Application And Significance Of RS Technology During Late Cenozoic Studies In Lujiang Of Nujiang Valley

Nujiang River rises in the south of Mt. Tanggula in the north of Tibet, and the elevation of upstream is higher than the altitude of downstream. Landscapes of Nujing River mainly are composed by of mountains and neks, flows out from neks, turns to south and enters expansive NS valley from Saige of Baoshan which was called Lujiang River by local. In this area, deposits from Late Cenozoic well developed; consequently, it is the best place for researching the forming and evolution of. Nujiang River Valley.In this paper we select the Late Cenozoic Deposit of Lu River area of Nu River valley as object, and employed ETM+ and SPOT5 remote sensing images, by processing of proofreading, enhancing and amalgamation etc, then synthesize image for studying. By remote sensing image interoperation to different deposit of Late Cenozoic in the basin and field work, the author establishes the Stratigraphic sequence of basin’s Late Cenozoic, and then correlate with Jinsha River in this area to probe into the issues of Nujiang River’s forming era, forming and evolution, to supply new reference for the study of Nujiang River Valley’s development.(1) By establishing deciphering symbol and survey to different deposit, author maps the distribution of the Late Cenozoic deposit. Summarizing the former research of this area, the author builds 8 map filling units, and establishes the stratigraphic sequence of basin from Late Cenozoic according to annual measure dating of river terrace, deposits connection and physiognomy , and then finish the Quaternary Geology map in this area.(2)By remote sensing images and field work, high lake deposit and underlying gravel were found, which has important sense for studying the forming and evolvement of this Nujiang River Valley. Basing on the physiognomy configuration of the lake deposits and gravels, connection of different deposits and contrasting with Lacustrine Strata of Xigeda Formation of Jinsha River in adjacent area, it can be firstly conjectured that ancient Nujiang River formed in early-middle time of Pliocene, earlier than Early Pleistocene– Mid Pleistocene, when pervious researchers conjectured.(3)By investigation to the stratiform landforms-planation surface and fluvial terrace in this area, author discussed the forming and history of Nujiang River, and draws the conclusion that the evolvement of Nujiang River experienced three phases: Planation, Incision, and Alternation of Depositing - Incision. At the duration of Alternation of depositing– Incision, it happened four times of river incision, relatively that is four times of crustal uplift, and then formed current valley physiognomy.