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通过室内模拟降雨试验,研究不同降雨强度下,不同坡度片麻岩坡面土壤侵蚀和养分流失特征。结果表明:初始产流时间与坡度之间呈明显的负相关;不同坡度对坡面产流率产沙率变化过程影响不大。通过比较不同坡度片麻岩坡面(5°,15°,25°)在降雨强度分别为60mm/h和80mm/h时的产沙量,发现坡度对坡面产沙的贡献率相对较小,分别为0,16.3%和8.1%,而雨强因子在坡面侵蚀产沙中占主导作用。在相同降雨条件下,15°坡面上径流深度、累积产沙量和养分流失量均表现为最大,即片麻岩坡面的径流流失在15°~25°间存在临界坡度。片麻岩坡面氮、磷、钾的流失主要以泥沙结合态为主,尤其是磷和钾的流失,钾的累积流失量最大,其次是氮,磷流失量最小。
Through indoor simulated rainfall experiment, the characteristics of soil erosion and nutrient loss on gully slope with different gradient under different rainfall intensity were studied. The results show that there is a significant negative correlation between initial runoff time and slope. Different slope has little effect on the rate of runoff and sediment yield. By comparing the sediment yield at different slopes of gneiss (5 °, 15 °, 25 °) with rainfall intensities of 60 mm / h and 80 mm / h respectively, it is found that the contribution of slope to sand production is relatively small , Respectively, 0,16.3% and 8.1%, while the rainy area factor plays a dominant role in slope erosion and sediment yield. Under the same rainfall conditions, runoff depth, accumulated sediment yield and nutrient loss on the 15 ° slope were the highest, that is, there was a critical gradient of runoff loss on the gneiss slope from 15 ° to 25 °. The loss of nitrogen, phosphorus and potassium in the gneiss slope is dominated by sediment-bound species, especially the loss of phosphorus and potassium, with the largest accumulation of potassium, followed by the smallest of nitrogen and phosphorus losses.