关键词: 复合指纹, 小流域, 泥沙源地

Abstract:

The application of the technique of composite fingerprinting to the identification of sediment sources is based on the assumption that the type of potential sediment sources could be confirmed and the sum of the contributions of the sediment sources equals to 1. However, the uncertainty in prediction of potential sediment sources would have some impact on accuracy of the results. The upstream of the Jiuxiang River in Nanjing was investigated for case study. Mean significance tests were carried out of fingerprint factors of the sediment sources in order to test whether each predicted source could be used individually as a potential sediment source. Meanwhile, effects of different sediment sources on the accuracy of the determination based on composite fingerprinting were analyzed and compared, in an attempt to quantitatively analyze shortages in the process of sediment source prediction and explore for ways to mitigate the impact of sediment source selection on identification of sediment sources. Results show that the four predicted sediment sources were readjusted as farmland, woodland and road. The readjustment significantly enhanced  the differences in fingerprint factors between the sediment sources. The highest identification rate of 89.2% was obtained in discriminating sources by using optimum composite fingerprinting. In terms of relative contribution of sediment, the sediment sources displayed an order of farmland (39.9%~87.8%) > wood land (<0.1%~47.7%) > and road land (0~25.6%).

Key words: composite fingerprinting, small catchment, sediment source