Abstract Irrigation is essential for a large part of Mediterranean agricultural systems, but scarce resources may cause conflicts between agricultural and domestic uses. These conflicts might be exacerbated by climate change, which could bring a drier climate and thus increase irrigation water demands while lowering supplies. These issues were addressed when designing a climate change adaptation plan for water resources in the Algarve region (southern Portugal), which was co-created between hydrologists and local stakeholders and policy-makers, by using the Dynamic Adaptive Policy Pathways (DAPP) approach to synthetize and communicate the results from hydrological modelling of future scenarios. The evolution of water availability and irrigation demands for key water assets in Algarve (southern Portugal) were simulated until 2100 for climate scenarios RCP4.5 and RCP8.5, using a modified version of Thornthwaite-Mather. The results show an increase in water stress, mainly in the RCP8.5 scenario. The results and need for adaptation were discussed with local and regional decision-makers and other stakeholders, and a set of adaptation measures was agreed upon. The discussed adaptation measures were then modelled and integrated the design of tailor-made DAPP. Finally, decision-makers and stakeholders were presented with DAPP and selected the most suitable and political reliable adaptation pathway that tackles projected climate change impacts in water resources until the end of the 21 st century. Stakeholders showed a strong preference for incremental and distributed small-scale measures, including the promotion of water use efficiency and landscape water retention, to large-scale measures such as wastewater recycling or new dams. A decrease in irrigation water use for agriculture was not considered socially desirable. Desalination was considered too costly for irrigation in the short term but kept in reserve in case other measures fail to keep water supplies at an acceptable level.

中文翻译：

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将水文模型整合到区域水政策中：共同创造葡萄牙南部水资源的气候变化动态适应性政策途径

摘要 灌溉对地中海农业系统的很大一部分至关重要，但稀缺的资源可能会导致农业和家庭用途之间的冲突。气候变化可能会加剧这些冲突​​，气候变化可能导致气候干燥，从而增加灌溉用水需求，同时降低供应。在为阿尔加维地区（葡萄牙南部）的水资源设计气候变化适应计划时解决了这些问题，该计划由水文学家、当地利益相关者和政策制定者共同制定，通过使用动态适应政策途径 (DAPP) 方法综合和交流未来情景的水文建模结果。对于气候情景 RCP4.5 和 RCP8.5，使用 Thornthwaite-Mather 的修改版本，模拟了 2100 年之前阿尔加维（葡萄牙南部）关键水资源资产的可用水量和灌溉需求的演变。结果显示水资源压力增加，主要是在 RCP8.5 情景中。与地方和区域决策者及其他利益相关者讨论了适应的结果和需求，并商定了一套适应措施。然后将讨论的适应措施建模并集成到量身定制的 DAPP 的设计中。最后，决策者和利益相关者看到了 DAPP，并选择了最合适和政治上可靠的适应途径，以应对 21 世纪末之前预计的气候变化对水资源的影响。利益相关者对增量和分布式小规模措施（包括提高用水效率和景观保水）表现出强烈偏好，而不是废水回收或新建水坝等大规模措施。减少农业灌溉用水不被认为是社会所希望的。海水淡化在短期内被认为对于灌溉来说成本太高，但保留在备用，以防其他措施无法将供水保持在可接受的水平。