莱州湾海庙后潮间带海水地下水相互交换研究
发布时间：2018-12-17 06:37
【摘要】：研究滨海地区海岸带含水层中的海水地下水相互交换作用,包括海底地下水排泄、地下水动态和溶质运移等,对评价滨海地区的地下水资源、正确区分近岸海域营养物质的来源以及改善海产养殖模式,具有重要的理论和实践意义。以往的海岸带海水地下水相互交换研究主要集中于沙质、砾石海滩,而对于在国内外滨海地区都广泛分布的泥质潮滩的研究却比较少。本文选取了莱州湾东岸某一典型泥质潮滩剖面作为实验场地,对该场地以前野外观测所用的单井进行改进,采用布设“对井”观测井的方法,估算了在考虑渗出面以及密度影响下海水地下水的交换量。本文研究的潮滩剖面长约450m,坡度1.8‰,沿垂直海岸方向均匀布设6口对井来观测地下水动态,从内陆向海向分别编号为W1、W2、W3、W4、W5、W6,每口对井在不同深度上安装两个LTC-Diver,每小时记录一次水压、温度及电导率,监测时间为2013年8月22日00:00到2013年9月21日00:00,共计720小时。同时还利用原位多径降水头法测量了每口井处沉积物的垂向渗透系数,渗透系数变化范围从4.06×10-6 ms-1到7.30×10-5 ms-1,其中W4渗透系数最大,W1渗透系数最小。每口观测井中上下Diver的平均盐度变化范围从14.2gL-1到24.5gL-1,其中W1下部Diver平均盐度最低,W5下部Diver平均盐度最高。由于W2井安装后土壤扰动较大,低潮时,井中水位低于上部Diver所在的位置高程,上部Diver位置由饱水带变为包气带。此时所测压力为负压,但仍可作为地下水的水压。利用广义达西定律,对所有观测井中的地下水流速进行计算,估算出整个剖面长度上海底地下水的排泄量(SGD)和入渗量分别是11.1 m2 d-1和21.0 m2 d-1。观测井W4和W6之间的入渗量占整个剖面入渗量的42.6%,排泄量(SGD)占总排泄量的43.9%。本研究中的地下水排泄量是前人在本场地研究所得SGD的1.3倍,入渗量是其入渗量的1.4倍。
[Abstract]:To study the interaction of seawater and groundwater in coastal aquifer in coastal area, including the discharge of seabed groundwater, groundwater dynamics and solute transport, etc., and to evaluate the groundwater resources in coastal area. It is of great theoretical and practical significance to correctly distinguish the sources of nutrients and improve the aquiculture model of marine products. In the past, the study of sea water and groundwater exchange in coastal zone was mainly focused on sandy and gravel beaches, but there was little research on muddy tidal flat which was widely distributed in coastal areas both at home and abroad. In this paper, a typical muddy tidal flat section on the east coast of Laizhou Bay is selected as the experimental site to improve the single well used in the field observation before, and the method of setting up the "opposite well" observation well is adopted. The groundwater exchange capacity of seawater was estimated under the influence of seepage surface and density. The tidal beach profile studied in this paper is about 450 m long, with a slope of 1.8 鈥，
本文编号：2383820
[Abstract]:To study the interaction of seawater and groundwater in coastal aquifer in coastal area, including the discharge of seabed groundwater, groundwater dynamics and solute transport, etc., and to evaluate the groundwater resources in coastal area. It is of great theoretical and practical significance to correctly distinguish the sources of nutrients and improve the aquiculture model of marine products. In the past, the study of sea water and groundwater exchange in coastal zone was mainly focused on sandy and gravel beaches, but there was little research on muddy tidal flat which was widely distributed in coastal areas both at home and abroad. In this paper, a typical muddy tidal flat section on the east coast of Laizhou Bay is selected as the experimental site to improve the single well used in the field observation before, and the method of setting up the "opposite well" observation well is adopted. The groundwater exchange capacity of seawater was estimated under the influence of seepage surface and density. The tidal beach profile studied in this paper is about 450 m long, with a slope of 1.8 鈥，
本文编号：2383820
本文链接：https://www.wllwen.com/kejilunwen/haiyang/2383820.html
