渤海莱州湾南岸平原浅埋古河道带及其与海(咸)水入侵关系研究

根据2100余个钻孔资料,并结合大比例尺地形图、航片、卫片判读分析,以及野外实地考察和沉积物样品的粒度分析、岩相分析、14C测年,研究了莱州湾南岸平原浅埋古河道带的分布规律、埋藏和沉积特征、古河道的分期断代以及与海(咸)水入侵关系。该区在埋深60m内的浅埋古河道带,可分成弥河、潍河和白浪河3个系统,它们大都呈掌状、放射状分布,并与其所属河流的冲洪积扇范围相吻合。该区古河道的形成和发育与古气候和海平面变化密切相关。自晚更新世晚期以来,该区有4期古河道发育,其中玉木旱冰期古河道和玉术主冰期古河道的砂层沉积粒度粗、连通性好、分布广,既是富水性强、水质好的淡水含水层,又是该区海(咸)水入侵的主要通道。控制在浅埋古河道带超采地下淡水,并在丰水季节利用其进行地下水回灌,是治理该区海(咸)水入侵灾害的重要措施之一。

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 2100 drilling hole data, the lithofacies analysis, 14 C dating of the sediments, and t he field investigation, etc. the distribution regularities, buried situation and sedimentary characteristics of the shallow buried paleochannel zoneson the south coast pain of Laizhou Bay, and their stage division and their relations with sea(salt)-water intrusion have been studied.The shallow buried paleochannel zones within a buried depth of 60 m on the plain can be divided into the Mihe River, the WeiheRiver and the Bailang River system. The shallow buried paleochannel zones appear in palm-like and radial distribution, and coinciderespectively with their river's alluvial diluvial fans. On the plain within a buried depth of 60 m, there are 4 stages of paleochannelswhich have developed since the late period of Late Pleistocene, in which the paleochannel sand strata of the early Wurm glaciationand the principal Wurm glaciation, with coarse granularity, well continuity and wide distribution, are both rich in fresh groundwaterand the ban passage ways of sea (salt) -water intrusion. It is the inportant measures of managing salt-water intrusion to control excessive extraction of fresh groundwater in the shallow--buried paleochannel zones and to recharge the groundwater using the paleochannel sones in the rainy seasons.