Water and Water Structures Engineering Department, Faculty of Engineering, Zagazig University, Zagazig, 44519, Egypt.
Division of Agricultural Engineering, ICAR-Indian Agricultural Research Institute, New Delhi 110012, India.
Sci Total Environ. 2022 Aug 25;836:155656. doi: 10.1016/j.scitotenv.2022.155656. Epub 2022 May 2.
Sustainable management of natural water resources and food security in the face of changing climate conditions is critical to the livelihood of coastal communities. Increasing inundation and saltwater intrusion (SWI) will likely adversely affect agricultural production and the associated beach access for tourism. This study uses an integrated surface-ground water model to introduce a new approach for retardation of SWI that consists of placing aquifer fill materials along the existing shoreline using Coastal Land Reclamation (CLR). The modeling results suggest that the artificial aquifer materials could be designed to decrease SWI by increasing the infiltration area of coastal precipitation, collecting runoffs from the catchment area, and applying treated wastewater or desalinated brackish water-using coastal wave energy to reduce water treatment costs. The SEAWAT model was applied to verify that it correctly addressed Henry's problem and then applied to the Biscayne aquifer, Florida, USA. In this study, to better inform Coastal Aquifer Management (CAM), we developed four modeling scenarios, namely, Physical Surface Barriers (PSB), including the artificial aquifer widths, permeability, and side slopes and recharge. In the base case scenario without artificial aquifer placement, results show that seawater levels would increase aquifer salinity and displace large amounts of presently available fresh groundwater. More specifically, for the Biscayne aquifer, approximately 0.50% of available fresh groundwater will be lost (that is, 41,192 m) per km of the width of the aquifer considering the increasing seawater level. Furthermore, the results suggest that placing the PSB aquifer with a smaller permeability of <100 m per day at a width of approximately 615 m increases the available fresh groundwater by approximately 45.20 and 43.90% per km of shoreline, respectively. Similarly, decreasing the slope on the aquifer-ocean side and increasing the aquifer recharge will increase freshwater availability by about 43.90 and 44.50% per km of the aquifer. Finally, placing an aquifer fill along the shallow shoreline increases net revenues to the coastal community through increased agricultural production and possibly tourism that offset fill placement and water treatment costs. This study is useful for integrated management of coastal zones by delaying aquifer salinity, protecting fresh groundwater bodies, increasing agricultural lands, supporting surface water supplies by harvesting rainfall and flash flooding, and desalinating saline water using wave energy. Also, the feasibility of freshwater storage and costs for CAM is achieved in this study.
面对不断变化的气候条件，可持续管理自然水资源和粮食安全对于沿海社区的生计至关重要。洪水和盐水入侵（SWI）的增加可能会对农业生产和相关的海滩旅游通道产生不利影响。本研究使用一个综合的地表水-地下水模型，提出了一种新的减缓 SWI 的方法，即在现有海岸线沿线放置含水层填充材料，采用沿海土地开垦（CLR）。建模结果表明，人工含水层材料可以通过增加沿海降水的渗透面积、收集集水区的径流以及利用沿海波浪能处理废水或淡化微咸水来减少水的处理成本，从而减少 SWI。SEAWAT 模型被应用来验证它是否正确地解决了 Henry 问题，然后被应用于美国佛罗里达州的比斯坎含水层。在本研究中，为了更好地为沿海含水层管理（CAM）提供信息，我们开发了四个建模情景，即物理地表屏障（PSB），包括人工含水层的宽度、渗透性和边坡以及补给。在没有人工含水层放置的基础案例中，结果表明，海水水位将增加含水层的盐度，并置换大量目前可用的淡水地下水。更具体地说，对于比斯坎含水层，考虑到海水水位的上升，每公里含水层的宽度将损失约 0.50%的可用淡水地下水（即 41192 立方米）。此外，研究结果表明，在宽度约为 615 米的地方，放置渗透性<100 米/天的 PSB 含水层，分别可使海岸线每公里的可用淡水地下水增加约 45.20%和 43.90%。同样，降低含水层-海洋一侧的边坡并增加含水层补给，将使每公里含水层的淡水供应增加约 43.90%和 44.50%。最后，在浅岸沿线放置含水层填充材料可以通过增加农业生产和可能的旅游来增加沿海社区的净收入，从而抵消填充材料的放置和水的处理成本。本研究通过延迟含水层盐度、保护淡水体、增加农业用地、通过收集降雨和暴洪来支持地表水供应以及利用波浪能淡化咸水，对沿海地区的综合管理具有重要意义。此外，本研究还实现了 CAM 中淡水储存的可行性和成本。
