共查询到19条相似文献，搜索用时 234 毫秒
1.
降雨是诱发滑坡的主要因素之一。目前普遍认为,湿润锋下移导致的土体基质吸力减少是降雨影响滑坡失稳的主要原因,而土壤前期含水率是影响湿润锋下移过程的重要因素之一。基于Green Ampt模型,推导了考虑坡角影响下的滑坡体降雨入渗表达式,同时,结合无限斜坡模型分析了持续稳定的降雨条件下滑坡体稳定性的变化情况,探讨了前期含水率对于降雨过程中浅层滑坡稳定性的影响规律。结果表明:随着降雨的持续进行,浅层滑坡稳定性开始下降较快,之后趋于平缓。前期含水率会影响湿润锋的下移速度,当前期含水率分别为0.32,0.36,0.40时,湿润锋下移速度分别为0.109,0.173,0.42 m/h,说明前期含水率越大,湿润锋下移的速度越快;而前期含水率对于浅层滑坡稳定性的影响主要在降雨初期。 相似文献
2.
通过分析SHALSTAB和TRIGRS等浅层滑坡物理确定性模型存在的问题,提出了基于降雨入渗动态守恒的瞬态降雨
入渗模型,该模型考虑了初期降雨过程、降雨历程以及饱和非饱和入渗过程,证明了SHALSTAB模型是该模型的特殊形式,并克
服了TRIGRS模型参数繁多及一维入渗路径的问题。将无限边坡模型、瞬态降雨入渗模型和GIS进行耦合,研发了可用于大范围
降雨型浅层滑坡危险性预测的集成系统,根据边坡的地质条件、地形参数和降雨特征即可对降雨条件下浅层滑坡的危险性进行评
估。 相似文献
入渗模型,该模型考虑了初期降雨过程、降雨历程以及饱和非饱和入渗过程,证明了SHALSTAB模型是该模型的特殊形式,并克
服了TRIGRS模型参数繁多及一维入渗路径的问题。将无限边坡模型、瞬态降雨入渗模型和GIS进行耦合,研发了可用于大范围
降雨型浅层滑坡危险性预测的集成系统,根据边坡的地质条件、地形参数和降雨特征即可对降雨条件下浅层滑坡的危险性进行评
估。 相似文献
3.
顾及降雨及库水位因素的滑坡时滞分析与预测——以三峡库区新铺滑坡为例 总被引：1，自引：0，他引：1
降雨及库水位涨落是引起库岸滑坡形变失稳的主要诱发因素,但滑坡位移速率对此类诱发因素的响应具有一定的滞后性,影响人类对滑坡所处运动状态的判断与预测。针对常规预测模型中未考虑时滞效应的问题,利用三峡库区新铺滑坡的GNSS位移监测数据、奉节气象站降雨数据以及三峡库区库水位涨落数据,通过对监测区内9个GNSS监测点的位移速率序列与降雨量、库水位高程序列进行时滞互相关分析,确定时滞参数,进而应用多变量灰色系统理论方法,建立了时滞GM(1,3)预测模型,并对滑坡位移速率进行预测验证。结果表明:三峡库区新铺滑坡位移速率与降雨量显著相关,对降雨量的响应滞后时间约为5 d,滑体中后部受降雨影响比前缘更明显;位移速率与库水位高程高度相关,对三峡库区库水位涨落的响应滞后时间约为31 d,滑坡前缘受库水位涨落影响更明显,且离长江越近,滞后时间越短;利用加入时滞参数的时滞GM(1,3)模型进行预测,模型拟合优度达到0.702,相比GM(1,1)模型和未顾及时滞因素的GM(1,3)模型,预测精度分别提升了53.8%和58.3%,平均绝对误差百分比分别降低了7.19%和7.47%,在滑坡位移速率预测及库岸滑坡防灾减灾领域具有一定的工程应用价值。 相似文献
4.
顺层岩质滑坡突发性强, 破坏性大, 是危害山区城镇安全的重要灾害类型之一。发育软弱夹层的顺向斜坡是顺层岩质滑坡的高发区, 区域顺层岩质滑坡易发性评价应融入软弱夹层的控滑机制和空间分布不确定性分析。以万州区铁峰乡为研究区, 在软弱夹层物质结构及空间分布详细调查的基础上, 分析了原生沉积、构造变形和表生改造作用下区内页岩和泥岩两类软弱夹层发展为滑动面的演化机理, 总结了顺层岩质滑坡的变形破坏机理。考虑软弱夹层空间分布的不确定性, 提出了软弱夹层垂向分布和有效控滑深度范围内软弱夹层控滑贡献度的计算模型。提取了软弱夹层类型和控滑贡献度等表征顺层岩质滑坡控滑结构的关键指标, 结合地形地貌、斜坡结构、水文地质及人类工程活动4类要素, 构建了顺层岩质滑坡易发性评价指标体系。针对万州区铁峰乡河谷南侧的顺向坡区段, 以斜坡为评价单元, 采用层次分析法对研究区顺层岩质滑坡开展了易发性评价。结果显示研究区内侏罗系珍珠冲组泥化夹层和自流井组页岩层是顺层岩质滑坡的主要控滑层位, 极高易发区和高易发区占比分别为9.7%和25.8%, 岩质斜坡单元下伏软弱夹层分布情况和斜坡前缘开挖情况是影响滑坡灾害易发性的主要因素, 建房和道路开挖等人类工程活动极易诱发顺层岩质滑坡灾害。与不考虑软弱夹层相关指标的易发性评价结果相比, 本文方法的结果更符合实际情况。 相似文献
5.
陈明明 《大地测量与地球动力学》2024,(2):189-194+208
为有效掌握古滑坡复活特征及其变形规律,基于滑坡区现场调查成果,首先开展其复活变形特征分析,再利用WPT-ROA-RVM-CT模型进行滑坡变形预测研究。结果表明,在强降雨或持续降雨后,滑坡地表裂缝较为发育,具有张剪性质,且滑坡呈明显推移式特征,即滑坡中、后缘变形明显大于前缘,变形方向具有逆时针变化规律,充分说明古滑坡复活变形特征显著。同时,通过变形预测,验证WPT-ROA-RVM-CT模型具有较高的预测精度,并经外推预测,得到滑坡后续变形速率均为正值且较大,判断滑坡后续变形还会进一步增加,具有较大失稳风险,需尽快开展灾害防治研究。 相似文献
6.
基于有限元数值模拟技术,利用GPS数据获取喜马拉雅东构造结区域的断裂运动状态和构造应力场,并结合区域滑坡隐患探讨构造活动对滑坡灾害发育的影响。结果显示,差异化的断裂运动会造成显著相异的构造应力分布,而区域滑坡灾害更集中分布在断层锁固引起的构造应力异常区域;对应力异常区的斜坡进行稳定性研究发现,受应力长期累积影响,斜坡表层应力场持续扰动,造成潜在危险滑移面安全系数降低,促进滑坡失稳。研究表明,断裂构造运动模式可对区域滑坡灾害的发育和分布造成不可忽视的影响,且长期持续的构造应力荷载将促进滑坡灾害的发育。 相似文献
7.
统计确定临界降雨量是滑坡早期预警常用的方法。东南沿海地区台风暴雨不同于一般降雨, 常引发滑坡灾害, 从而威胁沿海地区人民生命财产安全。为了建立台风和非台风降雨型滑坡临界降雨量预测模型, 以浙江丽水市为例, 基于2010-2020年台风暴雨、非台风降雨诱发滑坡与降雨量的统计, 构建了丽水市滑坡发生概率和有效降雨量的关系, 提出了多时长临界降雨量预测模型, 并开展了台风和非台风降雨型滑坡预测模型结果的对比分析。结果表明, 非台风降雨与台风暴雨之间雨型和雨量差异是导致丽水市内2类降雨滑坡预测模型差异的主要原因; 以多时长预测模型确定的临界雨量值法和有效降雨天数更加符合丽水市降雨型滑坡的预测预报, 且预测精度相比于传统相关性分析法更高。研究成果对于开发区域降雨型滑坡预测模型具有理论意义, 对我国东南沿海地区汛期滑坡早期预警具有重要实际意义。 相似文献
8.
强对流或台风等极端天气下乔木坡地发生浅层滑坡灾害往往是暴雨和强风共同作用的结果。以皖南山区一处暴雨型浅层滑坡——畈章组滑坡为例, 通过现场调查和气象资料的分析表明, 除暴雨外风荷载也有可能促进滑坡的启动。为揭示该滑坡启动与破坏后这一完整运动过程的演化机制, 首先基于无限斜坡模型分析了实际降雨条件下的滑坡稳定性, 然后对取自于滑坡体内乔木根系周围和滑动面附近的两种土样利用DPRI型环剪仪, 分别开展了不排水循环剪切试验和自然排水残余剪切试验。结果表明: ①降雨入渗引起滑动面孔隙水压力的上升, 并导致稳定性的降低是畈章组滑坡启动的直接原因; ②乔木根系周围的饱和土在风振作用产生的动剪切荷载下易形成高的超孔隙水压力, 并导致浅表层的局部失稳滑动, 增加了畈章组滑坡整体破坏的可能性; ③滑动面土体的残余强度具有强烈的"正速率效应", 从而控制了畈章组滑坡启动后不会表现出高速远程的运动特征, 与现场调查结论一致。研究结果可以为暴雨协同风振作用下富乔木坡地浅层滑坡的预警预报研究提供参考。 相似文献
9.
确定降雨阈值对于管控降雨型滑坡灾害风险具有重要意义。以浙江衢州市98处降雨型滑坡为例进行降雨阈值研究。在统计分析1970—2019年梅汛期间诱发滑坡降雨特征的基础上,首先对比分析I-D、E-D和E-I曲线建立的降雨阈值模型,然后基于I-D阈值建立以当日降雨量R0和5 d有效降雨量R5为预警指标的滑坡气象预警双指标模型,最后采用历史降雨和滑坡数据检验模型的合理性和可靠性。结果表明：(1)I-D模型对于降雨型滑坡的预测能力优于E-D和E-I模型;(2)按双指标模型反演衢州市历史50 a滑坡气象预警情况,红色、橙色和黄色预警的年均预警次数为1.5,3.2,9.3次,具有较高的合理性;20处验证滑坡点被双指标模型准确预警,其中15处为红色和橙色预警,此外模型成功预警了2014年全部8处降雨型滑坡;(3)用于检验模型预测能力的7处滞后性滑坡全部成功预警,其中3处橙色预警、3处黄色预警和1处蓝色预警。本研究提出的预警模型有助于衢州市滑坡气象预警发布,为政府部门开展风险评价和管理提供新思路与方法。 相似文献
10.
以湖南省澧源镇为例,利用证据权模型和灰色关联度模型分别计算了坡度、地层岩性、斜坡形态、土地利用类型、人类工程活动5个因子二级状态证据权值和一级因子权重;综合2种模型确定全区滑坡易发性指数后,完成基于斜坡单元的全区滑坡易发性区划;根据研究区岩土体类型（碎屑岩类、碳酸盐岩夹碎屑岩类、碳酸盐岩类和松散岩土体类）分组研究不同滑坡发生概率下的有效降雨阈值曲线（I-D曲线）。研究降雨时间为3日、有效强度为22.4 mm/d的降雨工况下各岩土体类型滑坡发生的时间概率。综合时间概率和易发性结果得到澧源镇基于有效降雨阈值的滑坡灾害危险性区划图。研究结果表明:澧源镇滑坡灾害高和极高易发区占研究区总面积的25%,主要沿澧河分布;极高危险区和高危险区占研究区总面积的14%,主要分布在澧河北侧。 相似文献
11.
Yu-Shiu Chen Yu-Shu Kuo Wen-Chi Lai Yuan-Jung Tsai Shin-Ping Lee Kun-Ting Chen Chjeng-Lun Shieh 《山地科学学报》2011,8(4):571-581
Climate change has altered locally single-type disasters to large-scale compound disasters because of increasing intensity
and frequency of extreme rainfall events. The compound disasters can combine small-scale floods, debris flows, shallow landslides,
deep-seated landslides, and landslide lakes into a large-scale single disaster event. Although simulation models and evaluation
tools are available for single-type disasters, no single model is well developed for compound disasters due to the difficulty
of handling the interrelationship between two successive single-type disasters. This study proposes a structure for linking
available single-type simulation models to evaluate compound disasters and provides a useful tool of decision making for warning
and planning of disaster reduction. 相似文献
12.
Chien-Yuan CHEN 《山地科学学报》2012,9(4):463-471
Defining a basin under a critical state(or a self-organized criticality) that has the potential to initiate landslides,debris flows,and subsequent sediment disasters,is a key issue for disaster prevention.The Lushan Hot Spring area in Nantou County,Taiwan,suffered serious sediment disasters after typhoons Sinlaku and Jangmi in 2008,and following Typhoon Morakot in 2009.The basin’s internal slope instability after the typhoons brought rain was examined using the landslide frequency-area distribution.The critical state indices attributed to landslide frequency-area distribution are discussed and the marginally unstable characteristics of the study area indicated.The landslides were interpreted from Spot 5 images before and after disastrous events.The results of the analysis show that the power-law landslide frequency-area curves in the basin for different rainfall-induced events tend to coincide with a single line.The temporal trend of the rainfallinduced landslide frequency-area distribution shows 1/f noise and scale invariance.A trend exists for landslide frequency-area distribution in log-log space for larger landslides controlled by the historical maximum accumulated rainfall brought by typhoons.The unstable state of the basin,including landslides,breached dams,and debris flows,are parts of the basin’s self-organizing processes.The critical state of landslide frequency-area distribution could be estimated by a critical exponent of 1.0.The distribution could be used for future estimation of the potential landslide magnitude for disaster mitigation and to identify the current state of a basin for management. 相似文献
13.
黄冈市是湖北省汛期地质灾害频发区之一, 地质灾害类型以滑坡为主, 其中75%为降雨型滑坡。通过统计分析黄冈市近10年滑坡与降雨的相关关系, 在考虑黄冈市地质灾害易发性分区基础上, 研究黄冈市降雨型滑坡的降雨阈值, 利用逻辑回归模型建立滑坡发生的概率预测模型, 再针对不同等级易发区提出对应的气象预警判据。最后以历史降雨及其滑坡事件检验预警判据的合理性与可信度。结果表明, 所建立的气象预警判据在时间尺度上由以往依托气象部门的中长期预警精细到了24 h的短临预警, 在空间尺度上确定了不同等级易发区的降雨型滑坡气象预警判据。预警准确率大幅提升, 显著提高了黄冈市降雨型滑坡气象预警精度, 可为临灾转移提供精细化的技术指导, 有效降低降雨型滑坡灾害带来的生命财产损失。 相似文献
14.
金沙江结合带结构破碎,软弱岩层发育,流域性特大高位地质灾害频繁发生。针对该区域开展大范围滑坡调查与监测研究,对减灾防灾具有重要意义。以金沙江结合带巴塘段为试验区,采用堆叠InSAR技术分别利用升轨、降轨Sentinel-1A卫星数据对该区域滑坡隐患开展了调查研究。在此基础上,以中心绒乡滑坡群为重点研究区,利用多维小基线子集技术获取了区域二维形变速率(水平东西向和垂直向)及二维时间序列结果。通过对4处典型滑坡体的形变时间序列结果进行分析,发现在两年时间段内安里克米滑坡、仁娘村滑坡、贡伙村滑坡1和贡伙村滑坡2水平方向累积位移量分别达到44.3、-26.6、65.3和-77.1 mm,垂直向累积位移量分别达到-30.2、-88.3、-80.9和-56.9 mm,且这4处滑坡呈现缓慢蠕滑变形趋势。通过对贡伙村滑坡2的形变监测二维时间序列与降雨数据分析发现,强降雨对滑坡变形有一定短暂影响。由于滑坡群处于地质条件脆弱地区,构造活动强烈,在强降雨条件下极易导致滑坡失稳,建议对其进行持续监测,同时该研究成果对流域内其他区域的滑坡调查与监测研究具有参考意义。 相似文献
15.
《山地科学学报》2015,(1)
The "4.20" Lushan earthquake in Sichuan province, China has induced a large amount of geological hazards and produced abundant loose materials which are prone to post-earthquake rainfalltriggered landslides. A detailed landslide inventory was acquired through post-earthquake emergent field investigation and high resolution remote sensing interpretation. The rainfall analysis was conducted using historical rainfall records during the period from 1951 to 2010. Results indicate that the average annual rainfall distribution is heterogeneous and the largest average annual rainfall occurs in Yucheng district. The Stability Index MAPping(SINMAP)model was adopted to assess and analyze the postearthquake slope stability under different rainfall scenarios(light rainfall, moderate rainfall, heavy rainfall, and rainstorm). The model parameters were calibrated to reflect the significant influence of strong earthquakes on geological settings. The slope stability maps triggered by different rainfall scenarios wereproduced at a regional scale. The effect of different rainfall conditions on the slope stability is discussed.The expanding trend of the unstable area was quantitatively assessed with the different critical rainfall intensity. They provide a new insight into the spatial distribution and characteristics of postearthquake rainfall-triggered landslides in the Lushan seismic area. An increase of rainfall intensity results in a significant increase of unstable area. The heterogeneous distribution of slope instability is strongly correlated with the distribution of earthquake intensity in spite of different rainfall conditions. The results suggest that the both seismic intensity and rainfall are two crucial factors for postearthquake slope stability. This study provides important references for landslide prevention and mitigation in the Lushan area after earthquake. 相似文献
16.
Dynamic assessment of rainfall-induced shallow landslide hazard 总被引：1，自引：1，他引：0
The assessment of rainfall-induced shallow landslide hazards is a significant issue in the Three Gorges Reservoir area in China due to the rapid development of land in the past two decades. In this study, a probabilistic analysis method that combines TRIGRS and the point-estimate method for evaluating the hazards of shallow landslides have been proposed under the condition of rainfall over a large area. TRIGRS provides the transient infiltration model to analyze the pore water pressure during a rainfall. The point-estimate method is used to analyze the uncertainty of the soil parameters, which is performed in the geographic information system (GIS). In this paper, we use this method to evaluate the hazards of shallow landslides in Badong County, Three Gorges Reservoir, under two different types of rainfall intensity, and the results are compared with the field investigation. The results showed that the distribution of the hazard map is consistent with the observed landslides. To some extent, the distribution of the hazard map reflects the spatial and temporal distribution of the shallow landslide caused by rainfall. 相似文献
17.
Rudraprayag in Garhwal Himalayan division is one of the most vulnerable districts to landslides in India. Heavy rainfall, steep slope and developmental activities are important factors for the occurrence of landslides in the district. Therefore, specific assessment of landslide susceptibility and its accuracy at regional level is essential for disaster management and proper land use planning. The article evaluates effectiveness of frequency ratio, fuzzy logic and logistic regression models for assessing landslide susceptibility in Rudraprayag district of Uttarakhand state, India. A landslide inventory map was prepared and verified by field data. Fourteen landslide parameters and generated inventory map were utilized to prepare landslide susceptibility maps through frequency ratio, fuzzy logic and logistic regression models. Landslide susceptibility maps generated through these models were classified into very high, high, medium, low and very low categories using natural breaks classification. Receiver operating characteristics (ROC) curve, spatially agreed area approach and seed cell area index (SCAI) method were used to validate the landslide models. Validation results revealed that fuzzy logic model was found to be more effective in assessing landslide susceptibility in the study area. The landslide susceptibility map generated through fuzzy logic model can be best utilized for landslide disaster management and effective land use planning. 相似文献
18.
《山地科学学报》2020,17(7):1565-1580
Landslides induced by prolonged rainfalls are frequent mass movements along the northeastern portion of the Sierra Madre Oriental in Mexico, causing significant damage to infrastructure. In this work, we have studied the connection between rainfall and landslides in the Santa Rosa Canyon, a catchment located in the northeastern Mexico. A landslide database triggered by major storms and hurricanes that have hit the region over the past 30 years was analyzed. A total of 92 rainfall events in the Santa Rosa Canyon were studied to determine the amount of precipitation needed to trigger shallow landslides. For each event the duration(D, in hours) and the cumulated rainfall event(E, in mm) were determined by using historical rainfall data from weather stations located near the study area. We have proposed an ED threshold for rainfall-induced landslides with durations 0.5 D 120 hours to address the conditions that trigger these events in the study area. On analyzing the obtained threshold, it has been established that almost 60 mm of a daily rainfall accumulation is required to trigger shallow landslides in the study area. This estimation is consistent with other calculations made for areas close to the Santa Rosa Canyon. Finally, we validated the predictive capability of the threshold with a different set of rainfall data that did not result in landslides performing a straightforward receiver operating characteristic analysis. A good approach was obtained, especially for rainfall events with daily measurements. Results could be used as input information in the design of a landslide early warning system for the northeastern Mexico, and replicated for other landslide prone areas in the region. 相似文献
19.
我国是世界上滑坡灾害最严重的国家之一, 重大滑坡灾害严重威胁人民生命财产安全和国家重大战略实施。滑坡精准预测预报是防灾减灾的前提, 也是亟待突破的世界性科学难题。以重大滑坡预测预报为目标, 聚焦滑坡演化过程与物理力学机制核心科学问题, 凝炼了滑坡启滑关联机制、滑坡启滑物理力学机制、滑坡过程预测预报理论3个关键科学问题, 提出了如下研究思路: 以系统论、控制论和信息论为指导, 依托大型野外试验场, 采用现场原型试验与多场关联监测、大型物理模型试验、多场耦合模拟等技术手段, 以滑坡孕育过程为基础, 提出了重大滑坡的启滑分类; 揭示锁固解锁型、静态液化型和动水驱动型滑坡启滑物理力学机制, 建立相应的启滑判据; 构建重大滑坡数值预报模式与实时预报平台, 创立基于物理力学过程的滑坡预测预报理论。通过实施, 可奠定上述3类滑坡预测预报的地质、力学与物理基础, 引领重大滑坡预测预报研究, 保障国家重大战略的顺利实施, 契合国家防灾减灾重大需求。 相似文献