基于水化学的东海岛海水入侵时空变化特征

摘要

海水入侵对海岛海岸带地区地下淡水以及生态景观的变化存在重要影响,是该区域重要的灾害地质问题之一.海水入侵区域由于受到不同时段、地段地下淡水补给等可变因素影响,具有时空变化的特性.以东海岛东南部为主要研究靶区,利用三线图法对该区域2012年12月~2014年8月周期性监测数据进行研究分析,并以HCO3-和Cl-为划分依据,构建海水入侵程度的划分标准,对不同时期的海水入侵情况做了研究.分析表明,监测期内东海岛经历了多次海水入侵-后退过程,入侵量分别为56.7%、51.1%、56.4%、42.7%、36.5%、76.9%、66.8%和75.8%,年际对比表明,东海岛海水入侵有日趋加重趋势.%Seawater intrusion exists a significant impact on variation of the groundwater and ecological landscape in the islands and coastal zone, which is one of the important geological disasters of the regions. Due to the influence of the fresh groundwater supply and other variable factors in the different time intervals and spaces, seawater intrusion areas have the characteristics of temporal and spatial variation. Taking the southeast of the Donghai Island as the main research target, this paper used the method of piper diagram to analyze the measured data from December 2012 to August 2014, divided the grade of seawater intrusion according to the content of HCO 3-and Cl-, and studied the seawater intrusion in different pe-riods. The analysis show that the Donghai Island underwent many processes of seawater intrusion, of which the percentages are 56.7%, 51.1%, 56.4%, 42.7%, 36.5%, 76.9%, 66.8%and 75.8%respectively.