The temperature distribution in coastal aquifers is determined by the effect of different heat sources: surface water recharge, sea infiltration, and geothermal heat. In previous studies, the signal generated in groundwater by each source was individually studied, and in the case of geothermal heat, it was often not considered. This research is the first in considering all possible sources of heat in a coastal aquifer simultaneously by using a combination of field data and numerical modeling to present a reference model based on the characteristics of a real aquifer. The position of the freshwater-saltwater interface (FSI) and its effect on temperature distribution have been modeled considering variable-density flow, coupled heat and solute transport. This study broadens the theoretical knowledge of temperature distribution in coastal aquifers based on a sensitivity analysis of hydraulic and thermic parameters. Furthermore, a case study (the Motril-Salobreña aquifer) was modeled with field data calibration to test the applicability to real aquifers. The new insights gained through this study provide integrated knowledge of the temperature distribution in coastal areas and establish the basis for future research using heat as a tracer in seaside aquifers.

沿海含水层的温度分布取决于不同热源的影响：地表水补给、海水入渗和地热。在以前的研究中，每个来源在地下水中产生的信号是单独研究的，而在地热的情况下，往往没有考虑。该研究首次通过结合使用现场数据和数值建模来同时考虑沿海含水层中所有可能的热源，以提供基于实际含水层特征的参考模型。淡水-咸水界面 (FSI) 的位置及其对温度分布的影响已在考虑变密度流、耦合热和溶质传输的情况下进行建模。本研究基于对水力和热参数的敏感性分析，拓宽了沿海含水层温度分布的理论知识。此外，案例研究（Motril-Salobreña 含水层）通过现场数据校准进行建模，以测试对实际含水层的适用性。通过这项研究获得的新见解提供了沿海地区温度分布的综合知识，并为未来使用热量作为海滨含水层示踪剂的研究奠定了基础。