A study of the shallow-buried paleochannel zones and their relationswith sea(salt)-water intrusion on the south coast plain of Laizhou Bay

According to more than 2 100 drilling hole data, the lithofacies analysis, ¹⁴C dating of the sediments, and the field investigation, etc. the distribution regularities, buried situation and sedimentary characteristics of the shaVow buried paleochannel zones on the south coast plain of Laizhou Bay,and their stage division and their relations with sea(salt)-water intrusion have been studied. The shaVow buried paleochannel zones within a buried depth of 60 m on the plain can be divided into the Mihe River, the Weihe River and the Bailang River system. The shallow buried paleochannel zones appear in palm-like and radial山stribution, and coincide respectively with their river's alluvial diluvial fans.On the plain within a buried depth of 60 m, there are 4 stages of paleochannels which have developed since the late period of Late Pleistocene, in which the paleochannel sand strata of the early Wüirm glaciation and the principal Wüirm glaciation,with coarse granularity, well continuity and wide distribution, are both rich in fresh groundwater and the main passage ways of sea (salt)-water intrusion. It is the inportant measures of managing salt-water intrusion to control cxcessive extraction of fresh groundwater in the shallow-buried paleochannel zones and to recharge the groundwater using the pale ochannel zones in the rainy seasons.