北京市延庆区石窑村南地沟泥石流特征及发展趋势预测

本文以北京市延庆区石窑村南地沟泥石流为研究对象,通过野外调查与GIS统计分析,研究该流域降雨条件、地形地貌和沟道条件、物源条件等形成条件特征,针对流域内松散堆积物转换,开展了流域分区特征分析;通过14个因子分析,建立了该泥石流的发育阶段识别模型,对其发展趋势进行了预测;利用单沟泥石流堆积区公式开展了最大危险区预测研究,提出相应的防治措施建议。研究表明:石窑村南地沟泥石流内松散堆积物动储量达18.36×10~4 m~3,物源类型划分为冲洪积物源、残坡积物源、人工堆积物源和崩滑塌物源4种,其中残坡积所占比重最大。该泥石流属于暴雨-沟谷型-支沟群发型、中易发泥石流,泥石流发展阶段处于发育期,最大危险区面积为0.413 km~2,对沟口堆积区的石窑村及村民的生命财产安全造成威胁,建议采用局部物源平整与疏理排导渠相结合的综合治理措施。本文为该区地质灾害防治提供基础依据。     

北京市延庆地区水泉沟村车道沟泥石流发育特征及动力学研究

本文以北京市延庆地区水泉沟村车道沟泥石流沟为研究对象,通过泥石流精细调查及资料统计,研究该泥石流发育特征和形成条件,在分析流域内松散堆积物补给特征的基础上,综合研究了该泥石流的动力学特征,进而开展泥石流危险区预测评价,提出相应的防治措施建议。研究结果表明:该泥石流沟内可参与泥石流活动的松散堆积物动储量为20.79×10⁴m³,分为冲洪积、残坡积、人工堆积和崩滑塌等4种补给来源,其中人工堆积所占比重最大;经动力学分析,洪峰流量值在10年一遇的降雨条件下为17.03m³/s,20年一遇的降雨条件下为19.21m³/s,50年一遇的降雨条件下为22.10m³/s,100年一遇的降雨条件下为24.28m³/s,一次固体冲出总量分别为0.55×10⁴m³、0.63×10⁴m³、0.72×10⁴m³、0.79×10⁴m³,属于小型泥石流,最大危险区面积为0.2763km2。通过评价分析,该泥石流沟仍存在爆发小型泥石流的可能性,将对下游车道沟村以及行车和行人的生命财产安全造成威胁。研究成果可为延庆地区该类泥石流单沟预警模型研究和灾害防治提供科学依据。     

延庆地区水头村泥石流形成条件及发展趋势

水头村泥石流沟是延庆地区典型沟谷型泥石流沟之一,具易发性高、危险性大的特点,严重威胁下游水头村村民。本文以水头村泥石流沟为研究对象,通过精细调查与GIS统计分析,获取了该流域降雨、地形地貌、物质来源等信息,对泥石流流域分区特征和形成条件进行研究,综合14个识别因子,确定了该泥石流沟的发展阶段,并预测其发展趋势,通过单沟泥石流堆积区公式预测了该流域最大危险区,并提出了防治措施建议。研究表明：水头村泥石流沟内松散堆积物动储量达27.96万 m³,其中以残坡积和冲洪积为主要物源;该泥石流属于暴雨-沟谷型-支沟群发型泥石流沟,发展阶段处于形成期,最大危险区面积为0.737 km²,威胁沟口水头村住户21户59人和红水公路350 m。建议采用定期巡视+局部物源稳固+清理排导槽相结合的防治措施。研究成果可为该区泥石流灾害防治提供基础数据支撑和科学依据。     

鹿鸣乡松树林泥石流特征与防治

介绍了松树林泥石流流域特征,根据不同类型分别统计了坡面侵蚀物源、沟道堆积物源及不良地质灾害等松散物源,分析计算了泥石流容重、流速、流量、一次冲出量等特征参数,统计了泥石流的威胁对象,根据危险等级,提出了防治对策。     

尖山包沟泥石流成因及动力学特性研究

尖山包沟区域极端气温差为40.6℃、极端地温差为77.7℃,沟域所在地区多年平均降雨量为1058 mm,24h降雨强度可达111.5 mm。流域沟内地层岩性以软质—极软质岩为主,流域内松散固体物质总量约2.0×10~7m~3;沟内相对高差达1328 m,沟床平均坡降为132.21‰;尖山包沟泥石流的爆发因素主要是丰富的固体物源、丰沛的降雨和暴雨降雨强度、陡峭的地形等。在高强度暴雨的作用下,聚集的洪水裹挟着松散固体物质沿陡峭的山沟快速向下流动而形成泥石流;泥石流流速为4.77 m/s,整体冲压力为3.71 k Pa,泥石流最大冲起高度为1.16 m,受阻爬高可达1.85 m。     

喜德县波振沟泥石流形成条件及动力特征2

波振沟位于四川省凉山州喜德县境内孙水河左岸,属于川南红层地区典型沟谷型泥石流沟。通过工程地质调查与遥感影像解译,研究了该泥石流形成条件和机理,获取了泥石流动静力学参数。调查研究表明:(1)波振沟流域地貌正处于壮年期发育阶段;(2)泥石流容重1.64g/cm3,属于过渡(偏稀)性泥石流;(3)波振沟流域内还存在大量崩滑体及沟道松散堆积体,松散物源近4×105m3,在强降雨作用下容易启动泥石流,建议加强综合防治。该研究对砂泥岩互层地区泥石流形成机理的认识有一定帮助,对波振沟泥石流防治具有参考价值。     

基于DEM的泥石流堆积物产量计算方法的探讨

分析、讨论了泥石流堆积物产量的各种计算方法,并基于DEM法的计算原理,针对新疆乌恰县境内泥石流堆积物产量进行了实际计算,证明了DEM法在计算泥石流堆积物产量中的可行性。     

赵河泥石流成因分析

通过系统分析地形条件、区域构造、新构造运动及地震、堆积物、人类工程活动以及气候条件对泥石流的影响,揭示了赵河泥石流形成的主导因素和诱发因素,为泥石流灾害的防治提供了理论依据,同时也为同类地区泥石流的成因分析提供了参考借鉴。     

青海托拉海冲洪积扇区水文地质及水质分析

研究区位于沙松乌拉山前托拉海冲洪积扇区,区内沉积了厚度较大的第四系松散沉积物,其岩性主要为卵砾石、砂砾石及砂层。含水层厚度大于50 m,为赋存地下水提供了良好的空间场所。该区因降水稀少,蒸发量大,松散岩类孔隙水主要接受托拉海河水的下渗补给,主要河水补给来源于托拉海东沟、西沟,其中托拉海西沟年平均流量较小。洪积扇中前部地区地下水位埋深一般为20~65 m,水量较丰富,水质较好。     

凤城市石城镇车头峪村泥石流治理防治工程分析

通过对凤城市石城镇车头峪村的水文、地质勘查等资料的研究,采取了护砌或挡土墙措施加固流域各段不稳固河岸,同时清除河道内松散堆积物,控制物源;修建谷坊坝,消能并控制形成区泥沙输移;修建排导渠及导流堤,使得泥石流顺利排泄至主河道中,达到了消除泥石流地质灾害,保护人民生命财产安全的效果。     

宝兴县和平沟泥石流基本特征及成因机制分析

和平沟为一老泥石流沟,历史上多次爆发泥石流。该沟流域面积15.90 km2,主沟长7.4 km,主沟平均纵比降208‰,松散固体物源总量为87.36×104m3,近期可能参与近期泥石流活动量约7.9×104m3。在有利的自然地质环境条件和人为因素相互作用下形成泥石流灾害。     

甘肃临泽县地质灾害类型及特征

甘肃省张掖市临泽县是河西走廊地质灾害最为发育的县区之一。通过实地测量、调查评价和综合研究等手段,在概述县域自然地理条件及地质背景的基础上,县域内已有的地质灾害共30处,其中泥石流沟29条主要集中分布于祁连山和合黎山山前与走廊平原的过渡带,尤其是北部合黎山山前连片分布;崩塌1处为斜坡坡度65°的独山子崩塌。从地形条件、物质条件、降雨条件以及人类日益工程建设活动等方面研究表明,较大的沟床纵坡降比和流域面积、丰富的松散固体物质和短时间聚集的充足水源(多是有暴雨形成)是形成区内泥石流的基本条件。崩塌(不稳定斜坡)于公路沿线的人工开挖坡度大于60°的边坡地带。临泽县地质灾害具有不均匀性、突发性、周期性。该研究为县域地质灾害防灾减灾提供科学依据。     

The debris flows of Austria

The topographical, geological and hydrological conditions of the Eastern Alps determine the variability of possibilities for debris flow activities in Austria. For instance the loose masses like “Altschutt” by Stiny (1931)—these are in most cases moraines in high altitude—cause often debris flow disasters in the western federal states of Austria. The rainfall intesities reach world records along the southeastern ranges of the Alpes (600–670 mm in two and a half hour). Along the northern and southern border ranges occur also daily amounts of 200–250 mm. The volumes of deposits by disasters reach amounts of about hundred thousand or million cubicmeters. The geomorphological form of the debris cone or the alluvial fan allows to indicate the type of torrent and the degree of hazard impact. Using the geomorphological form along the course it is possible to calculate the velocity of the debris flow.     

太原西山地区泥石流发育特征

结合太原西山地区的自然地理与地质环境，从泥石流沟的判别、泥石流的形成条件及分布等方面，阐述了泥石流的发育特征，提出了泥石流的流体特征计算和堆积数值模型的预测方法。     

Une méthodologie d'analyse et de cartographie de l'aléa "initiation de laves torrentielles" – application au torrent du Bragousse (France)

Debris flows may result in personal injury or loss of life as well as damage to constructions. The economic consequences of such events are important, and likely to become more so with increasing urbanisation. In this paper, "debris flow" is defined as a viscous flow of saturated materials at high velocities of up to 20?m/s in channels. These materials have a high concentration of solids such that their dynamics may be considered at the interface between mechanical and hydraulic flow. The occurrence of a debris flow results from a number of interrelated factors including topography, geology, geomorphology and hydrogeology. The triggering factor is most often water, frequently a violent rainstorm. In order to identify the initiation mechanisms, it is necessary to have a knowledge of the environmental situation in the particular catchment area. Clearly, this will involve an understanding of: (1) the catchment area and its geological conditions; (2) the climatic characteristics of the locality and the nature of the materials in the source area; (3) the pattern of such events in the past. In order to obtain such an understanding, a dual approach of field and laboratory work was considered appropriate. Twelve catchment areas in the northern and southern French Alps were studied to assess the significance of the three aspects mentioned above. The study of numerous debris flow deposits sampled in these catchment areas suggested two types of debris flows: those with a cohesive matrix and those with a granular matrix. In the field, they were categorised on the basis of a morphological consideration of the area as well as according to the texture and grain size of the material in the flow. In the laboratory, granulometric tests were used. In addition, the granulometric and geotechnical characteristics of the source areas were compared with those of the debris flow materials. The grain size distribution appears to be an important factor in determining the likelihood that the source area materials would be moved by violent storms and from a debris flow. From tests undertaken on the <20?mm fraction, superficial deposits with between 16 and 40% of the particles of <50?μm seemed to be most likely to result in debris flows. This paper discusses the fieldwork undertaken from the upper catchment area down to the channel of a debris flow. Each mechanism is described with an analysis of the geological and topographical contexts, the extent of the movement and the hydrological processes that lead to the initiation of a debris flow. On the basis of this, maps have been produced to show the potential for the initiation of a debris flow. Five criteria were chosen to define the debris-flow hazard: (1) slope angle; (2) nature of the geological formation and hydrogeological characteristics; (3) slope erodability and instability; (4) grain size; (5) available volumes of superficial deposits present in the source area. These five indices form the global index. The maps show the spatial distribution of the hazard and can be useful in determining the most appropriate remedial/protective works to be undertaken in zones of the greatest risk.     

蔡达沟泥石流形成条件及特征研究

为研究蔡达沟泥石流形成条件和分区特征,通过收集工程区附近多年的气象资料及有关区域地质资料,从而对蔡达沟沟谷泥石流的形成条件和泥石流活动特征进行了分析。结果表明:该区高强度的暴雨使得泥石流的启动条件得以满足,同时密集的断裂构造及构造运动提供了足够的物源,适合分区的沟床比降,使得堆积条件和势能充分发挥;泥石流各区的堆积、颗粒成分、粒径呈现一定的规律性分布,且不同区域差别较大。     

Hydraulic mechanism and time-dependent characteristics of loose gully deposits failure induced by rainfall

Failure of loose gully deposits under the effect of rainfall contributes to the potential risk of debris flow.In the past decades,researches on hydraulic mechanism and time-dependent characteristics of loose deposits failure are frequently reported,however adequate measures for reducing debris flow are not available practically.In this context,a time-dependent model was established to determine the changes of water table of loose deposits using hydraulic and topographic theories.In addition,the variation in water table with elapsed time was analyzed.The formulas for calculating hydrodynamic and hydrostatic pressures on each strip and block unit of deposit were proposed,and the slope stability and failure risk of the loose deposits were assessed based on the time-dependent hydraulic characteristics of established model.Finally,the failure mechanism of deposits based on infinite slope theory was illustrated,with an example,to calculate sliding force,anti-sliding force and residual sliding force applied to each slice.The results indicate that failure of gully deposits under the effect of rainfall is the result of continuously increasing hydraulic pressure and water table.The time-dependent characteristics of loose deposit failure are determined by the factors of hydraulic properties,drainage area of interest,rainfall pattern,rainfall duration and intensity.