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泥石流对山区河流河床演变的影响

文献类型:学位论文

作者何易平
学位类别博士
答辩日期2003
授予单位中国科学院成都山地灾害与环境研究所
授予地点成都
导师崔鹏
关键词泥石流 主河 河床演变 实验 山区
其他题名Influence of Debris Flow on River Channel Change of Mountains He
学位专业自然地理学
中文摘要山区河流的河床演变是河床演变研究的重点和难点,泥石流广泛分布于占我国国土面积67%的山区,因此研究泥石流对山区河流河床演变的影响具有重要的意义。本文以小江流域为例,系统分析了泥石流沟道的冲淤与演变特性、堆积扇的发育与演化特点、泥石流培河判别式、汇流区泥沙淤积和河床演变特点、泥石流多发区主河河床演变规律等。取得了如下成果:1通过野外考察、长达4年的冲淤监测测量和四期大比例尺(1:1000)地形测量,以及135场室内模拟实验,获得了大量原始资料和实验数据,主要包括:1999-2002年蒋家沟泥石流冲淤监测断面实测数据(累计实测335个断面);1957-2002年蒋家沟沟道演变数据;1999~2002年蒋家沟泥石流汇流区四期1:1000实测地形图及冲淤监测断面实测数据(累计实测54个断面);70场泥石流培河实验数据和65场泥石流交汇实验数据。2根据蒋家沟泥石流冲淤监测成果,推导出侵蚀基准改变引起沟道冲淤的计算公式,总结了不同位置沟道的冲淤特点;分析了蒋家沟1957~2002年沟道冲淤情况,发现山区泥石流支沟的沟床演变具有显著的冲淤不平衡特性。3根据泥石流堆积扇的室内模拟实验和野外大比例尺实测成果,提出了泥石流堆积扇的演化特征,探索了泥石流堆积扇的发育和泥石流入汇角、泥石流与主河流量比(或动量比)的定性关系,建立了泥石流堆积扇的扇面高程模型(1)。EA=ΣKiRnθmn=0,1,2,3,4(1)4通过70场泥石流堵河实验,揭示了泥石流入汇角(6)、容重(γ)、主河与泥石流单宽流量比(FR)和动量比(MR)对堵河的作用规律,提出了泥石流治河的动量和流量判别式(2,3),在此基础上推导出基于泥石流容重、主河与泥石流单宽流量比(FR)的泥石流不堵河的最大角度计算公式(4)。CM=InMR-1.189(1-cosθ)2-3.677γ<-12.132(2)CF=InFR-0.883(1-cosθ)2-2.587γ<-8.572(3)θ<arccos(1-√(InFR+8.572-2.587γ)/T.883)(4)5通过65场泥石流入汇实验,定量分析了泥石流所携带的泥沙在主河淤积的长宽比(L)、最大淤积厚度(Hmax)、平均淤积厚度(Haver)和淤积率(S)与泥石流入汇角(6)、主河与泥石流单宽流量比(FR)(或动量比;MR)的关系(5~9)。根据蒋家沟1999~2002年汇流区的断面和地形测量结果,总结了汇流区不同部位的河床演变特点。L=l/W=4.2328MR+5.2241,R。0.796(5)Hmax=0.0159(1-cosθ)2-0.0813MR+0.123(6)Have=0.0101(l-C。S旷一0.0293MR+0.04318(7)S=0144(1-cosθ)2-0.300MR+6.35(8)S=0.134(1-cosθ)2-0.181MR+0.709(9)6通过分析4\江干流1957A1000年河床演变情况,探索了泥石流对山区河流河床演变(河型、河床平面形态。纵剖面形态)的影响,初步揭示了泥石流多发区河床演变的宏观规律。
英文摘要River channel change in mountains is an important component of fluvial process, hi China, debris flows extensively distribute in mountains, 67.2% of the territorial area, and have immense influence on channel change of main flow. However, because of its complex nature and multi-factor cause, few quantitative researches have been given to stream change of debris flow anabranch, the relation of debris flow sediment transportation and channel change of main flow in mountains. This study systemically analyzes the silting and cutting characteristics of debris flow stream, developmental characteristics of deposition fan, sediment deposition and bed form change in the junction, and fluvial process in the area with frequent occurrence of debris flows, based on previous researches results, field investigation, topographic survey, remote-sensing images interpreting, and simulation experiments. Xiaojiang Basin, one of the famous areas of rainfall debris flow occurrence, located at the southwestern China, was selected to for a case study in this thesis. The originality study and innovations of this thesis are as follows: According to field investigation, four years' continuous topographic surveying, remote sensing images interpreting, and 135 groups' debris-flow simulation experiments, a large number of original data were obtained, such as topographic measuring data of Jiangjia Gully (about 15,000 measured points from 335 profiles in continuous 4 years from 1999 to 2002), stream channel change data of Jiangjia Gully from 1957 to 2002, 4 periods' 1:1000 digital elevation model and topographic measuring data at the confluence area of Jiangjia Gully and Xiaojiang River (about 3000 measured points from 54 profiles from 1999 to 2002), 70 groups' experimental data on main flow blockage, 65 groups' experimental data on debris flow junction, etc. As a case study in Jiangjia Gully, the influence of erosion basis on gully silting and erosion were systemically analyzed, and a model of calculating the value of erosion and silting was presented based on the surveyed data from 1999 to 2002 and previous research data. Furthermore, some characters of gully cutting and silting at special sections were introduced in detail, such as the sections at gully mouth, in the upper, middle, and lower reaches of monitor zone, the compound cross section by debris flow overflow, and the curved sections. After analyzing the history topographical map of Jiangjia Ravine Catchment, we find that stream change of debris-flow anabranch has the characteristic of obvious unbalance of cutting and silting. 3 Based on four periods' topographic surveying and 34 groups' simulation experiment of debris flow depositions, the developmental characteristic and surface model (Eq.l) were summarized, and the effects of water discharge (or momentum), debris flow discharge (or momentum), and junction angle on the thickness, area, and length-width ratio of deposition fan, were introduced in detail.
学科主题灾害学
语种中文
公开日期2011-08-08
源URL[http://192.168.143.20:8080/handle/131551/3310]  
专题成都山地灾害与环境研究所_成都山地所知识仓储(2009年以前)
推荐引用方式
GB/T 7714
何易平. 泥石流对山区河流河床演变的影响[D]. 成都. 中国科学院成都山地灾害与环境研究所. 2003.

入库方式: OAI收割

来源:成都山地灾害与环境研究所

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