摘要
荒草地是黄河班多水电站工程区最主要的原生地面类型,阐明其产流产沙的水流含沙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,研究了黄河班多水电站工程区荒草地坡面水流含沙量变化过程。结果表明:坡面水流含沙量随时间的变化,不同供水流量下整体减小,最后趋于稳定变化的趋势,可用幂函数方程很好的描述;不同坡度下也整体呈减小的趋势,15min后趋于平缓稳定变化的状态,各坡度下变化趋势大体一致,也可用幂函数方程很好的描述,与不同供水流量下的主要差异在于产流后5min内含沙量递减速率大于不同供水流量下的,其后递减速率小于不同供水流量下的;平均含沙量随供水流量的变化可用抛物线相关方程来描述,发生变化的临界供水流量值为7.388 5L/min,随坡度的增大而增大,可用指数方程很好的描述,随坡度及供水流量的变化可用二元线性方程很好的描述。
Waste grassland is the main primary land type in the construction area of Banduo hydropower station of the Yellow River. Elucidating variations of sediment concentrations in water flow in the processes of runoff and sediment yield may provide an important basis for the quantitative evaluation of soil and water loss in the area. The variations of sediment concentrations over waste grassland were studied by a field scouring experiment conducted in the construction area of Banduo hydropower station of the Yellow River. Results showed that in the case of different added discharges, sediment concentration varies with added water discharge and manifests a trend of the overall decrease and eventual steady sate, which can be well described by using a power equation. At different slope degrees, sediment concentration also shows an overall decrea sing trend and finally approaches to a steady state in 15 min after water is added. The variations of different slope ly, a grees degrees are basically consistent and can be also well described by using a power equation. Comparatively, a major difference is that the decreased rate of sediment concentration in the case of different slope degrees is greater that in the case of different discharges 5 min after runoff generated and later on, less than that in the case of different discharges. The variation of the average sediment concentration with added discharge can be well described found to be 7. 388 5 L/min. which can be well described with slope degree and added by using a parabolic equation and the critical discharge for an abrupt change is The average sediment concentration increases rapidly with rise of slBpe degree, by an exponential equation. The variation of the average sediment conceritraition discharge can be well described by using a dual power equation.
出处
《水土保持研究》
CSCD
北大核心
2014年第2期72-75,81,共5页
Research of Soil and Water Conservation
关键词
黄河
班多水电站
工程区
荒草地
含沙量
Yellow River
Banduo hydropower station
construction area
waste grassland
sediment Concentration
