坡面侵蚀过程中泥沙有机碳流失特征分析

发布时间：2019-03-15 15:30

【摘要】：以野外布设的径流小区为研究对象,采用模拟降雨方法研究随机条件下降雨侵蚀过程中泥沙有机碳含量及流失过程的动态变化规律。结果表明:(1)降雨侵蚀过程中泥沙有机碳含量随降雨的进行逐渐降低并趋于平稳,与坡面土壤有机碳含量相比显著增高(p0.01),有机碳在泥沙中明显富集,富集比最大值达1.780,泥沙中有机碳含量及富集比随侵蚀速率的增加明显减小且趋于稳定;(2)泥沙有机碳流失速率随降雨的进行先波动增大,达到最大值后又波动减小,最后逐渐趋于准稳定,整个过程呈单峰分布;(3)泥沙有机碳流失强度与土壤侵蚀强度呈显著性线性正相关(p0.01),说明土壤侵蚀量决定侵蚀过程中有机碳流失量,准确获取土壤侵蚀强度是估算坡面有机碳流失量的基础。
[Abstract]:A simulated rainfall method was used to study the dynamic variation of sediment organic carbon content and loss process in the process of rainfall erosion under random conditions, taking the runoff plot set up in the field as the research object. The results are as follows: (1) the organic carbon content of sediment decreases gradually and tends to be stable with rainfall, which is significantly higher than that of slope soil (p0.01), and the organic carbon is enriched in sediment. When the maximum enrichment ratio is 1.780, the organic carbon content and enrichment ratio in sediment decrease obviously and tend to be stable with the increase of erosion rate. (2) the rate of sediment organic carbon loss increases first with rainfall, reaches the maximum value and then decreases, then tends to quasi-stable gradually, and the whole process shows a single peak distribution; (3) there was a significant positive linear correlation between soil erosion intensity and sediment organic carbon loss intensity (p0.01), indicating that the amount of soil erosion determined the amount of organic carbon loss in erosion process, and there was a significant positive correlation between erosion intensity and soil erosion intensity (p0.01). Accurately obtaining soil erosion intensity is the basis for estimating the loss of organic carbon on slope surface.
【作者单位】：西北农林科技大学水土保持研究所黄土高原土壤侵蚀与旱地农业国家重点实验室;中国科学院水利部水土保持研究所;
【基金】：国家重点研发计划项目(2016YFC0402406) 国家自然科学基金项目(41571130082,41371283,41671281)
【分类号】：S157.1

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