黄河班多水电站荒草地坡面侵蚀过程试验研究

Experimental Study of Erosion Processes on Waste Grassland in Banduo Hydropower Station of Yellow River

荒草地是黄河班多水电站工程区最主要的原生地面类型,阐明其侵蚀过程可为该工程区水土流失定量评价提供重要依据。采用野外人工放水冲刷试验方法,分析研究了黄河班多水电站工程区原生地面荒草地在不同供水流量和坡度下的坡面侵蚀规律。结果表明:坡面侵蚀率在不同供水流量下和不同坡度下都表现为整体呈减小的趋势,以后趋于相对稳定。可分别用对数方程和幂函数方程描述,两者区别主要为不同坡度下,坡面侵蚀率在产流后5min内下降很快,随后减小率下降,而不同供水流量15min内递减的速率很快;坡面侵蚀模数随供水流量及坡度的增大皆增大,同时都可用指数方程很好地描述;供水流量及坡度对坡面侵蚀模数的综合影响可用二元幂函数方描述。

Waste grassland is the main primary land type in the construction area of Banduo hydropower station of the Yellow River. Exploring its erosion process may provide an important basis for the quantitative evaluation of soil and water loss in the area. Based on field scouring experiment, the erosion processes of waste grassland in the Banduo hydropower station project area in the Yellow River are studied and following results are obtained. Both the erosion rates under different slopes and different water supply discharge show overall decrease trend and finally reach relative stability, which can be described through logarithmic equation and power equation, respectively. The main difference between them is that under different slope, the erosion rate falls rapidly after 5 minutes of runoff and then the decrease rate become slower, while under different water supply discharges, it falls rapidly in 15 minutes; the erosion modulus increases with the slope and water supply discharge, an exponential equation can be used to describe the trend. While a dual power equation can be used for the description of combined effects of both factors.