崩岗泥砂流流体和流动特性及其输沙研究——以广东德庆县径深崩岗为例  

Hydrodynamic Properties of Benggang-Related Mud-Sand Flow and Sediment Yield: A Case Study of Jingshen Mud-Sand Flow at Deqing County of Guangdong, China

作　　者：岳梦 刘希林[1] YUE Meng;LIU Xilin(School of Geography and Planning,Sun Yat-Sen University,Guangzhou 510006,China)

机构地区：[1]中山大学地理科学与规划学院,广州510006

出　　处：《山地学报》2022年第6期859-874,共16页Mountain Research

基　　金：国家自然科学基金(41971006)。

摘　　要：崩岗泥砂流是崩岗流域的主要侵蚀和搬运营力,由其输送至崩岗流域外的泥沙对华南地区的生产、生活及生态造成严重影响。然而,泥砂流的发生具有突发性,对其进行现场观测和采样较困难,对泥砂流的物理性质、运动过程以及输沙情况尚不清晰。本研究通过对广东德庆县径深崩岗泥砂流进行野外观测与采样分析,得出其流体特性、流动特性和输沙特征。结果表明:(1)泥砂流平均容重为1.10 t/m^(3),平均中值粒径为0.113 mm,粒度分布曲线多为双峰型;(2)泥砂流平均含沙量为155.15 kg/m^(3),属于高含沙水流;泥砂流平均输沙率为5.15 kg/s,累计最大输沙量达26 998 kg;(3)泥砂流以急紊流为主,水动力学参数弗汝德数、雷诺数、水流剪切力、水流功率和单位水流功率与泥砂流输沙量和输沙率呈正相关关系,糙率系数与泥砂流输沙量和输沙率呈负相关关系,阻力系数与泥砂流输沙率呈负相关关系;(4)泥砂流输沙量和输沙率随着降雨量和降雨强度的增大而增大。本文可以为解决华南崩岗侵蚀导致的生态环境问题提供科学依据。Benggang(collapsing granite hills) is a typical soil erosion phenomenon widely occurring in the granitic weathering zones of South China, characterized by its capacity of extreme landform renovation. Mud-sand flows feed by Benggang sediments are main erosion and transportation force in creating Benggang landscape or Benggang valley in the areas. Production, living and eco-environment in a community in the proximity of a Benggang valley often seriously suffer from striking or occupying of sediments transported by mud-sand flow out of the valley. A proper understanding of the behavior of Benggang-related mud-sand flow is helpful to better solve the ecological and environmental problems caused by Benggang erosion. Unfortunately, by now it has not yet been knowledgeable for Benggang. For example, an occurrence of mud-sand flow took place with minutes, quite difficult to observe and sample it on site;the physical properties of mud-sand flow, movement process and sediment migration are still not very clear. In this study, a typical Benggang-related mud-sand flow happened at Jingshen village, Deqing County, Guangdong Province, China was investigated as case study for interpretation of its hydrodynamic mechanism. Field observation and sample tests were conducted to measure the rheological properties, flow characteristics and sediment-yield characteristics of mud-sand flows. The following results are obtained:(1) The average volume weight of the Jingshen mud-sand flows was 1.10 t/m~3, mostly exhibiting a bimodal particle size distribution curve, with an average median particle size 0.113 mm.(2) The mud-sand flows were assorted as hyper-concentrated flow with an average silt concentration of 155.15 kg/m~3. Its average sediment yield rate was 5.15 kg/s, with the cumulative sediment yield up to 26 998 kg.(3) The mud-sand flows were categorized as turbulent current. The hydrodynamic parameters including Froude number, Reynolds number, flow shear stress, stream power and unit stream power were positively correlated with the se

关 键 词：崩岗泥砂流 野外观测 水动力学参数 高含沙水流 输沙特征 广东 

分 类 号：P934[天文地球—自然地理学] S157.1[农业科学—土壤学]