[1]LEI Shan,WEI Xingping.Quantitative Tracing of Sediment Sources in Small Watersheds in Southwestern Karst Depressions by Composite Fingerprinting[J].Research of Soil and Water Conservation,2021,28(01):44-49.
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Research of Soil and Water Conservation[ISSN 1005-3409/CN 61-1272/P] Volume:
28
Number of periods:
2021 01
Page number:
44-49
Column:
Public date:
2021-01-10
- Title:
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Quantitative Tracing of Sediment Sources in Small Watersheds in Southwestern Karst Depressions by Composite Fingerprinting
- Author(s):
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LEI Shan1, WEI Xingping
1,2
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(1.College of Geography and Tourism Science, Chongqing Normal University, Chongqing 401331, China; 2.Chongqing Key Laboratory of Surface Process and Environment Remote Sensing in the Three Gorges Reservoir Area, Chongqing 401331, China)
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- Keywords:
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karst depression small watershed; composite fingerprint method; sediment source
- CLC:
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P964
- DOI:
-
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- Abstract:
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The karst depression small watershed has the characteristics of typical watershed in karst area. As an independent erosive sediment-generating unit, the study of sediment source in small karst depression watershed plays an important role in identifying the source of sediment in the depression and studying soil erosion process. The typical depression of the Qingmuguan karst trough valley in Chongqing was selected as study area. The method of composite fingerprint tracing was used to determine the geochemical element fingerprint characteristics of the sediment source in the karst depression, and the sediment source and contribution proportion of the typical karst depression in Chongqing rock were determined. The results showed that the best fingerprint factor combinations were found from 38 factors; the cumulative discrimination rates of U, χhf, AP and Mn were 63.4%, 68.3%, 73.2% and 82.9%, respectively, indicating that the fingerprint method can be used for the study of sediment sources in small watersheds in karst depressions; at the same time, the multivariate mixed model was used to indentify the mean percentages of contribution of the three sediment sources were carbonate surface soil(50.2%), deep soil(11.6%), clastic surface soil(38.2%), and the multi-mix model goodness fit test value was 0.83, and the relative average error was 13.9%, which further indicated that the soil loss in the karst depression carbonate area was serious, and much higher than the clastic soil. This study can provide the basis for the study of the evolution of soil erosion characteristics in karst depressions.