模拟降雨下不同坡度土壤坡面产流产沙特征及磷和钾素流失研究

发布时间：2018-05-08 21:26

本文选题：模拟降雨 + 土壤坡度　；参考：《水土保持研究》2017年02期

【摘要】：采用室内模拟降雨研究了不同坡度对土壤坡面产流产沙特征及其养分流失的影响。结果表明:在降雨条件下,初始产流时间随坡度的增加而趋于提前,初始产流时间变化范围为0.63~1.62min,说明坡面产流时间因坡面坡度的增加而缩短。不同坡度条件下径流强度随降雨历时的增加而增加,在降雨历时前20min,径流强度急剧增加,降雨历时20min以后,径流强度增加趋势趋于平稳,径流强度遵循幂函数变化规律;不同坡度条件下入渗强度随降雨历时的增加而降低,在降雨历时前20min,入渗强度急剧降低,降雨历时20min以后,入渗强度降低趋势趋于平稳,坡面入渗强度随时间则呈对数函数变化。不同坡度下径流量均随降雨历时呈"增加—稳定"趋势(单峰曲线,抛物线规律),在整个降雨过程中,径流量随坡度的增加而增加,在0~20min内,径流量随降雨历时的增加陡然上升趋势,20~40min,不同坡度条件下土壤泥沙侵蚀量均达到最大值,40min以后泥沙侵蚀量随降雨历时的增加呈现基本平稳趋势,泥沙侵蚀量中DP,K+,SEP和SEK均随着坡度的增加而增加。不同坡度条件下,泥沙量与侵蚀泥沙中养分的含量均存在不同程度的正相关关系,其中坡面坡度为20°,25°和30°时,侵蚀泥沙养分含量与泥沙流失量间的相关性明显优于其他坡度,说明侵蚀泥沙量的增加会引起泥沙中各种类养分含量的增加效应,而随着坡度的增加,侵蚀泥沙量与侵蚀泥沙中养分的含量并非均显示出更进一步的相关性。
[Abstract]:The effects of different slopes on the characteristics of runoff and sediment yield and nutrient loss on soil slope were studied by simulated rainfall in laboratory. The results show that the initial runoff yield time tends to advance with the increase of slope, and the change range of initial runoff yield time is 0.63 ~ 1.62 min, which indicates that the runoff production time on slope is shortened with the increase of slope degree. The intensity of runoff increases with the increase of rainfall duration under different slope conditions. The intensity of runoff increases sharply 20 minutes before the duration of rainfall. After rainfall duration of 20min, the increasing trend of runoff intensity tends to be stable, and the intensity of runoff follows the law of power function. Under different slope conditions, the infiltration intensity decreased with the increase of rainfall duration. 20 minutes before rainfall duration, the infiltration intensity decreased sharply, and after rainfall duration 20min, the trend of infiltration intensity decreased steadily. The infiltration intensity of slope varies with time as logarithmic function. Under different slopes, the runoff showed an "increasing-stable" trend with rainfall duration (single peak curve, parabola law). During the whole rainfall process, the runoff increased with the increase of slope, and in 0~20min, With the increase of rainfall duration, the runoff increased steeply for 20 ~ 40 min, and the soil sediment erosion reached the maximum value under different slope conditions. After 40 min, the soil sediment erosion showed a stable trend with the increase of rainfall duration. In sediment erosion, both DPK SEP and SEK increased with the increase of slope. Under different slope conditions, there is a positive correlation between sediment amount and nutrient content in eroded sediment to varying degrees. When the slope is 20 掳~ 25 掳and 30 掳, the correlation between soil nutrient content and sediment loss is better than that of other slopes. The results show that the increase of the amount of erosion sediment will lead to the increasing effect of various kinds of nutrients in sediment, but with the increase of slope, the amount of erosion sediment and the content of nutrients in erosive sediment do not show further correlation.
【作者单位】：黄河水利职业技术学院;河北省子牙河河务管理处;
【基金】：国家自然科学基金—河南省人才培养联合基金项目(U1304503) 河南省高等学校青年骨干教师资助计划资助项目(2011GGJS-188)
【分类号】：S157

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