云南东川蒋家沟泥石流2003—2014年冲淤演变特征  

Characteristics of Debris Flow Erosion and Deposition at Jiangjia Gully,Dongchuan,Yunnan Province,China for 2003-2014

作　　者：方迎潮 王道杰[1] 何松膛 兰慧娟 常士秋 FANG Yingchao;WANG Daojie;HE Songtang;LAN Huijuan;CHANG Shiqiu(Key Laboratory of Mountain Hazards and Earth Surface Process,Chinese Academy of Sciences,Institute of Mountain Hazards and Environment,Chinese Academy of Sciences&Ministry of Water Conservancy,Chengdu 610041,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院水利部山地灾害与环境研究所山地灾害与地表过程重点实验室,成都610041 [2]中国科学院大学,北京100049

出　　处：《山地学报》2018年第6期907-916,共10页Mountain Research

基　　金：国家自然科学基金项目(41790434;41471010);国家科技支撑计划课题(2014BAL05B01)~~

摘　　要：冲刷和淤积是泥石流对沟床地貌塑造作用的两种方式,具有明显的时空差异性和不确定性,因此冲淤特征一直是泥石流研究的焦点。本文基于2003—2014年云南东川蒋家沟泥石流沟道典型断面的观测数据,分析了各典型断面泥石流冲淤特征,探讨了不同时段泥石流冲淤的时空分布特性,揭示了其主要影响因素的作用效应。研究表明:蒋家沟泥石流在2003—2014年间整体处于淤积的态势,其时空分布特性表现为随时间的推移,淤积区域逐渐由中下游向上游移动,从而表明蒋家沟泥石流在此期间的活动逐渐减弱,开始进入间歇期;同时分析发现,不同断面的冲淤演变特征既有相似性又有差异性,中上游的D1～D15、M3和M61等断面明显属于淤大于冲,而中下游的P4、PL2和PL1等断面则为冲大于淤,在中下游P5和P4断面间存在一个相对稳定的冲淤平衡点,最上游的D1断面平均淤积量达到15. 06 m,而最下游的PL1断面累计冲刷深约2. 74 m;在影响因素作用效应分析中,降雨量、单次泥石流规模、沟床比降以及输沙沟槽的弯曲系数均对冲淤具有明显的作用效应,其中输沙沟槽弯曲系数对冲淤的影响最为明显,其与平均冲淤的相关性系数为0. 8031。Scouring and silting are two ways for debris flow to shape the topography of a gully bed,with features of obvious space-time differences and uncertainties.Therefore,the investigation on the erosion and deposition characteristics has always been the focus of debris flow research.Based on the observation data collected at typical sections of debris flow channels along the Jiangjiagou Gully,Dongchuan,Yunnan Province,China from 2003 to 2014,this paper analyzed the characteristics of debris flow erosion and deposition in various typical sections,and then discussed their characteristics of the temporal-spatial distribution in different periods to reveal the effect of influencing factors.The study showed that the Jiangjiagou debris flows were in a state of siltation from 2003 to 2014 as a whole,and the siltation area gradually moved from the middle and lower reaches to the upper reaches with time,thus indicating that the Jiangjiagou debris flow activities gradually weakened during those periods and began to enter an intermission period.It also found that there were similarity and dissimilarity in the erosion and deposition evolution characteristics at different sections.At M3,M61,D1 and D15 sections of the middle and upper reaches there occurred obviously silting more than scouring,whereas at P4,PL2 and PL1 sections of the middle and lower reaches it had a larger scouring than silting.There was a relatively stable scouring and silting equilibrium point between P5 and P4 sections,with an average silting amount of 15.06 m at D1 section in the uppermost reaches,and a cumulative scouring depth about 2.74 m at PL1 section in the lowermost reaches.In the analysis of the effect of influencing factors,rainfall,the scale of a single debris flow,the slope of gully bed,and the bending coefficient of an sediment transport channel all had obvious effect on the sedimentation,among which the bending coefficient of a sediment transport channel had the most obvious effect for topography reformation and its correlation coefficient with t

关 键 词：蒋家沟 泥石流 冲刷 淤积 影响因素 

分 类 号：P642.23[天文地球—工程地质学]