کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5116916 1485221 2017 15 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Use of sediment source fingerprinting to assess the role of subsurface erosion in the supply of fine sediment in a degraded catchment in the Eastern Cape, South Africa
ترجمه فارسی عنوان
استفاده از اثر انگشت منبع رسوب برای ارزیابی نقش فرسایش زیر سطح در تامین رسوبات خوب در یک کانال تخریب شده در کیپ شرقی، آفریقای جنوبی
کلمات کلیدی
اثر انگشت منبع رسوب، تجزیه و تحلیل عدم قطعیت، کیپ شرقی فرسایش کوهی مدل سازی تعادل توده،
موضوعات مرتبط
مهندسی و علوم پایه مهندسی انرژی انرژی های تجدید پذیر، توسعه پایدار و محیط زیست
چکیده انگلیسی


- Model insensitive to number of properties entered and model iterations.
- Increasing model iterations did not change uncertainty ranges in source proportions.
- Large spread observed in the predicted sediment source proportions.
- Contributions from surface and subsurface sources were different in two proximal cores.
- Limitations of floodplain cores in sediment source fingerprinting were highlighted.

Sediment source fingerprinting has been successfully deployed to provide information on the surface and subsurface sources of sediment in many catchments around the world. However, there is still scope to re-examine some of the major assumptions of the technique with reference to the number of fingerprint properties used in the model, the number of model iterations and the potential uncertainties of using more than one sediment core collected from the same floodplain sink. We investigated the role of subsurface erosion in the supply of fine sediment to two sediment cores collected from a floodplain in a small degraded catchment in the Eastern Cape, South Africa. The results showed that increasing the number of individual fingerprint properties in the composite signature did not improve the model goodness-of-fit. This is still a much debated issue in sediment source fingerprinting. To test the goodness-of-fit further, the number of model repeat iterations was increased from 5000 to 30,000. However, this did not reduce uncertainty ranges in modelled source proportions nor improve the model goodness-of-fit. The estimated sediment source contributions were not consistent with the available published data on erosion processes in the study catchment. The temporal pattern of sediment source contributions predicted for the two sediment cores was very different despite the cores being collected in close proximity from the same floodplain. This highlights some of the potential limitations associated with using floodplain cores to reconstruct catchment erosion processes and associated sediment source contributions. For the source tracing approach in general, the findings here suggest the need for further investigations into uncertainties related to the number of fingerprint properties included in un-mixing models. The findings support the current widespread use of ≤5000 model repeat iterations for estimating the key sources of sediment samples.

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ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Environmental Management - Volume 194, 1 June 2017, Pages 27-41
نویسندگان
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