土石山区山坡壤中流汇流界面研究——以太行山崇陵流域为研究区

Study on confluence interface of subsurface flow of hillslope in rocky mountainous area——a study case of Chongling Watershed in Taihang Mountains

为促进山坡产汇流过程的精细化模拟,以河北省易县崇陵流域典型的土石山区不同坡位点(坡顶、坡中上、坡中、坡中下、坡脚)以及不同植被(油松和侧柏)为研究对象,采用亮蓝染色剂开展了野外双环入渗染色剂示踪试验,研究了山坡壤中流汇流界面的变化规律及其影响因子。结果表明:(1)山坡壤中流汇流界面埋深介于0. 6～1. 5 m之间,从坡顶到坡脚,汇流界面厚度逐渐减小;(2)植被覆盖对壤中流汇流界面的影响很大,在相同的坡位处,侧柏的壤中流汇流界面厚度大于油松的壤中流汇流界面厚度;(3)汇流界面的影响因素主要是土壤的结构和孔隙性、岩石风化层的层次结构,植被通过改变土壤的孔隙性引起汇流界面的变化。

In order to promote the refined simulation of the runoff yield and confluence process of hillslope,the different slope positions(slope top,mid-up part of slope,mid-lower part of slope,slope toe)and different types of vegetation(Chinese pine and Platycladus orientalis)of the typical rocky mountainous area of Chongling Watershed in Yixian County of Herbei Province are taken as the study objects,and then the changing law and the influencing factors of the confluence interface of hillslope subsurface flow are studied herein through the field double loop infiltration dye tracing experiment made with brilliant blue coloring agent.The study result shows that(1)the buried depth of the confluence interface of subsurface flow of hillslope is about 0.6~1.5 m,while the thickness of the confluence interface gradually decreases from slope top to slope toe;(2)the confluence interface is greatly influenced by the vegetation coverage therein,while the thickness of the confluence interface of subsurface flow under Platycladus orientalis is larger than that under Chinese pine at the same slope position;(3)the main factors to influence the confluence interface are soil structure,porosity and the hierarchical structure of rock weathering layer,moreover,the variation of the confluence interface is caused by vegetation coverage through changing the porosity of soil.