沿海地區地下水理論解析之研究

Abstract

近年來隨著沿海都市的快速發展及人口急速增加，用水量與日俱增。人類活動、農業灌溉水和水產養殖皆須仰賴大量的抽水。地下水位的變化導致沿海地區種種問題，例如：地層下陷、地下水鹽化和海水入侵。因此，沿海地下水解析解於1950年開始，國內外專家針對沿海地區受海潮波動影響地下水位之關聯性探討進行一系列研究。 為了精進解析解的真實性，本研究發展二維任意傾斜含水層解析解之通解，用以描述河口地區自由含水層和拘限含水層系統中水位受海潮波動的變化，同時考量人為因素導致之水文地質條件改變及含水層系統水文地質參數非等向性，使模式更趨於實際情形。研究已完成其可行性，並以此模式探討河口地區於不同水文地質情況和土壤特性，沿海滲漏含水層系統之地下水位動態變化。

In recent years the urban and industrial developments near the coastal area are rapid and therefore the associated population grows dramatically. More and more water demand for human activities, agriculture irrigation, and aquaculture relies on heavy pumping in coastal area. The decline of groundwater table may result in the problems of seawater intrusion and/or land subsidence. This study aims at developing a general analytical solution describing the head fluctuations in a 2D estuarine inclined aquifer system consisted of an unconfined aquifer, a confined aquifer, and an aquitard between them. Both the confined and unconfined aquifers are considered to be anisotropic. The solutions mentioned above will be shown to be special cases of the present solution. Some hypothetical cases regarding the head fluctuation in costal aquifers will be made to investigate the dynamic effects of water table fluctuation, hydrogeological conditions, and characteristics of soil on the groundwater level fluctuations in the 2D estuarine leaky aquifer system.