澜沧江中路沟泥石流危险性评价研究

发布时间：2018-04-17 00:12

本文选题：中路沟泥石流 + 组合赋权　；参考：《成都理工大学》2017年硕士论文

【摘要】：在对山区进行开发建设时,常会碰到一种特殊的地质灾害——泥石流。运动时携带许多泥沙和石块,当它发生的时候,对其危险范围内的物体构成极大的破坏力,因为其运动的时候能量巨大,速度飞快。我国西南山区山高地陡,水电工程常在这种高山峡谷的地方修建,由于受地形的限制,坝址附近能够利用的场地非常少,然而水电站建设过程中却需要很多空置的场地用来布置各类建筑设施和安置水电人员。因此,常利用近坝区附近的泥石流沟口布置场地和安置水电人员。本文以澜沧江托巴水电站中路沟泥石流为研究对象,通过野外现场调查结合遥感影像图,对其形成条件和流域特征进行了分析,对其物源进行了详细调查,辅助Arcgis、Autocad等软件,采用了组合赋权的模糊综合评判法对中路沟泥石流进行危险性评价,并结合刘希林评价模型进行评价分析。采用FLO-2D对中路沟泥石流进行模拟分析,模拟4种不同频率下泥石流运动的情形,从而可得中路沟泥石流的泥深、速度、面积以及方量。然后建立中路沟泥石流危险性等级划分标准,得到中路沟泥石流危险分区图,最后对中路沟提出防治建议。本论文从下面四个方面进行研究:(1)对中路沟进行了非常详细的野外调查来分析中路泥石流沟发育背景。(2)对中路沟泥石流的形成条件进行了分析,研究区地形总体上属侵蚀中高山地貌,沟谷两侧斜坡地形坡度较陡,植被覆盖率中等,物源方面根据野外详细调查和遥感影像图,统计了沟内物源类型和数量,然后对中路沟的流域特征开展仔细的描述,通过现场颗粒分析实验,得到堆积扇的粒度组成情况,绘制颗粒百分含量曲线图和百分含量直方图,从而求得土粒分布特征参数和粒径分布情况。根据现场走访,对中路沟泥石流的活动历史进行了访问,并对其发展趋势做了分析。(3)依据现场实地调查情况并结合1:50000地形图,来对中路沟泥石流一些参数如主沟长度、平均纵坡降、高程等进行获得。采用组合赋权的模糊综合评判法对中路沟泥石流进行危险性评价,主要从泥石流灾害历史、地形地貌、气象水文、人类活动等方面选取评价因子,共选取了10个评价因子,经计算得出的结果为中度危险,并结合刘希林评价模型进行分析评价。(4)为了能够更加直观的反映中路沟泥石流的危险性,采用FLO-2D数值软件模拟不同降雨频率下(P=0.5%,P=1%,P=2%,P=5%)的冲出规模,运动速度,堆积深度。然后对已暴发的20年一遇数值模拟结果分别从准确度和精确度分析,表明模拟效果很好。建立中路沟泥石流危险性等级划分标准,得出4种重现周期的泥石流危险分区图。针对中路沟泥石流以上研究成果,对中路沟泥石流提出防治建议。
[Abstract]:In the development and construction of mountainous areas, a special geological hazard-debris flow is often encountered.When moving with a lot of sand and rocks, when it occurs, it constitutes a great deal of damage to the object in its dangerous range, because it moves with great energy and fast speed.The mountains are steep in the southwest of China, and hydropower projects are often built in such high mountain canyons. Due to the limitation of the topography, there are very few sites near the dam site that can be used.However, in the process of hydropower station construction, many vacant sites are needed to arrange all kinds of construction facilities and hydropower personnel.Therefore, the debris flow near the dam area is often used to arrange the site and the hydropower personnel.In this paper, the debris flow along the middle road of Toba Hydropower Station in Lancang River is taken as the research object. Through field investigation and remote sensing image map, the formation conditions and basin characteristics are analyzed, and the source of the debris flow is investigated in detail to assist the software such as Arcgis-Autocad, etc.The fuzzy comprehensive evaluation method of combined weight is used to evaluate the risk of debris flow in the middle channel, and the evaluation model of Liu Xilin is used to evaluate and analyze the risk.The mud depth, velocity, area and volume of debris flow in the middle channel debris flow can be obtained by using FLO-2D to simulate the debris flow movement under four different frequencies.Then the risk classification standard of middle channel debris flow is established, and the risk zoning map of middle road gully debris flow is obtained. Finally, the prevention and cure suggestions are put forward to the middle road gully.This paper has carried on the research from the following four aspects: 1) has carried on the very detailed field investigation to the middle road ditch to analyze the middle road debris flow gully development background. 2) has carried on the analysis to the middle road channel debris flow formation condition.The topography of the study area generally belongs to the erosive middle alpine landform, the slope slope on both sides of the gully is steep, the vegetation coverage is medium. According to the detailed investigation in the field and the remote sensing image map, the type and quantity of the material source in the gully are counted.Then the watershed characteristics of Zhongluogou are carefully described. Through the field particle analysis experiments, the particle size composition of the accumulative fan is obtained, and the particle percent content curve and the percentage content histogram are drawn.The characteristic parameters and particle size distribution of soil particles are obtained.According to the site visit, the activity history of the debris flow in the middle channel is visited, and its development trend is analyzed. (3) based on the field investigation and combining with the 1: 50000 topographic map, some parameters such as the length of the main ditch of the debris flow in the middle road are analyzed.Average vertical gradient, elevation, etc.The risk assessment of debris flow in middle channel is carried out by using the fuzzy comprehensive evaluation method with combined weight. The evaluation factors are selected from the aspects of debris flow disaster history, landform, meteorology and hydrology, human activities and so on. A total of 10 evaluation factors are selected.In order to reflect more intuitively the risk of debris flow in the middle channel, the FLO-2D numerical software was used to simulate the scale of rushing out by using FLO-2D numerical software to simulate the different rainfall frequency.Speed of movement, depth of accumulation.Then, the accuracy and accuracy of the numerical simulation results are analyzed, which show that the simulation effect is very good.The classification standard of debris flow hazard grade in middle road gully was established, and four hazard zoning maps of debris flow with recurrence period were obtained.In view of the above research results of middle channel debris flow, the prevention and cure suggestions are put forward for middle road gully debris flow.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P642.23

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