晋西北典型黄土陡坡急流冲刷调查研究

随着气候的变化，近年来晋陕北部暴雨集中，来势快急，对当地黄土高原造成巨大影响，陡坡急流造成坡面大量崩塌、滑坡，形成了侵蚀堆积体和沟道泥石流，对乡村和中小城镇造成安全威胁。为了研究晋西北典型黄土高原陡坡急流冲刷情况，通过资料搜集、野外勘察和测量，选取黄土裸坡冲刷状况进行取样和现场实测，获得当地降雨资料，并得到 3 种典型裸坡的侵蚀特征、形态参数和颗粒级配。通过建立边坡泥沙颗粒受力模型，分析裸露黄土边坡坡面急流冲刷的发生条件。研究发现: 降雨特征、土层特性与边坡形态共同影响着边坡冲刷侵蚀的发展。边坡冲沟沟深沿程呈波动趋势，直线型边坡冲沟沟深随径流量的增加而增大; 凹型边坡冲沟沟深随径流量的增加而增大，随坡度的增大而减小; 凸型边坡冲沟沟宽沿程沟深随径流量的增加而减小，随坡度的减小而减小。边坡冲沟沟宽沿程呈抛物线变化趋势，沟宽沿 BC 坡段减小，沿 DE、FG 坡段增大。

Investigation of typical torrential erosion on steep loess slope in Northwest Shanxi

Along with the climate change，rain storms are concentrated in the regions of North Shanxi and North Shaaxi with strong and rapid oncoming force and great impact on the local loess plateau，from which a large amount of collapses and landslides of slope surface are caused by steep-slope torrent，thus erosive deposit and gully debris flow are formed with safety threat upon the countryside and the mid-small cities therein. In order to study the typical steep-slope torrent within the region of Northweat Shanxi，the scouring state of bare loess slope is selected to carry out the relevant sampling and in situ measurement through data collection and field investigation and measurement，and then the local rainfall data is obtained，while the erosion characteristics， pattern parameters and particle gradation of three kinds of bare slope are obtained as well. By means of establishing the stress model of slope sediment particle，the occurrence condition of the torrential erosion on the bare loess slope surface is analyzed. The study result shows that the development of the slope torrential erosion is impacted by the joint effects of the rainfall characteristics，the features of soil layer and the slope patter jointly. The on-way depths of the slope gullies exhibit fluctuated trends，that is to say，the depth of the slope gully of the straight-line typed slope increases along with the increase of runoff; the depth of the slope gully of the concave slope increases along with the increase of runoff and decreases along with the increase of the slope gradient; while the width of the slope gully of the convex slope decreases along with the increase of runoff and decreases along with the decrease of the slope gradient. The on-way widths of the slope gullies present parabolic trends of change with the decrease along the BC slope section and the increase along the increases of DE and FG slope sections.