指纹因子和估算模型对复合指纹识别泥沙来源的影响

Influence of fingerprinting properties and estimation models on sediment source discrimination via composite fingerprinting approach

复合指纹识别法在泥沙与污染物来源辨别、侵蚀环境变化回溯、流域综合治理提升等方面发挥着重要作用。指纹因子和贡献估算模型作为复合指纹识别法的关键,对泥沙来源识别结果的准确性有重要影响。通过总结现行指纹因子组筛选方法、估算模型选用及其关键因子校正等相关研究成果,明确二者对泥沙来源识别结果的影响。结果显示,在分别采用不同指纹因子筛选方法和模型估算泥沙来源时,相同研究区同一源地的贡献差异可分别达到18.0%和14.2%。未来研究中,建议针对复合指纹识别的泥沙来源结果缺乏充分验证这一关键问题,以精准的泥沙来源数据为验证基础,通过科学试验结合多种技术手段,辨别复合指纹识别泥沙来源的主要不确定性来源。

[Background]The composite fingerprinting approach has been developed as one of the most important methods in sediment and contaminant source study,change tracing in erosional environment,and integrated management improvement of watersheds.Fingerprints and contribution estimation models are key aspects affecting the accuracy of sediment source identification,which further influence the tracing reliability of correlated contaminant source and erosional environment change,as well as the development of watershed management strategies.Thus,it is significant to understanding the impact of fingerprints and estimation models on sediment source.[Methods]This study summarizes research progress on the screening methods of fingerprints,selection of estimation models,and correction of key factors in models to clarify their impacts on the accurate identification of sediment sources using the composite fingerprinting approach.[Results]The selection of an optimal composite fingerprinting group or multiple composite fingerprinting groups had a significant impact on sediment source identification,which was also the case for the selection of different types of models.This was because fingerprints not only linked soil in source areas and deposited sediment,but also provided the basis for the selection of estimation models.Studies conducted in the same region suggested that sediment contribution from the same source varied up to 18.0%and 14.2%,respectively,when adopting different composite fingerprints selection methods and contribution estimation models.Thus,future research must enhance system study of the approach,and focus on solving the issue that previous studies lacked reliable validation of sediment source estimation using the composite fingerprinting approach through other reliable methods.It is urgent to obtain reliable and precise sediment source quantification data through scientific experiments using multiple techniques.Based on these precise verification data,further studies should first check and confirm the primary uncertainty sources affecting sediment source discrimination;second,select better fingerprints screening method;and third,improve contribution estimation models and algorithms of the key factors.[Conclusions]The ultimate objective is to improve the composite fingerprinting approach,and establish a normative methodology for the accurate quantification of sediment sources to serve the reasonable design of soil water conservation measures.