Wu Feng-Zhi, Shi Zhi-Hua, Fang Nu-Fang, Yue Ben-Jiang
State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling 712100, China.
Huan Jing Ke Xue. 2012 Jul;33(7):2497-502.
Erosion and sediment characteristics were measured using simulated rainfall on two cultivated soils from the Loess Plateau, China. The size distribution of eroded sediment (non-dispersed) was compared with equivalent measurements of the same samples after chemical and mechanical dispersion(dispersed) to investigate the aggregation ratio (AR) and enrichment ratio (ER). Results show that clay content is increasing with the length and rainfall intensity. The loessial soil increased by 8.77% and 2.43%, but the Lou soil increased by only 2.76% and 0.4%. With the increase of slope, the clay content of the two loess reduced by 4.91% and 3.93%, respectively. AR values were less than 1 and ER values were greater than 1. These indicated that relatively slight clay dispersion occurred and that most of the clay in the sediments was in the form of aggregates. The results will improve understanding of erosion and sedimentation processes, which in turn will improve erosion modeling. Knowledge of temporal variations of clay in sediment can also provide the basis for understanding and modeling the transfer of nutrients on hillslope.
利用模拟降雨对中国黄土高原的两种耕作土壤的侵蚀和泥沙特性进行了测量。将侵蚀泥沙（未分散）的粒径分布与化学和机械分散（分散后）相同样品的等效测量结果进行比较，以研究团聚比（AR）和富集比（ER）。结果表明，黏土含量随降雨历时和降雨强度的增加而增加。黄土土样分别增加了8.77%和2.43%，但塿土样仅增加了2.76%和0.4%。随着坡度的增加，两种黄土的黏土含量分别降低了4.91%和3.93%。AR值小于1，ER值大于1。这表明发生了相对轻微的黏土分散，且沉积物中的大部分黏土呈团聚体形式。这些结果将增进对侵蚀和沉积过程的理解，进而改进侵蚀模型。了解沉积物中黏土的时间变化也可为理解和模拟山坡上养分的转移提供依据。
