中国沿海地区海水入侵机理及防治措施研究

Mechanism of sea water intrusion in China's coastal areas and its prevention countermeasures

早在1964年,中国大连市就发生了过量开采地下水引发的海水入侵现象。目前有十几座沿海城市发生了不同程度的海水入侵。海水入侵不仅恶化了滨海地区的生态环境,而且阻碍了沿海地区的经济发展。中国沿海地区海水入侵面积经历了20世纪80年代的快速增长后,近些年来呈缓慢增长态势,甚至有些地区海水入侵面积不再增加。为了深入了解海水入侵的机制,从20世纪70年代后期开始,有关学者相继开展了一系列研究,如通过水-岩间阳离子交换实验来了解海水入侵的地球化学作用,建立三维有限元变密度的过渡带数值模型模拟与预报海水入侵过程及发展趋势。为了预防和治理海水入侵,除了控制地下水开采量及开采布局外,沿海地区还因地制宜采取了相应的防治措施,包括人工补给、地下防渗帷幕、节水灌溉以及远距离调水等工程措施。

As early as 1964, Dalian City in China suffered sea water intrusion due to excessive extraction of groundwater. At the present time, 10-plus coastal cities are experiencing sea water intrusion to varying degrees. Sea water intrusion has not only damaged the ecological environment of seaside areas, but also hampered the economic development of coastal regions. Since the 1980s when the size of China＇ s coastal areas subjected to sea water intrusion increased rapidly, sea water intrusion has been showing a slowly declining tendency, with certain areas no longer undergoing expansion of sea water intrusion. In order to obtain an in-depth understanding of the mechanisms of sea water intrusion, since the late 1970s, scholars in this field has conducted a series of research, such as water-rock cation exchange experiments, to identify the geochemical action of sea water intrusion, and built a transitional belt numerical model which is typical of three-dimensional finite elements variable density to simulate and forecast the process and development trends of sea water intrusion. In order to prevent and treat sea water intrusion, besides controlling the amount of groundwater extraction and extraction layout, coastal areas must adopt relevant preventive and treatment measures according to actual local circumstances including artificial recharge, underground impervious screen, water-saving irrigation, and long-distance water diversion.