泥沙来源“指纹”示踪技术研究综述

A review of studies on catchment sediment sources discrimination with fingerprinting techniques

泥沙来源"指纹"示踪技术是综合研究流域土壤侵蚀和泥沙输移的新方法。泥沙来源"指纹"示踪技术基于流域侵蚀产沙过程划分潜在物源类型,根据物源特性筛选具有诊断能力的"指纹"性质,通过定量转换模型建立流域出口泥沙与内部潜在物源间的"指纹"联系,定量描述各潜在物源对流域出口产沙的相对贡献;结合悬移质或沉积泥沙通量监测,定量分析各潜在物源对流域产沙的绝对贡献量及流域侵蚀产沙时、空变化特征。通过综述泥沙来源"指纹"示踪技术的理论基础及实施框架,流域尺度潜在物源类型,泥沙"指纹"因子类别、分布特点及诊断能力,泥沙来源复合"指纹"示踪技术的研究进展,指出泥沙来源"指纹"示踪技术的局限性,并对泥沙来源"指纹"示踪技术进行展望。

Sediment sources discrimination with fingerprinting procedures has been established as a novel technique in investigating catchment soil erosion and sediment redistribution.Within-catchment potential sediment sources were initially identified and classified according to catchment-specific soil erosion and sediment redistribution characteristics,sediment fingerprints with source-specific diagnostic ability were then selected and analyzed according to the previously determined source types,and the relative contributions of potential sediment sources to sediment yield at the catchment outlet can be quantitatively differentiated by establishing the fingerprint link between mixed sediment samples and source materials.Furthermore,combined with suspended or deposited sediment flux monitoring,sediment load at catchment outlet contributed by specific sediment source type can be quantitatively determined and the spatiotemporal variance of soil erosion and sediment export in a catchment can be explicitly understood.The present paper reviewed the theoretical basis of the fingerprinting technique and implementing framework of fingerprinting procedures,potential sediment source types,categories,distribution pattern and diagnostic ability of sediment fingerprints,and development of composite fingerprinting.Finally,limitations and prospects associated with sediment fingerprinting were analyzed and discussed.