内蒙克旗泥石流堆积区平面形态和危险范围预测模型

发布时间：2018-06-10 12:36

  本文选题：泥石流 + 危险范围　； 参考：《吉林大学》2015年硕士论文

【摘要】：泥石流是最为常见的山区地质灾害之一，每年在全世界范围内都会有大量泥石流现象出现。我国国土面积广阔，其中山地约占陆地总面积的三分之二，山区地势陡峭，而相对平坦开阔的地形使得泥石流堆积区成为当地居民生活生产的核心场所，同时作为泥石流最后的杀伤作用带，泥石流堆积区成为人类社会关注和科学研究的焦点。无论对于山区水利水电工程选址、道路选线、城镇选址布局以及制定综合防治规划，泥石流危险范围预测都具有重要的研究意义。 本文依据现场调查和室内试验资料，在分析内蒙芝瑞抽水蓄能电站下库区泥石流的地质环境、沟谷特征、发育特征及运动特征的基础上，结合前人学术成果，重点研究泥石流堆积区平面形态特征并提出形态参数K1和K2，利用非线性回归分析建立堆积区面积S和形态参数K1、K2与泥石流特征因子的函数关系式，构建泥石流危险范围预测模型，并与传统模型对比分析，同时采用预测模型对研究区内受损严重的泥石流堆积区进行预测评价。主要得到以下结论： 研究区地处我国北方，主要为温带季风气候，年降雨量多为400~800mm。区内泥石流多为低频或超低频泥石流，流域内松散物源较少，以稀性泥石流为主。泥石流发育阶段处于老年期或终止期，易发等级主要为轻度易发，单沟活动强度主要为弱。 泥石流堆积区平面形态主要为扇形和近似椭圆形，其中南方地区泥石流主要为扇形堆积，研究区泥石流则主要为近似椭圆形堆积。与以往定性描述研究不同，本文提出形态参数K1和K2定量评价堆积区平面形态，形态参数K1表征堆积区纵向延伸与横向延伸之比，，形态参数K2表征堆积区基本形状，扇形堆积区0.5K20.67，近似椭圆形堆积区0.67K2≤0.84。 采用泥石流一次冲出固体物质总量、泥石流容重和堆积区坡度建立堆积区面积S的方程式，采用泥石流流速、容重和堆积区坡度建立形态参数K1的方程式，且研究区近似椭圆堆积区形态参数K2取值0.67~0.84，组合后构建研究区泥石流危险范围预测模型，模型对最大堆积长度、宽度的预测误差较小。 通过将本模型与四种传统模型对比分析可知，传统模型主要针对泥石流堆积区一维特征建立预测模型，忽略了二维形态的变化或假定其为一定值，因此预测结果与实际有较大偏差，而本文针对堆积区二维特征直接建立预测模型，考虑其平面形态的变化，得到包含堆积区大小和形态的完整范围。
[Abstract]:Debris flow is one of the most common geological disasters in mountainous areas. China has a vast land area, in which the mountainous area accounts for about 2/3 of the total land area. The mountainous area is steep, and the relatively flat and open terrain makes the debris flow accumulation area the core place for local residents to live and produce. At the same time, as the last killing zone of debris flow, debris flow accumulation area has become the focus of human society and scientific research. It is of great significance for the site selection of water conservancy and hydropower projects in mountainous areas, the route selection of roads, the location layout of cities and towns, and the formulation of comprehensive prevention and control planning, and the prediction of debris flow hazard range. This paper bases on field investigation and indoor test data. On the basis of analyzing the geological environment, valley characteristics, developmental characteristics and movement characteristics of debris flow in the reservoir area of Inner Mongolia Zhirui pumped Storage Power Station, combined with previous academic achievements, The plane morphological characteristics of debris flow accumulation area are studied, and the morphological parameters K _ 1 and K _ 2 are put forward. By using nonlinear regression analysis, the functional expressions of the area S, K _ 1K _ 2 and the characteristic factors of debris flow are established. The prediction model of debris flow risk range is constructed and compared with the traditional model. At the same time, the prediction model is used to predict and evaluate the debris flow accumulation area which is seriously damaged in the study area. The main conclusions are as follows: the study area is located in the north of China, mainly in the temperate monsoon climate, the annual rainfall is 400-800mm. The debris flow in this area is mostly low frequency or ultra low frequency debris flow, and the loose material source is less in the basin, and the main debris flow is dilute debris flow. The debris flow development stage is in the old or terminating period, the susceptibility grade is mainly mild, the intensity of single channel activity is mainly weak. The plane shape of debris flow accumulation area is mainly sector shape and approximate ellipse shape. The debris flow in the southern region is mainly fan-shaped and the debris flow in the study area is approximately elliptical. Different from the previous qualitative description studies, the morphological parameters K1 and K2 are proposed to quantitatively evaluate the plane shape of the stacking area. The morphological parameter K1 characterizes the ratio of longitudinal to lateral extension of the stacking area, and the morphological parameter K2 characterizes the basic shape of the stacking area. The accumulation area is 0.5K20.67 in the sector accumulation area and 0.67K2 鈮

本文编号：2003249