For atolls, fresh groundwater lens (FGL) represents a crucial resource. Land reclamation is a common way of expanding the FGL. However, few studies have examined the effects of land reclamation on the FGL on the time scale. In this study, we are the first to quantify the effect of land reclamation on the time scale of dynamic processes in FGL. It was found that reclamation length and thickness had a much greater effect on fresh groundwater volume and lens stabilization time than the hydraulic conductivity of filling materials. Specifically, the fresh groundwater volume increased 1.18 times, and the lens stabilization time increased 1.12 times for every 1.67-fold increase in reclamation length. Furthermore, enhancing reclamation thickness from 1 to 12 m notably extended the lens stabilization time from over 15 to 46 years. Meanwhile, the effect on fresh groundwater volume diminished with an increasing reclamation length and thickness. Thus, extensive reclamation on atolls may not yield the expected outcomes, leading to high reusability and time costs. This work provides insights into the effects of land reclamation on FGL and evaluates these effects in terms of time. This valuable insight can guide the use of land reclamation to obtain more freshwater resources in a shorter period.

中文翻译：

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填海造地影响下环礁岛上淡水地下水透镜体形成的时间尺度

对于环礁来说，淡水透镜体 (FGL) 是一种重要的资源。土地复垦是扩大FGL的常见方式。然而，很少有研究在时间尺度上考察土地复垦对 FGL 的影响。在这项研究中，我们首次量化了土地复垦对 FGL 动态过程时间尺度的影响。研究发现，围垦长度和厚度对地下水量和透镜体稳定时间的影响比填充材料的导水率大得多。具体而言，围垦长度每增加1.67倍，地下水量增加1.18倍，透镜稳定时间增加1.12倍。此外，将填海厚度从 1 增加到 12 m 显着地将透镜稳定时间从 15 年延长到 46 年。同时，随着围垦长度和厚度的增加，对地下水量的影响减弱。因此，对环礁进行广泛的填海造地可能不会产生预期的结果，从而导致较高的可重复使用性和时间成本。这项工作深入了解土地复垦对 FGL 的影响，并根据时间评估这些影响。这一宝贵的见解可以指导利用土地围垦在更短的时间内获得更多的淡水资源。