GroMoPo Metadata for Lakshadweep atoll model

The groundwater is the only source of availability of fresh water in tiny coral islands. In the past decades, there has been growing demand for fresh water to meet the need of domestic besides other purposes. The aquifer system on these islands is fragile besides being subjected to various stresses like high subsurface discharge, increased abstraction, improper disposal of waste water and tidal waves of ocean all of which subject the aquifer prone to sea water intrusion and thus reduction and deterioration the water quality. Therefore, understanding the aquifer's behavior and then work out a sustainable option for fresh water is essential. The paper concerns optimizing of pumping and artificial recharge paces to reduce the effects of various stresses over tiny and fragile lens-shaped coral island aquifer system. The density driven ground water flow was simulated using SEAWAT (MODFLOW and MT3D based computer program) model. Detailed hydrogeological investigations were carried out to determine the quantity of freshwater that could be pumped to avoid the seawater intrusion into the aquifer through modeling. Initial heads, physical parameters and boundary conditions of the study area have been defined in the model based on field data, geophysical measurements and interpretations and hydrogeological studies. The model was calibrated by obtaining a match of computed and observed values of the water table, as hydraulic head is much more sensitive to pumping rates than any other stress. A few sentences about: flow model were utilized to derive optimal pumping rate; the effect of artificial recharge through the model, has also proved that the salt-water intrusion could be stopped by raising the water level through temporarily storing the artificially recharged water post construction of subsurface dam near the coast. (C) 2011 Elsevier Ltd. All rights reserved.

地下水是小型珊瑚岛唯一可获取的淡水来源。近数十年来，除各类其他用途外，生活用水的淡水需求日益攀升。这些岛屿上的含水层（aquifer）系统本身十分脆弱，同时还承受着多种胁迫：高强度地下排泄、地下水开采量增加、废水不当处置以及海洋潮汐作用，这些因素均会使含水层易于发生海水入侵（seawater intrusion），进而导致淡水资源量减少与水质恶化。因此，明晰含水层的赋存规律，并制定可持续的淡水保障方案，至关重要。
本研究聚焦于优化抽水速率与人工补给策略，以缓解小型脆弱透镜状珊瑚岛含水层系统所承受的各类胁迫。研究采用SEAWAT（一款基于MODFLOW与MT3D开发的计算机程序）模型开展密度驱动地下水流模拟。研究开展了详细的水文地质调查，并通过数值模拟确定了可安全开采的淡水水量，以防止海水入侵含水层。
研究基于野外实测数据、地球物理测量与解译成果以及水文地质研究结果，确定了研究区的初始水头、物理参数与边界条件，并将其应用于模型构建。鉴于水力水头对抽水速率的敏感性远高于其他胁迫因子，研究通过匹配模型计算值与实测地下水位值完成了模型率定。
本研究利用水流模型推导得到了最优抽水速率；同时通过模型分析人工补给的作用效果，证实可通过在海岸附近修建地下坝并临时储存人工补给水量以抬升地下水位，从而有效阻止盐水入侵。
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