Research On The Characteristic Of Soil Erosion Energy In The Loess Plateau

Globally and nationally the process of soil erosion has become a serious issue. As well known, the Loess Plateau is the strongest erosion region. Water erosion is the main form of soil erosion in there. So studying water erosion and probing the laws of sediment yield, have significant production practice meaning to the prevention and cure for soil erosion and all kinds of silt disaster. In the paper, we firstly acknowledge the characteristic of rainfall kinetic energy and runoff energy , current state and the development of erosion dynamic process by consulting a large number of domestic and foreign literature datum. On the basic, we systemically coordinated the eroded datum of runoff plots of soil and water conservation stations at Xifeng, Tianshui, Suide, and Chunhua et al. Applied the principle and method of soil erosion, soil erosion mechanics, soil science, mathematical statistics, hydrology, and soil and water conservation method, we evaluate the energy formula of domestic and international in the Loess Plateau used. Analyzed the research district soil erosion energy characteristic. The primarily results were displayed as follows:1 .Through statistical analyzing the relativity of erode rainfall kinetic energy and soil erosion quantity, we elected the suitable energy formula used in the Loess Plateau.2. The maximum of rainfall kinetic energy was 2750.48 J/m2, and the maximum runoff energy was 846.86 J/m2 in study district. Soil erosion was extremely serious by high intensity storm with high rainfall energy. The correlation of erosion quantity with rainfall energy and runoff energy is linear through regression.3.Through analyzing the erosion energy characteristic of different rainfall capacity, rainfall duration, and runoff depth classes, we draw that rainfall kinetic energy and runoff energy presented positive correlation with the rainfall duration. And presenting the fluctuation change with extension that rainfall duration; runoff energy increase with increase of runoff depth.4.Through statistical analyzing the eroded rainfall datum of sloping field runoff plots as gradient from 10 to 28 , we get the standard of eroded rainfall is Ea =171.87J/m25. Analyzing the different vegetation cover rate of impact on runoff energy, we draw the cutting rate for runoff energy would increase with the vegetation cover rate increased. And the cutting rate to runoff energy is falling with rainfall energy increased. Through regression, we found runoff energy cut rate present logarithm relevant to rainfall energy.6. When the rainfall frequency was 83.11% that belong to low energy of rainfall,vegetation cover rate that was bigger than 80% can totally diminish runoff energy, and prevent soil erosion. With eroded rainfall energy increasing the cut rate of vegetation for erosion gradually weak. In order to prevent high-energy storm erosion we not only need augment the vegetation cover rate but also need soil conservation project measure.