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CONTRIBUTIONS OF TUNNEL EROSION TO SEDIMENT YIELD IN A SEMI-ARID BASIN IN THE LOESS PLATEAU OF CHINA
T.X. ZHU Q.G. CAI S.H.LUK Dr. Department of Geography University of Minnesota-Duluth Duluth MN USA. Tel: --. Fax: --. Email: tzhu@d.umn.edu Researcher Institute of Geography Chinese Academy of Sciences Beijing 《国际泥沙研究》2000,(4)
1 INTRODUCTIONSubsurface erosion has been increasingly recognized as a significant hillslope geomorphologic process(Carson and ~y, 1972; McCaig, 1983;, Harvey, 1982;Bryan and Harvey, 1985; Crouch andMcGarrity, 1986; Walsh and Howeds, 1988). However, most of the studies were conducted in hubedareas, especially in Britain (e.g. Gilman and Newson, 1980; Jones, 1981; Wilson and Small, 1984; Jones,1987; Jones et al, 1997). Jones and Crane (1984) found that soil piping contributes about … 相似文献
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PIRKKO UKKONEN LEMBI LÕUGAS ILGA ZAGORSKA LIGITA LUKEVICA ERVINS LUKEVICS LINAS DAUGNORA HÖGNE JUNGNER 《Boreas: An International Journal of Quaternary Research》2006,35(2):222-230
A total of 45 subfossil reindeer (Rangifer tarandus) antlers and bones - artefacts excluded - have been found over the years in the Baltic countries of Estonia, Latvia and Lithuania. The relatively high number of specimens suggests a stable residence of the species in the eastern Baltic region. For the first time, 12 of these finds were radiocarbon-dated. The ages of the samples range between 12 085 and 9970 14C yr BP (14 180-11 280 cal. yr BP), and cover the Lateglacial and early Holocene, a time period during which climatic conditions shifted from periglacial to temperate. The dates suggest a rapid colonization of the area during the deglaciation period and a local extinction around the Pleistocene-Holocene boundary. The results of the study do not support the theory that the recent wild reindeer populations of northern Europe had their origin in the Late Weichselian reindeer populations of the eastern Baltic region. 相似文献
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