共查询到18条相似文献，搜索用时 140 毫秒
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以2010年福建省顺昌地区滑坡资料为基础数据,采用随机森林模型对福建顺昌地区山体滑坡发生与滑坡因子之间的关系进行实证分析,通过ROC曲线和Kappa系数,探讨了随机森林模型在我国南方山体滑坡空间预测中的适应性,同时结合平均准确率降低度和平均基尼指数降低度,分析了不同滑坡因子的重要性程度及其影响规律.研究结果表明:5个样本组建立的随机森林模型均有统计学意义,5个样本模型的滑坡总预判精度为86.88%~93.00%;随机森林模型制作的研究区滑坡危险性空间预测图与实际的滑坡分布情况基本吻合;归一化植被指数、滑坡发生当天降雨量、平面曲率是滑坡形成的主要原因,特殊的地形地貌和植被指数是滑坡形成的内因,而短时间的强降雨是滑坡形成的外因.研究结果说明随机森林模型适用于滑坡空间预测工作,具有良好的建模效果,可在相关研究工作中加以推广和应用. 相似文献
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利用滑坡灾害普查资料和气象资料,结合地理信息系统(GIS)和降雨推算模型进行空间分析,对庆元县滑坡与降雨作相关研究后发现:降雨具有诱导和直接触发滑坡的综合作用效果;庆元县滑坡的时空分布,受降雨地区和降雨时间的控制,并与一定的地质条件及人类活动有关;滑坡剧烈活动时间与降雨时间及暴雨、大暴雨频次吻合或略滞后,庆元县滑坡的起动降雨量为:日降雨量≥50 mm或滑坡前10 d累积降雨量≥100 mm. 相似文献
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滑坡是影响管道完整性的重要因素之一。基于土弹簧模型建立了滑坡管道有限元分析模型,考虑了管土之间相互作用的非线性特征,研究了管道内压、滑坡长度、滑坡位移、滑坡方向与管道轴向的夹角等因素对管道应力的影响。以陕京输气管道为例,分析了不同管道工况下滑坡相关因素对管道应力的影响,量化分析了垂直管道轴向的横向滑坡和平行管道轴向的纵向滑坡两种情况下的力学影响因素,得出滑坡方向与管道轴线的夹角对滑坡产生的附加应力具有重要影响,对于管道线路的完整性管理具有重要意义。研究结果可为滑坡地区管道的风险控制提供理论依据和技术参考。（图6,表1,参]5） 相似文献
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以陕南地区28个市(县、区)的地质灾害详细调查成果为基础,统计了区内3213处堆积层滑坡,并选取典型堆积层滑坡进行了野外调查,研究区内堆积层滑坡发育规律.结果表明:堆积层滑坡空间分布受地层岩性、地貌、地质构造、降雨及人类工程活动控制.发生时间与区内降雨时间一致,主要集中分布于每年6—10月;区内堆积层滑坡主要为小型、浅层堆积层滑坡.滑动面位置主要为土-岩接触面,倾角为20°～40°,滑体物质主要为碎石土,滑带物质主要为残坡积土,细粒含量高,遇水饱和后强度极低.该研究结果为区内堆积层滑坡的防灾减灾工作提供一定的理论支持. 相似文献
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南充市强降雨诱发地质灾害风险预警技术研究 总被引：1，自引：0，他引：1
南充市是四川省地质灾害隐患点分布较多的地区之一,且90%以上为滑坡类型。因此,探索雨量与滑坡的关系,进行提前预警,为临灾转移提供充裕时间,有效降低滑坡灾害带来的生命财产损失显得尤为重要。本文基于南充市2011—2016年181条强降雨型滑坡记录,与213个自动区域站的小时雨量数据进行对比,分析滑坡成因,应用平均降雨强度(I)-时间窗口(D)关系阈值方法,确定了分县域引发滑坡的I-D关系阈值。提出南充市强降雨诱发滑坡地质灾害风险预警技术流程框架和关键性阈值参考值,为地质灾害的准确及时预警奠定了基础。 相似文献
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滑坡的成因机制及稳定性评价对工程和人类活动至关重要,在对云南省陇川县新建通用机场的勘察过程中发现中型不稳定老滑坡,该滑坡对拟建的重要工程安全性产生严重的影响。通过钻探、物探、遥感等手段对该滑坡进行详细勘察,发现海岗滑坡为该地区(半成岩地层)的典型滑坡,即以流水快速侵蚀,切入坡内,形成深大冲沟,然后以冲沟为临空面,发生第1次滑动,在后期强降雨诱发下以自然边坡为临空面发生第2次滑动。在地貌上表现为"肚大口小",似瓢状,命名为"瓢把子"滑坡。该类滑坡滑带区别于一般的土质或岩质滑坡,滑带为后部高陡、中部圆滑、前部平缓的折线型。通过FLAC3D计算分析滑坡稳定性表明,在地震作用下滑坡计算剖面最大位移量为12.3mm,与天然工况相比增大了7.32倍;降雨作用下滑坡剪应变集中区主要分布在斜坡堆积体与滑床接触带附近,剪应变增大了6.25倍,充分证明该类滑坡在降雨及地震作用下极不稳定。 相似文献
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面对当前经济发展的时代背景,林业的破坏不仅引发了山洪、泥石流等地质灾害,同时还阻碍了我国社会的进步及经济的发展。在现有的基础上针对林业当前的发展形势以及今后的发展趋势,做以下论述。 相似文献
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Real-time landslide warning during heavy rainfall 总被引：7，自引：0，他引：7
Keefer DK Wilson RC Mark RK Brabb EE Brown WM Ellen SD Harp EL Wieczorek GF Alger CS Zatkin RS 《Science (New York, N.Y.)》1987,238(4829):921-925
A real-time system for issuing warnings of landslides during major storms is being developed for the San Francisco Bay region, California. The system is based on empirical and theoretical relations between rainfall and landslide initiation, geologic determination of areas susceptible to landslides, real-time monitoring of a regional network of telemetering rain gages, and National Weather Service precipitation forecasts. This system was used to issue warnings during the storms of 12 to 21 February 1986, which produced 800 millimeters of rainfall in the region. Although analysis after the storms suggests that modifications and additional development are needed, the system successfully predicted the times of major landslide events. It could be used as a prototype for systems in other landslide-prone regions. 相似文献
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详细介绍了雨季使用的无电力双保险自动报警装置的理论根据、装置组成及其工作过程,对保护山区坡地村民的生命财产安全具有现实意义。 相似文献
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High-resolution interferometric synthetic aperture radar (InSAR) permanent scatterer data allow us to resolve the rates and variations in the rates of slow-moving landslides. Satellite-to-ground distances (range changes) on landslides increase at rates of 5 to 7 millimeters per year, indicating average downslope sliding velocities from 27 to 38 millimeters per year. Time-series analysis shows that displacement occurs mainly during the high-precipitation season; during the 1997-1998 El Ni?o event, rates of range change increased to as much as 11 millimeters per year. The observed nonlinear relationship of creep and precipitation rates suggests that increased pore fluid pressures within the shallow subsurface may initiate and accelerate these features. Changes in the slope of a hill resulting from increases in the pore pressure and lithostatic stress gradients may then lead to landslides. 相似文献
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Hewitt K 《Science (New York, N.Y.)》1988,242(4875):64-67
In July 1986, three catastrophic landslides deposited about 20 x 10(6) cubic meters of debris on Bualtar Glacier in the Karakoram Himalaya. A sudden acceleration and superficial breakup of the glacier provided an opportunity to examine the fresh deposits in depth. Beneath a surface layer of large boulders, finer materials, mainly sand and silt, made up half of the total volume. The fine materials were formed during the rock avalanche from mostly intact, massive rock of the source zone. Velocity estimates suggest that this disaggregation occurred in less than 2 minutes. Coarse materials remained in bands of uniform lithology, but the fine materials had diffused throughout the landslides. A small amount of carbonate appears to have been calcined by frictional heating, presumably at the base of the initial sliding masses. These observations are relevant to understanding the mechanisms of catastrophic landslides. Other nearby rock avalanche deposits indicate that landslides are an important geomorphic process in the area and that they pose a continuing risk to human activity. 相似文献
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Acute sensitivity of landslide rates to initial soil porosity 总被引：2，自引：0，他引：2
Iverson RM Reid ME Iverson NR LaHusen RG Logan M Mann JE Brien DL 《Science (New York, N.Y.)》2000,290(5491):513-516
Some landslides move imperceptibly downslope, whereas others accelerate catastrophically. Experimental landslides triggered by rising pore water pressure moved at sharply contrasting rates due to small differences in initial porosity. Wet sandy soil with porosity of about 0.5 contracted during slope failure, partially liquefied, and accelerated within 1 second to speeds over 1 meter per second. The same soil with porosity of about 0.4 dilated during failure and slipped episodically at rates averaging 0.002 meter per second. Repeated slip episodes were induced by gradually rising pore water pressure and were arrested by pore dilation and attendant pore pressure decline. 相似文献
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2022年9月5日,四川省甘孜藏族自治州(简称甘孜州)泸定县发生6.8级地震,此次地震造成了周边区域水土流失加剧,生态状况急剧恶化。因此,本研究以受“9.5”泸定地震影响产生山体滑坡的林地作为研究对象,以附近未受地震影响的、林分结构相近的林地作为对照,分析地震对林地土壤物理性质及其碳储量的影响。结果表明,0-5和5-10cm土层均表现为滑坡后土壤的孔隙度、毛管持水量均低于未滑坡土壤,容重、非毛管孔隙度高于未滑坡土壤,碳储量则低于未滑坡土壤。综上所述,地震产生的滑坡会对土壤的物理结构产生影响,进而减少土壤的有机碳储量。 相似文献