怒江东月各大型高速远程泥石流运移及致灾机理

发布时间：2018-03-03 08:27

  本文选题：泥石流　切入点：运移　出处：《昆明理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：东月各沟位于怒江河谷左岸,怒江流域属于低纬度高山峡谷地貌,区域内新构造运动强烈,相对高差大,呈立体气候特征。东月各沟呈狭长“v”字型特征,两岸植被发育覆盖率高,河床基岩出露,砾石堆积,存在常年性水流。2010年8月18日东月各沟发生大型高速远程粘性泥石流,浆体运移距离近10 km,泥石流堆积区房屋破坏,工厂摧毁,公路交通基础设施荡然无存,给社会经济和人民财产带来严重的损失。山区是泥石流多发地区,但东月各沟泥石流远程运移又造成如此巨大的灾难并不多见,深入研究东月各泥石流运移机理及致灾特性对科学研究和泥石流灾害防治具有重要意义。通过对东月各沟泥石流现场勘察,分析本次泥石流运移及致灾特征,以室内、外模型实验为手段,研究得出主要结论如下:1.东月各沟湿润、浅水区域的基岩、卵石表面生长的生物膜可以明显降低其表面摩擦阻力系数,减少水流、泥石流浆体在其表面的能量损耗,增大其运移速度。东月各沟泥石流浆体能够在沟床比降131‰的沟谷中运移近10 km,与沟谷中生长的生物膜存在一定的联系。2.泥石流浆体易在沟谷两岸干燥区域堆积,不易在沟谷湿润、浅水环境残留,主要原因是在湿润、浅水环境生长的生物膜降低基岩、卵石表面的摩擦阻力,泥石流浆体在此环境下更易运移。3.东月各泥石流沟流通区域中下部开阔平缓,沟床坡度较小,特别是在距离堆积区域500 m范围内,平均坡度约为5°,流经此区域的泥石流应降速减能,而东月各泥石流仍造成巨大灾害。现场调研及模型实验分析得出堆积区上游500 m处的泥石流龙头停滞坝溃坝二次形成泥石流,瞬间巨量浆体高速喷向堆积区,是本次泥石流致灾严重的关键因素。4.通过五组不同高度的泥石流龙头坝溃坝模型实验,结合东月各沟谷形态、泥石流浆体混杂较多巨石及大型乔木等现象,得出东月各泥石流浆体在沟谷运移过程中应存在多次堵塞坝在短时间内溃坝二次形成泥石流现象。东月各泥石流运移过程中大小阵流共发生13次,与东月各泥石流堵塞坝溃坝现象有关。
[Abstract]:Each trench of the East Moon is located on the left bank of the Nujiang River Valley, and the Nujiang Valley belongs to the low-latitude alpine canyon geomorphology. The neotectonic movement in the area is strong, the relative height difference is large, and it is a three-dimensional climatic feature. Each trench in the East Moon is characterized by a long and narrow "v" shape. The vegetation coverage on both sides is high, the bedrock is exposed, gravel accumulates, and there is perennial water flow. In August 18th 2010, large high speed and long distance viscous debris flow occurred in each gully of Dongyue, and the distance of slurry transport was close to 10 km, and the houses in the debris flow accumulation area were destroyed. The destruction of factories and the destruction of road transport infrastructure have caused serious losses to social economy and people's property. Mountainous areas are prone to mudslides, but remote migration of mudslides in the eastern moon is rare. It is of great significance for scientific research and prevention of debris flow disaster to study the mechanism and characteristics of debris flow movement in Dongyue. The main conclusions of the study are as follows: 1. The biofilm growing on the surface of pebbles can obviously reduce the friction coefficient and reduce the flow of water in the wetted and shallow water regions of the east moon, and the biofilm growing on the pebble surface can obviously reduce the friction coefficient on the surface of the pebble. Energy loss of debris flow slurry on its surface, The debris flow slurry can be transported nearly 10 km in the gully with a ratio of 131 鈥，

本文编号：1560269