To analysis suspended sediment sources in a typical collapsing hill watershed in the granitic region

a collapsing hill watershed in the Longmen town

Anxi County

was selected as the research object

85 soil samples from four kinds of sediment source (erosive woodland

tea plantations

cultivated land

and the erosive area of collapsing hill area) were collected

in the meantime

erosion suspended sediment in the sampler in the channel was also collected. 34 kinds of fingerprint factor of the samples were analyzed

the best combination of fingerprint factors was screened

and the migration regularities of the sediment derived from different source were figured out. The results showed that there were significant differences in the same fingerprint factors of suspended sediments derived from different sources. By using the Kruskal-Wallis test and multivariate discriminant

the combination of Ca

Li

Sn

K and Ba was screened as the best combination of fingerprint factor

of which the cumulative contribution rate was more than 90%. The relative contribution of suspended sediment was approximately 33% by tea plantations

27% by cultivated land

and 20% by erosive woodland and collapsing hills. The goodness-of-fit test value of this Hybrid model was 0.89. Further analysis showed that the influence of rainfall on collapsing erosion was the biggest. Suspended sediment yields of collapsing erosion and tea plantations per unit area were obviously higher than those of other sediment sources

indicating that the prevention and control measures should be focused on the collapsing erosion and tea plantations in this study area.