The duration of rainfall is a significant factor in the process of splash erosion. Nevertheless, there is a lack of comprehensive documentation regarding the extent and characteristic of soil aggregate disintegration resulting from raindrop impact during splash erosion. To examine the properties of the aggregate disintegration mechanism during various of splash erosion, three soil samples (S‐1, S‐2, and S‐3 labeled as the organic matter was 19.77, 31.70, and 26.83 g kg−1) were employed to simulated splash erosion under six durations of rainfall (5, 10, 15, 20, 30, and 40 min). Aggregates ranging in size from 1 to 5 mm were utilized in the preparation of test soils for different antecedent moisture contents (3%, 5%, 10%, and 15%). The result demonstrated that the slaking effect, as observed in the fast wetting of the Le Bissonnais method, is attributed to the sudden release of air entering the water, irrespective of the water immersion duration. Upon increasing moisture content, under fast wetting conditions, the mean weight diameter (MWD) values for S‐2 and S‐3 samples increased from 1.25 and 1.31 to 1.85 and 1.61, respectively. Subsequently, at a moisture content of 10%, the MWD decreased to 1.84 and 1.49 for S‐2 and S‐3 samples, respectively. In contrast, S‐1 sample exhibited an increasing trend from 0.34 to 0.93. The sensitivity of aggregates to disintegration from slaking (RSI) decreased by 0.58, 0.43, and 0.29, while mechanical impact (RMI) decreased by 0.23, 0.11, and 0.08 with increasing moisture content, respectively. The rate of splash erosion for the S‐1 sample exhibited an initial increase followed by a subsequent decrease as the duration of rainfall increased. The S‐1 sample, with the lowest organic matter content, exhibited the highest content of microaggregate content (< 0.25 mm) of splashed particles (referring to soil particles transported out of the splash area by raindrops), ranging from 31.62% to 65.57%. The content of macroaggregate (> 0.25 mm) in the residual soil (indicating soil particles that were left in the area affected by splashing) exhibited a gradual reduction as the duration of rainfall increased. As the soil reached saturation, the influence of physicochemical dispersion became more pronounced with the prolonged duration of rainfall. The forces of slaking and physicochemical dispersion predominantly disrupted > 1 mm aggregates, while the destruction of aggregates within the 0.25–1 mm range was insufficient. This study is valuable for understanding the splash erosion process and provides a scientific foundation for the improvement of soil erosion prediction models.

中文翻译：

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不同情况下飞溅侵蚀过程中土壤团聚体崩解的变化性


降雨的持续时间是飞溅侵蚀过程中的一个重要因素。然而，关于飞溅侵蚀过程中雨滴撞击导致土壤团聚体崩解的范围和特征，缺乏全面的文献记录。为了检查各种飞溅侵蚀过程中团聚体崩解机制的特性，采用三个土壤样品 （S-1、S-2 和 S-3，标记为有机质为 19.77、31.70 和 26.83 g kg-1） 来模拟六种降雨持续时间 （5、10、15、20、30 和 40 分钟） 下的飞溅侵蚀。使用大小从 1 到 5 毫米不等的骨料来制备不同先前含水量（3%、5%、10% 和 15%）的测试土壤。结果表明，在 Le Bissonnais 方法的快速润湿中观察到的熟化效应归因于进入水中的空气的突然释放，而与浸水时间无关。随着水分含量的增加，在快速润湿条件下，S-2 和 S-3 样品的平均重量直径 （MWD） 值分别从 1.25 和 1.31 增加到 1.85 和 1.61。随后，在水份含量为 10% 时，S-2 和 S-3 样品的 MWD 分别下降到 1.84 和 1.49。相比之下，S-1 样品表现出从 0.34 到 0.93 的增加趋势。随着含水率的增加，团聚体对解体的敏感性 （RSI） 降低了 0.58 、 0.43 和 0.29，而机械冲击 （RMI） 分别降低了 0.23 、 0.11 和 0.08。S-1 样品的飞溅侵蚀速率最初呈增加，然后随着降雨持续时间的增加而下降。 有机质含量最低的 S-1 样品中飞溅颗粒（指雨滴运出飞溅区的土壤颗粒）的微团料含量最高（< 0.25 mm），范围为 31.62% 至 65.57%。随着降雨持续时间的增加，残余土壤中大团聚体的含量 （> 0.25 mm） （表示留在受飞溅影响区域的土壤颗粒） 逐渐减少。随着土壤达到饱和，随着降雨持续时间的延长，物理化学分散的影响变得更加明显。崩解力和物理化学分散力主要破坏了 > 1 mm 的聚集体，而对 0.25-1 mm 范围内的聚集体的破坏是不够的。本研究对理解水花侵蚀过程具有重要价值，为改进土壤侵蚀预测模型提供了科学依据。