English  |  正體中文  |  简体中文  |  Items with full text/Total items : 69937/69937 (100%)
Visitors : 23064548      Online Users : 316
RC Version 7.0 © Powered By DSPACE, MIT. Enhanced by NTU Library IR team.
Scope Tips:
  • please add "double quotation mark" for query phrases to get precise results
  • please goto advance search for comprehansive author search
  • Adv. Search
    HomeLoginUploadHelpAboutAdminister Goto mobile version


    Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/27631


    Title: Combined application of dc and TEM to sea-water intrusion mapping
    Authors: Yang,CH;Tong,LT;Huang,CF
    Contributors: 應用地質研究所
    Keywords: ELECTROMAGNETIC SOUNDINGS;TRANSIENT
    Date: 1999
    Issue Date: 2010-06-29 18:42:16 (UTC+8)
    Publisher: 中央大學
    Abstract: A geoelectric survey using a de resistivity method and a transient electromagnetic induction (TEM) method was carried out from 1986 to 1988. It was used to help map the lateral and vertical distributions of the freshwater/salt-water interface in the Pei-kang area on the west coast of Taiwan. The de and TEM soundings were performed at 79 localities over an area of 240 km(2) of Quaternary alluvium. Significant changes in pore-water conductivity at some places were detected by these two methods. A low resistivity value (<1.5 ohm-m) implies salt-water contamination of groundwater. The results of spatial distribution of apparent resistivity indicate the salt-water-affected aquifers are confined to the southwest part of the study area, and the affected aquifers are confined to the top of two aquifers. A geoelectric model with three to four layers is inferred from the joint inversion of de and TEM data. Based on a modified Archie's law suggested by the authors, an empirical relation between pore-water resistivity of the stratum and formation resistivity can be obtained. It can be used to convert the computed resistivity of each geoelectric layer (aquifer) to the resistivity of the water contained in these layer, thus leading to the assessment of groundwater contamination. Repeated de resistivity measurements have been carried out at selected locations once every year from 1986 to 1988. These data were used to monitor the temporal variation and a possible spreading of the salt-water invasion. During 1995, a de survey was conducted in the same area to compare with the de sounding results obtained in 1988. The final results provide an evaluation of the efficiency of groundwater management in the study area.
    Relation: GEOPHYSICS
    Appears in Collections:[應用地質研究所] 期刊論文

    Files in This Item:

    File Description SizeFormat
    index.html0KbHTML663View/Open


    All items in NCUIR are protected by copyright, with all rights reserved.

    社群 sharing

    ::: Copyright National Central University. | 國立中央大學圖書館版權所有 | 收藏本站 | 設為首頁 | 最佳瀏覽畫面: 1024*768 | 建站日期:8-24-2009 :::
    DSpace Software Copyright © 2002-2004  MIT &  Hewlett-Packard  /   Enhanced by   NTU Library IR team Copyright ©   - Feedback  - 隱私權政策聲明