摘要
为了分析泥石流对沟道冲淤的累积影响效应,根据蒋家沟1999—2014年泥石流沟道断面测量数据对沟道年际冲淤变化特征及影响因素进行了分析。结果表明:蒋家沟泥石流沟道断面形态变化主要表现为断面展宽、断面淤积抬高或冲刷降低;沟道宽度变化主要发生于1999—2009年,2009年后沟道宽度相对稳定,沟道冲淤速率逐渐减缓;沟道整体纵剖面曲线呈现下凹型,下凹度不断减小,2009年后下凹度在1.1左右波动,纵剖面整体比降不断增大,2009年后比降增加速率减缓;泥石流输沙规模减小、泥深及流速减小、支沟泥石流汇入、沟道下游排导工程是影响蒋家沟泥石流沟道冲淤的主要因素。研究成果可为泥石流流通及堆积区的防治提供参考。
In the aim of investigating the cumulative effect of debris flow on channel morphology, we analyzed the variations and influential factors of erosion and deposition in Jiangjia Gully according to sectional measurements from 1999 to 2014. Results revealed that the channel width increased continuously and the sectional height elevated or decreased depending on the erosion or deposition of channel. The channel width increased mainly from 1999 to 2009, and then remained stable after 2009 when erosion or deposition intensity decreased. Moreover, the curve of longitudinal profile of channel was concave, and the concavity index decreased gradually, fluctuating around 1.1 af- ter 2009. The gradient of channel profile increased gradually, but the increment alleviated after 2009. Decreases in the sediment discharge, depth and velocity of debris flow, and debris flow afflux from tributary, as well as debris flow drainage project in the downstream were dominant factors influencing the channel morphology.
出处
《长江科学院院报》
CSCD
北大核心
2017年第9期57-62,共6页
Journal of Changjiang River Scientific Research Institute
基金
国家自然科学基金面上项目(41371039)
国家重点基础研究发展计划项目(2015CB452704)
中国科学院山地灾害与地表过程重点实验室自主支持项目(Y3L1340340)
关键词
蒋家沟泥石流
沟道年际冲淤
下凹度
比降
冲淤速率
debris flow in Jiangjia Gully
inter-annuM erosion and deposition
concavity index
channel gradient
erosion and deposition rate
