CAJ | 학술논문

为了探究前期含水率对南方红壤团聚体稳定性及溅蚀的影响，选取泥质页岩和第四纪红黏土发育的4个典型红壤为研究对象，就5个前期含水率（3%、5%、10%、15%、20%）条件下3～5 mm团聚体水稳定性特征及其与溅蚀的关系进行了初步的探讨。结果表明，消散作用是团聚体破碎最有效的机制，土壤前期含水率越大，团聚体破碎程度越小。随着前期含水率的升高，泥质页岩发育的2种红壤水稳性团聚体平均质量直径（MWDwa）显著增大；第四纪红黏土发育的2种红壤水稳性团聚体平均质量直径（MWDwa）先增大后减小，拐点出现在含水率为15%条件下。泥质页岩发育2种红壤溅蚀量随前期含水率的升高显著减小；第四纪红黏土发育2种红壤溅蚀量随前期含水率的升高呈现先减小后增大的趋势，在含水率为15%时达到最小。团聚体水稳性较高的土样，溅蚀粒径分布呈双峰曲线分布，主要分布1～0.5和<0.05 mm范围内，且前期含水率越高，<0.05 mm溅蚀颗粒含量越大；而团聚体水稳定性较差的土样，除前期含水率为20%外，溅蚀粒径分布呈单峰曲线分布，主要分布在0.25～1mm。该结果为红壤区农业水土工程及机侵蚀机理研究提供一定的参考，对完善坡面水蚀模型具有一定的参考价值。
위료탐구전기함수솔대남방홍양단취체은정성급천식적영향，선취니질혈암화제사기홍점토발육적4개전형홍양위연구대상，취5개전기함수솔（3%、5%、10%、15%、20%）조건하3～5 mm단취체수은정성특정급기여천식적관계진행료초보적탐토。결과표명，소산작용시단취체파쇄최유효적궤제，토양전기함수솔월대，단취체파쇄정도월소。수착전기함수솔적승고，니질혈암발육적2충홍양수은성단취체평균질량직경（MWDwa）현저증대；제사기홍점토발육적2충홍양수은성단취체평균질량직경（MWDwa）선증대후감소，괴점출현재함수솔위15%조건하。니질혈암발육2충홍양천식량수전기함수솔적승고현저감소；제사기홍점토발육2충홍양천식량수전기함수솔적승고정현선감소후증대적추세，재함수솔위15%시체도최소。단취체수은성교고적토양，천식립경분포정쌍봉곡선분포，주요분포1～0.5화<0.05 mm범위내，차전기함수솔월고，<0.05 mm천식과립함량월대；이단취체수은정성교차적토양，제전기함수솔위20%외，천식립경분포정단봉곡선분포，주요분포재0.25～1mm。해결과위홍양구농업수토공정급궤침식궤리연구제공일정적삼고，대완선파면수식모형구유일정적삼고개치。
Rainfall splash erosion, usually the first step in soil loss and sediment transport, is a critical process in hillslope water erosion. It is recognized that antecedent moisture content influences the re-aggregation of soil particles and their subsequent enhanced ability to resist exogenic soil erosional forces. The purpose of this study was to determine the effect of antecedent moisture on aggregate stability and splash for Utisols in subtropical China. Four soil samples derived from Shale and Quaternary red soil and five antecedent moisture contents (3 %, 5 %, 10 %, 15 %, and 20 %) were tested in this study. Effects of antecedent moisture on aggregate stability and splash erosion were discussed based on the analysis of aggregate water stability using wet-sieving method and rainfall simulation with an intensity of 60 mm/h for 45 minutes in laboratory. Mean weight diameter of aggregate water stability (MWDwa) was used as the aggregate stability index. The fragments splashed out were measured by wet sieving with sieves of 2.0 mm, 1.0 mm, 0.5 mm, 0.25 mm, respectively. And fragments less than 0.25 mm in size were then measured by a laser diffraction sizer in five classes (0.2-0.25 mm, 0.15-0.2 mm, 0.10-0.15 mm, 0.05-0.10 mm, and < 0.05 mm). The results showed that aggregate water stability significantly increased with increasing antecedent moisture content and slaking was the most efficient breakdown mechanism. With the increase of antecedent moisture content, MWDwa values of the soils derived from Shale significantly increased. However, the MWDwa values of soils derived from Quaternary red clay increased initially then decreased, with the most stable value at the moisture of 15%. With antecedent moisture content increasing, the total mass of splash for soils derived from Shale decreased, but decreased first then increased for soils derived from Quaternary red clay, with a minimum value at the moisture of 15%. The size-selectivity was determined by the size distribution and surface structure at different antecedent moisture contents. For more stable soils, size distribution of the splashed fragments is bimodal with a major peak at 1-0.5 mm and < 0.05 mm. For less stable soils, size distribution of splashed is unimodal with a large peak at 1-0.25 mm except the ones at the moisture of 20 %. The results can provide a reference for agricultural water-soil engineering and water erosion mechanisms of Utisols, which has great significance for improving soil erosion models.