不同尺度下冻融作用对东北黑土区产流产沙的影响

发布时间：2018-03-13 21:41

本文选题：冻融　切入点：径流小区　出处：《水土保持学报》2017年05期 　论文类型：期刊论文

【摘要】：通过对东北黑土区坡面8年和小流域7年的降雨产流产沙过程观测,对比每年受冻融作用影响的降雨和其余不受冻融作用影响的降雨产流产沙的特征,研究冻融作用在坡面和小流域尺度上对东北黑土区产流产沙的影响,为东北黑土区在冻融作用下多尺度土壤侵蚀定量评价及其转换模型的建立提供科学依据。结果表明:冻融作用减小了坡面和小流域的产流,径流系数分别减小0.07和0.03,坡面产流延迟71.7%,而小流域无明显延迟。坡面和小流域土壤流失量、土壤可蚀性K值及含沙量均显著增加,更易在较小降雨侵蚀力下产生较大流失量;与不受冻融的降雨事件相比,受冻融影响的降雨事件因径流减弱,在相同降雨量下的侵蚀量低,而在相同径流深下的侵蚀量高。冻融作用在径流较小时对坡面细沟的发育及产沙影响明显,在径流较大时对小流域切沟中松散堆积物的搬运及产沙影响明显。
[Abstract]:Based on the observation of precipitation and sediment yield in black soil region of Northeast China for 8 years and 7 years in small watershed, the characteristics of precipitation affected by freeze-thaw are compared with those of other rainfall that are not affected by freezing and thawing. The effects of freezing and thawing on runoff and sediment production in black soil region of Northeast China on slope and small watershed scale were studied. It provides a scientific basis for quantitative evaluation of multi-scale soil erosion and the establishment of transformation model under freeze-thaw action in the black soil region of Northeast China. The results show that freeze-thaw process reduces runoff generation on slope and small watershed. Runoff coefficient decreased 0.07 and 0.03, runoff production delay was 71.7, but there was no obvious delay in small watershed. Soil loss amount, soil erodibility K value and sediment content increased significantly in slope and small watershed. Compared with the rainfall events without freezing and thawing, the rainfall events affected by freeze-thaw are weakened by runoff, and the amount of erosion under the same rainfall is lower. The effect of freeze-thaw on the development and sediment yield of sloping gully is obvious when the runoff is small, and the transport and sediment yield of loose accumulation in the gully is obvious when the runoff is large.
【作者单位】：北京师范大学地理科学学部地理学院;北京师范大学地理科学学部地表过程与资源生态国家重点实验室;
【基金】：国家自然科学基金项目(41471224)
【分类号】：S157.1

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