Many coastal and island communities depend on groundwater as the only source of freshwater, making it an invaluable resource. In the Mediterranean region, groundwater resources are highly vulnerable to natural and anthropogenic pressures, such as overexploitation, climate change, seasonal variations in precipitation, and seawater intrusion. Hence, an understanding of hydrogeological processes and groundwater chemistry is a basis for the sustainable management of coastal and island groundwater resources. Vis, a small and remote karst island in the Adriatic Sea, exhibits peculiar geological and hydrogeological settings, resulting in the island’s autonomous water supply. The current pumping capacity (maximum of 42 l/s) meets most of the demand, but intensive summer tourism and climate change exert high stress on groundwater resources during the dry season. Consequently, in the last decade, occasional reductions for consumers occurred. Monitoring of in situ physicochemical parameters and groundwater sampling for chemical and isotopic analyses were conducted from 2020 to 2023 at deep borewells, shallow dug wells, and springs. Hydrochemical interpretation indicated that groundwater chemistry was affected primarily by carbonate and sulfate rock dissolution, mixing with seawater, reverse ion exchange, and dedolomitization. The majority of groundwater samples exhibit Ca–HCO₃ hydrochemical facies, followed by Na–Cl and mixed facies. The low percentage of seawater in the mixture indicated that seawater intrusion is not too extensive even during prolonged dry periods, implying a favorable hydrostatic regime with relatively small but sufficient groundwater reserves of the island’s aquifers, although the investigated period was characterized by significantly lower precipitation with respect to the 30-year average.

许多沿海和岛屿社区依赖地下水作为唯一的淡水来源，使其成为宝贵的资源。在地中海地区，地下水资源极易受到自然和人为压力的影响，例如过度开采、气候变化、降水季节变化和海水入侵。因此，了解水文地质过程和地下水化学是沿海和岛屿地下水资源可持续管理的基础。维斯岛是亚得里亚海中一座偏远的喀斯特小岛，具有奇特的地质和水文地质环境，导致岛上可以自主供水。目前的抽水能力（最大42升/秒）可以满足大部分需求，但密集的夏季旅游和气候变化对旱季的地下水资源造成了很大压力。因此，在过去十年中，消费者的价格偶尔会出现下降。 2020年至2023年，对深井、浅井和泉水进行了原位物理化学参数监测以及地下水采样以进行化学和同位素分析。水化学解释表明地下水化学主要受到碳酸盐和硫酸盐岩石溶解、与海水混合、反向离子交换和去白云石化的影响。大部分地下水样品呈现Ca–HCO ₃水化学相，其次是Na–Cl 和混合相。 混合物中海水的比例较低，表明即使在长期干旱期间，海水入侵也不会太广泛，这意味着岛上含水层的地下水储量相对较小但充足，但存在有利的静水力状况，尽管调查期间的特点是降水量显着减少，相对于 30 年平均水平。