| dc.description.abstract | The increase in global water consumption is mainly owing to urbanization, growing agricultural activities, population growth, economic development, and improving living standards. Forcing the water resource authority concerned to seek new water resources to catch up with the gap of growing demand. Groundwater recharged from coastal aquifers to the ocean is a potential alternative water resource have drawn more attention in recent years. In this study, we aim to quantify the groundwater flux in coastal areas and the interaction between coastal aquifers and seawater intrusion and tidal variations, can provide valuable insights for groundwater resource management. The laboratory experiments include thermal analyzer to measure parameters such as the thermal conductivity of soil materials under saturated conditions, which help identify field geological materials and groundwater flux. The field tests involve heat tracer test (single-well). High-resolution continuous measurements of vertical temperature distribution in the wells are performed. According to the results of the heat tracer tests, the high thermal response zones are located at depths of 17-19m, 32-34m, and 42-47m. The depth range of 17-19m corresponds to gravel-sand mixture in the drilling core. The depth range of 32-34m corresponds to interbedded gravelly sand in the drilling core. The depth range of 42-47m corresponds to sand-silt mixture interbeds, with the sandy portion exhibiting a fine sand texture. The low thermal response zones are observed at depths of 3-6m, 6-11m, and 19-26m. The groundwater flux analysis revealed a low-permeability zone at 6-8m depth, with a flux of around 2.4m/day. Interestingly, heating tests exhibited contrasting heat transfer behavior in this zone. At depths of 19-26m, a slow groundwater flux of about 0.05 m/day and poor permeability aligned with the observed heat transfer reactions. However, the results clearly demonstrate the influence of tides on coastal aquifers, indicating a significant tidal effect in the study area. The relationship between tidal variations and the characteristics of coastal aquifers can be further explored. | en_US |