Study On The Effect And Mechanism Of The Slope Runoff Regulation

Drought, water shortage and soil and water losses are major factors to limit economic and social sustainable development in the arid and semi-arid region. Runoff is not only drive of producing soil and water erosion, but also the important water source of abating drought and shortage water. Therefore, scientific regulation and utilization of runoff is the effect and essential way to control soil erosion and abating drought and shortage water. Based on the theory of runoff regulation as research guide, and with the combination of scouring water experiment in the slope and artificial simulation experiment, this paper studied the process of the surface runoff production and change, analyzed effects of different runoff regulation measurements on soil storage water and runoff and sediment reduction. Additionally, the paper discussed mechanism of regulating runoff and sediment using flow hydraulics, dynamics, and resistance and topsoil microstructure. Main results are shown as follows:1. The process of producing runoff and sediment in un-regulation measurement slope was special. Intensity of producing runoff shows a trend of increasing abruptly initially, reducing subsequently and finally presenting steady with scouring water duration, there is a good logarithm relationship between them.2. The effects of different regulation measurements on runoff and sediment yield have the significant differences. Due to plant vegetation's obstruction and separation for flow and water absorption of root, surface storage regulation measurements shows the relative steady runoff production rater and sediment yield rater, however, runoff production time reduced 5.9min under maximal flow from 18.0min under minimal flow. Surface water conservation regulation measurement blocks flow and intensifies infiltration. Only minim erosion was produced and runoff production time was 17.6min under 2.5m~3/h. Point regulation measurement distributes runoff production and influx and play important role in transverse blocking for the lengthways runoff, the process of runoff sediment increases preliminary and decreased subsequently within 3.0m~3/h, otherwise, the process shows unstable due to flow erosion, soil destruction.3. Soil water content in the 0-150cm section layer fluctuates greatly not only regulation slope also regulation slope. The fluctuation of soil water content in the up-layer results from runoff fluctuation and variations in the down-layer results from soil texture spatial change.