In deltaic areas, riverine and coastal waters interact; hence, these highly dynamic environments are particularly sensitive to climate change. This adds to existing anthropogenic pressures from irrigated agriculture, industrial infrastructure, urbanization, and touristic activities. The paper investigates the estimated future variations in the dynamics of surface and coastal water resources at a Mediterranean deltaic environment for the twenty-first century. Therefore, an Integrated Deltaic Risk Index (IDRI) is proposed as a vulnerability assessment tool to identify climate change impact (CCI) on the study area. For this purpose, three regional climate models (RCM) are used with representative concentration pathways (RCPs) 4.5 and 8.5 for short-term (2021–2050) and long-term (2071–2100) future periods. Extensive numerical modeling of river hydrology, storm surges, coastal inundation, water scarcity, and heat stress on irrigated agriculture is combined with available atmospheric data to estimate CCI on the Nestos river delta (Greece). The IDRI integrates modeling results about (i) freshwater availability covering agricultural demands for three water consumption scenarios, i.e., a reference (REF), a climate change (CC), and an extended irrigation (EXT) scenario, combining river discharges and hydropower dam operation; (ii) inundated coastal areas due to storm surges; and (iii) heat stress on cultivated crops. Sustainable practices on irrigated agriculture and established river basin management plans are also considered for the water demands under combinatory scenarios. The differentiations of model outputs driven by various RCM/RCP combinations are investigated. Increased deltaic vulnerability is found under the RCP8.5 scenario especially for the long-term future period. The projected IDRI demonstrates the need for integrated water resources management when compared with risk indexing of individual water processes in the study area.

在三角洲地区，河流和沿海水域相互作用；因此，这些高度动态的环境对气候变化特别敏感。这增加了灌溉农业，工业基础设施，城市化和旅游活动带来的现有人为压力。本文研究了二十一世纪地中海三角洲环境中地表和沿海水资源动态的估计未来变化。因此，提出了综合三角洲风险指数（IDRI）作为脆弱性评估工具，以识别对研究区域的气候变化影响（CCI）。为此，在短期（2021-2050年）和长期（2071-2100年）未来期间，使用三个具有代表性的集中路径（RCP）4.5和8.5的区域气候模型（RCM）。结合河流水文，风暴潮，沿海淹没，缺水和灌溉农业的热应力的广泛数值模型，结合可用的大气数据，估算内斯托斯河三角洲（希腊）的CCI。IDRI集成了有关以下方面的建模结果：（i）结合了河流排放和水电大坝的三种水消耗情景，即参考水（REF），气候变化（CC）和扩展灌溉（EXT）情景的农业需求操作 （ii）由于风暴潮而淹没的沿海地区；（iii）耕作作物的热胁迫。在综合方案下，还考虑了灌溉农业的可持续做法和已制定的流域管理计划。研究了由各种RCM / RCP组合驱动的模型输出的差异。在RCP8.5方案下，尤其是在长期的将来，发现三角洲的脆弱性增加。与研究区域中单个水资源过程的风险指数相比，预计的IDRI证明了对水资源综合管理的需求。