landslide area, slope, aspect, elevation change, length, width, runout distance, average elevation, form factor, river width, stream power, and topography wetness. Results show that the correctness by Fisher discriminant analysis was 68.0 % and was 70.8 % by logistic regression analysis. This study suggests that using logistic regression analysis as the assessment model for identifying the potential location of a landslide dam is beneficial. Landslide threshold equations applying the geomorphic features of slope angle, angle of landslide elevation change, and river width (H L/W R) to identify the potential formation of natural dams are proposed for analysis. Disaster prevention and mitigation measures are enhanced when the locations of potential landslide dams are identified; further, in order to benefit such measures, dam volume estimates responsible for breaches are key. 相似文献
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焦作矿区地下水水化学特征及涌水水源判别的FDA模型 总被引：2，自引：0，他引：2
运用统计学Fisher判别分析(FDA)理论,根据含水层涌水水样的水化学分析结果,建立焦作矿区涌水水源的数学识别模型,分析了矿区地下水水化学特征及形成机制,确定了含水层涌水的补给来源,并对它们进行判别分析及结果验证。结果表明:FDA模型预测涌水水源与常规水化学方法分析结果基本一致;矿区奥灰水补给太灰水特征明显,煤层顶板砂岩水与深部岩溶水联系较弱。FDA模型利用回代估计法所得到的误判率小,适用性强,简易方便,具有较强的涌水水源判别能力。 相似文献
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Rainfall is the most relevant factor for the triggering of landslides and it is characterized by an extreme variability. Rainfall analysis is the most frequently adopted approach for predicting landslides. But predicting deep-seated landslides by means of rainfall thresholds is sometimes inadequate due to the complexity of such slopes. In this paper, further study of the loading / unloading response ratio theory applied in landslides prediction was carried out. As the aforementioned effect and character of rainfall was concerned, a prediction for the known Xintan landslide was carried out by means of the loading / unloading response ratio method, in which the action of water was regarded as loading/unloading measures. The results show that it is an effective method for landslides prediction, and it has an advantage over conventional rainfall thresholds or time sequences analysis method. 相似文献
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基于GIS的小江断裂中北段滑坡灾害危险性评价 总被引：1，自引：0，他引：1
小江断裂中北段作为金沙江下游重大水电工程库区内最重要的活动断裂构造,其沿线滑坡地质灾害发育,严重制约了当地的经济和社会发展。在详细调查了小江断裂中北段沿线滑坡地质灾害的基础上,选取了坡度、坡向、工程地质岩组、岸坡结构、断裂构造等9个影响因子作为评价指标,对研究区滑坡灾害的发育分布规律进行了分析研究,并采用AHP-CF法建立了滑坡灾害危险性评价模型,利用GIS空间分析功能得出了研究区滑坡地质灾害危险性分区。通过检验曲线验证滑坡地质危险性评价结果可知,AUC值为80%。 相似文献
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Assessing the hazard of potential landslides is crucial for developing mitigation strategies for landslide disasters. However, accurate assessment of landslide hazard is limited by the lack of landslide inventory maps and difficulty in determining landslide run-out distance. To address these issues, this study developed a novel method combining the InSAR technique with a depth-integrated model. Within this new framework, potential landslides are identified through InSAR and their potential impact areas are subsequently estimated using the depth-integrated model. To evaluate its capability, the proposed method was applied to a landslide event that occurred on November 3, 2018 in Baige village, Tibet, China. The simulated results show that the area with a probability of more than 50% to be affected by landslides matched the real trimlines of the landslide and that the accuracy of the proposed method reached 85.65%. Furthermore, the main deposit characteristics, such as the location of maximum deposit thickness and the main deposit area, could be captured by the proposed method. Potential landslides in the Baige region were also identified and evaluated. The results indicate that in the event of landslides, the collapsed mass has a high probability to block the Jinsha River. It is therefore necessary to implement field monitoring and prepare hazard mitigation strategies in advance. This study provides new insights for regional-scale landslide hazard management and further contributes to the implementation of landslide risk assessment and reduction activities.
相似文献16.
岩体质量等级分类在实际的工程中有着很重要的作用。基于主成分分析（PCA）法和与Fisher判别分析法相结合建立岩体质量等级判别模型,选取单轴抗压强度、岩体体积节理数、声波纵波速度、节理面风化变异系数、节理面粗糙度系数和透水性系数6种指标作为岩体质量分级判别的判别因子。以永平铜矿露天矿区工程岩体特征资料中的20个样本为训练样本,10个为待判样本,对该模型进行检验和应用,并与传统的RMR法、Fisher判别分析模型的结果进行比较,相应正确率分别为87%、70%、77%,判断结果表明利用主成分分析法和Fisher判别分析法建立的模型判别能力更高。 相似文献
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2010年玉树7.1级地震造成了一系列次生地质灾害。笔者在玉树灾区地震地质灾害调查基础上,结合Quickbird高分辨率遥感影像数据和航片影像数据,以目视解译为主,共提取了542处地震滑坡,并首次发现了11处古地震滑坡。调查研究结果显示,玉树地震滑坡主要包括崩塌、狭义的滑坡和土溜等三种类型。其中地震崩塌占到了90%以上,按其物质成分可进一步划分为碎屑型崩塌、碎屑流型崩塌和岩崩等三类。地震滑坡的空间展布特征显示,该区80%以上的地震滑坡集中分布在以玉树活动断层为轴的长约95km、两侧宽2km的廊带区内,并与发震断层距离和宏观震中有很好的相关性,其高密度区与同震地表破裂的空间分段性也有很好的对应关系,体现出典型的走滑型发震断层的控灾特点。同时,还进一步分析了山体坡度、坡体形态、临空面高度和地层岩石与岩体完整度等因素对地震滑坡总体分布的影响。对古地震滑坡的初步研究发现,古地震滑坡的规模、期次和分布特征间接地反映出玉树断裂带在全新世期间曾发生过多次震级强度明显大于本次玉树7.1级地震的古地震事件,这为更深入探索玉树断裂带古地震事件提供了另一种重要的研究途径。此外,地震滑坡分布与地表破裂和极震区破坏程度之间的密切空间关系指示,地震滑坡也可以成为快速圈定宏观震中以及开展极震区地震烈度评价等方面的重要指标。 相似文献