• Title/Summary/Keyword: The Yellow River Valley

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On Phylogenetic Relationships Among Native Goat Populations Along the Middle and Lower Yellow River Valley

  • Chang, H.;Nozawa, K.;Liu, X.L.;Geng, S.M.;Ren, Z.J.;Qin, G.Q.;Li, X.G.;Sun, J.M.;Zheng, H.L.;Song, J.Z.;Kurosawa, Y.;Sano, A.;Jia, Q.;Chen, G.H.
    • Asian-Australasian Journal of Animal Sciences
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    • v.13 no.2
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    • pp.137-148
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    • 2000
  • This paper is based on the 9 goat colonies along the middle and lower Yellow River valley and 7 local goat colonies in the Northeast, Tibet and the Yangtze valley. After collecting the same data about the 22 goat colonies in China and other countries, it establishes and composes the matrix of fuzzy similarity relation describing the genetic similarities of different colonies. It also clusters 38 colonies according to their phylogenetic relationship. The establishment of the matrix and the cluster are effected in terms of the frequency of 18 loci and 43 allelomorphs in blood enzyme and other protein variations. The study proves that the middle Yellow River valley is one of the taming and disseminating centers of domestic goats in the South and East of Central Asia. Compared with other goat populations in this vast area, the native goat populations in the west of Mongolian Plateau, the Qinghai-Tibet Plateau and the middle Yellow River valley share the same origin. The colonies in the lower Yellow River valley and those in the middle valley, however, are relatively remote in their phylogenetic relationship. The native goat colonies in the southeast of Central Asia can be classified into two genetic groups: "East Asia" and "South Asia" and the colonies in Southeast Asia belong to either group.

The relationships of erosion and river channel change in the Geum river basin (금강유역의 침식과 하상변동과의 관계)

  • 양동윤;짐주용;이진영;이창범;정혜정
    • The Journal of Engineering Geology
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    • v.10 no.2
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    • pp.52-74
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    • 2000
  • The basement rock of upper stream of Keum River Valley consists of Precambrian gneiss which is resistant to weathering. That of mid and lower stream valley, however, is mainly composed of Mesozoic granites which are vulnerable to weathering. The upstream part of Geum River Basin is typified by the deeply-incised and steep meandering streams, whereas mid and lower part is characterized by wide floodplain and gently dipping river bottom toward the Yellow Sea. In particular flooding deposits, in which are imprinted a number of repetitions of erosion and sedimentation during the Holocene, are widely distributed in the lower stream of Geum River Basin. For understanding of erosions in the mid and lower stream of Geum River Basin, the rate of erosion of each small basins were estimated by using the data of field survey, erosional experiments and GIS ananlysis. It was revealed that erosion rate appeared highest in granite areas, and overall areas, in this field survey were represented by relatively high erosion rates. By implemeatation of remote sensing and imagery data, the temporal changes of river bed sediments for about last 11 years were successfully monitored. Observed as an important phenomenon is that the river bed has been risen since 1994 when an embankment (Dyke) was constructed in the estuarine river mouth. From the results derived from the detailed river bed topographical map made in this investigation, the sedimentation of the lower river basin is considered to be deposited with about 5 cm/year for the last 11 years. Based on this river bed profile analysis by HEC-6 module, it is predicted that Geum River bed of Ganggyeong area is continuously rising up in general until 2004. Although extraction of a large amount of aggregates from Gongju to Ganggyung areas, the Ganggyung lower stream shows the distinct sedimentation. Therefore, it is interpreted that the active erosions of tributary basins Geum drainage basins can affect general river bed rising changes of Geum River.

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