土壤学报2024，Vol.61Issue(6)：1492-1505,14.DOI:10.11766/trxb202306270248
基于REE示踪对红壤细沟间侵蚀团聚体周转和泥沙迁移特征的研究
Characteristics of Aggregate Turnover and Sediment Transport by Interrill Erosion Using Rare Earth Elements in Red Soil
摘要
Abstract
Soil aggregates are the basic unit of soil structure and the particle size distribution of surface aggregates play an important role in soil structure and erosion process development.[Objective]Therefore,the purpose of this study was to explores the mutual transformation of soil aggregates of different particle sizes and the sediment migration path during the interrill erosion and quantify the source characteristics of eroded sediment.[Method]In this study,a quaternary red clay was collected from Xian'ning in Hubei Province of China,and the soil aggregates were labeled by the rare earth tracer method.Under the condition of 90 mm·h-1 rainfall intensity,the laboratory simulated rainfall experiment was conducted based on a miniature soil trough with the slope set at 10°.Sediment samples were collected at an interval of 6 min after steady flow production during rainfall,and the contents of rare earth elements in the samples were determined by ICP-MS.A quantitative characterization was also performed on the transformation of soil aggregates within different particle sizes(5-2 mm,large macroaggregates;2-0.25 mm,small macroaggregates;0.25-0.053 mm,microaggregates;and<0.053 mm,silt and clay fractions)and the source characteristics of erosion sediment under the Rare Earth Element(REE)concentration.[Result]The results show that the eroded sediment particles were mainly formed by the same size aggregates transported by runoff,and the content of the sediment particles with the increase of rainfall time.The residual aggregates showed an obvious turnover process and the aggregates with size<0.25 mm were more easily adsorbed to the aggregates with large size,while the aggregates with size>0.25 mm tended to be broken(the fragmentation rate reached 45.8%and 43.3%),and the broken degree of soil aggregates increased continuously.The characteristics of sediment yield were closely related to the change in topsoil structure and sediment migration and the sediment content of<0.053 mm and 2-0.25 mm and the contribution rate of the corresponding aggregates in sediment played an important role in the fractal dimension of runoff coefficient and sediment particle size.For the characteristics of erosion sediment production,the sediment content of<0.053 m and 2-0.25 mm and the contribution rate of the corresponding aggregates in the sediment played an important role in the runoff coefficient and the fractal dimension of sediment particle size.[Conclusion]Thus,the change of soil topsoil structure and the characteristics of sediment loss during interrill erosion are closely related to aggregate particle size.This further deepens the dynamic process of the interrill erosion and provides a theoretical basis for the soil erosion model and soil and water conservation measures.关键词
红壤/人工模拟降雨/REE示踪法/团聚体周转/细沟间侵蚀Key words
Red soil/Artificially simulated rainfall/REE tracer method/Aggregate turnover/Interrill erosion分类
农业科技引用本文复制引用
张晨阳,杨伟,汪零,彭珏,王军光,蔡崇法..基于REE示踪对红壤细沟间侵蚀团聚体周转和泥沙迁移特征的研究[J].土壤学报,2024,61(6):1492-1505,14.基金项目
国家自然科学基金项目(42177317)和湖北省大别山区典型小流域次降雨水土流失预报模型研究项目(HBSLKY202304)资助Supported by the National Natural Science Foundation of China(No.42177317)and the Study on Sub-rainfall Erosion Forecasting Model for Typical Sub-watersheds in Dabie Mountainous Area of Hubei Province(No.HBSLKY202304) （42177317）
