设计水槽实验分析不同流态下的河流扇沉积体  

Design and Analysis of Flume Experiments on Fluvial Fan Sedimentation under Different Flow Velocity

作　　者：张森 孙世坦 袁晓冬 张元福[1,2] 霍艳翠 葛鹏程 ZHANG Sen;SUN Shi-tan;YUAN Xiao-dong;ZHANG Yuan-fu;HUO Yan-cui;GE Peng-cheng(School of Energy Resources,China University of Geosciences,Beijing 100083,China;PetroChina Research Institute of Petroleum Exploration&Development,Beijing 100083,China)

机构地区：[1]中国地质大学(北京)能源学院,北京100083 [2]中国石油勘探开发研究院,北京100083

出　　处：《科学技术与工程》2023年第17期7212-7220,共9页Science Technology and Engineering

基　　金：国家科技重大专项(2017ZX05009-002)。

摘　　要：河流扇作为近年来的沉积学热点问题,引起了诸多学者的广泛关注。为研究自然界中不同气候条件下河流扇的发育特征,通过控制变量法针对河流扇设计水槽实验。基于自然界中的气候条件模拟了固定流速和变流速两种流速状态下河流扇的发育。针对不同流态下发育的河流扇沉积体,分析河流扇的发育特征并建立相应的河流扇沉积模式。结果表明:典型河流扇在发育早期通过漫流迅速形成无朵叶体、扇体形态完整的河流扇;在发育中期,河口坝周期性地出现和消失,河流扇的中部和两侧交替发育,生长速度放缓;在发育末期,受限于可容纳空间的大小河流扇基本不发育,河道趋于稳定并沿末端发育朵叶体。河流扇的发育主要受早期的漫流沉积、中后期的河道摆动沉积和朵叶体沉积的影响,不同流速条件下河流扇的河道摆动沉积和朵叶体沉积存在较大差异。可见,河流扇的发育是水流流速、河道形态与沉积体3个因素相互作用影响的结果。The fluvial fan has received a lot of attention from academics recently,which is a contentious topic in sedimentology.In order to study the sedimentary characteristics of fluvial fans under different climatic,flume experiments were designed by using the control variable method.According to the natural climatic conditions,flume experiments were used to simulate the fluvial fan under fixed and variable velocity conditions.According to the experimental results,the sedimentary characteristics of the fluvial fan were analyzed and the corresponding model was established.The results show that there are three different development stages of typical fluvial fan.In the early stage,overflow quickly forms a fluvial fan with no lobe and complete fan shape.In the middle stage,river mouth bars appear and disappear periodically,resulting in the alternate development of the middle and both sides of the fan,and the growth rate slows down.In the late stage,due to the size of the accommodation space,the fluvial fan stops developing,the river channel tends to be stable and develops lobules along the end.The development of fluvial fan is mainly affected by the early overflowing sedimentation,middle and late channel swing and lobular sedimentation.The channel swing sedimentation and lobular sedimentation of fluvial fan are quite different under different flow velocities.It is concluded that the development of fluvial fan is the result of the interaction of three factors:flow velocity,channel shape and sedimentary body.

关 键 词：河流扇 水槽实验 沉积体系 河流扇控制因素 

分 类 号：P512.2[天文地球—地质学]