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通过室内模拟降雨试验,研究降雨强度对太行山区片麻岩坡地产沙产流和养分流失的影响,结果表明:初始产流时间与雨强具有明显的负相关;不同雨强对坡面累积产流产沙影响较大,随雨强的增大,径流量和泥沙量也呈现增大的趋势。在整场降雨过程中,产流率呈现出先增加,到达峰值后产流率趋于稳定不再继续增大,不同雨强片麻岩坡面(60,80,100mm/h)的产流率达到的峰值分别为1 068,2 930,3 019ml/min;泥沙浓度在整场降雨中表现为先降低然后趋于稳定,比较不同雨强片麻岩坡面(60,80,100mm/h)的产沙量为351.49,2 882.33,3 613.23g,发现雨强对坡面径流的影响较大。坡面养分流失主要以泥沙结合态为主,泥沙态养分所占比例达到98%以上,并随雨强增大,泥沙态含量也随之增加,坡面氮素流失在雨强较小时养分流失方式为溶解态氮和泥沙态氮共同作用,随着雨强增加,泥沙态所占比例增大到92%,94%。径流流失的总养分量(总氮、总磷和总钾)与雨强之间具有正相关性,整场降雨过程中水样氮浓度随降雨历时增加呈下降趋势;泥沙中养分随时间变化波动较大,没有反映出与雨强的相关性。
Effects of rainfall intensity on sediment yield and nutrient loss in the gneisal slope of Taihang Mountains were studied by indoor simulated rainfall test. The results showed that the initial runoff time was significantly negatively correlated with rainfall intensity. The effect of abstraction sediment is larger. With the increase of rainfall intensity, the runoff and sediment also show an increasing trend. During the entire rainfall, the rate of flow increased first, and the rate of flow rate stabilized after reaching the peak no longer continued to increase. The flow rate of the different rainfall gneiss slopes (60,80,100mm / h) reached The peak values of sediment concentration were 1 068, 2 930 and 3 019 ml / min, respectively. Sediment concentration decreased firstly and then stabilized in the whole rainfall. The sediment yield was 351.49,2882.33,3613.23g. It was found that the rainfall intensity had a great influence on runoff. Nutrient loss on slope was dominated by sediment-bound species, with the proportion of sediment-state nutrients reaching more than 98%. With the increase of rainfall intensity, the content of sediment-state also increased. The nutrient loss pattern of hour is the interaction of dissolved nitrogen and sediment nitrogen, with the increase of rainfall intensity, the proportion of sediment increased to 92%, 94%. There was a positive correlation between total nitrogen loss (total nitrogen, total phosphorus and total potassium) and rainfall intensity during runoff loss. During the whole rainfall, the nitrogen concentration in water samples showed a decreasing trend with increasing rainfall duration. Nutrients in sediment changed with time Fluctuations, did not reflect the strong correlation with the rain.