Abstract：
Droughts are the most expensive climate disasters as they leave long-term and chronic impacts on the ecosystem, agriculture, and human society. The intensity, frequency, and duration of drought events have increased over the years and are expected to worsen in the future on a regional and planetary/global scale. Nature-based solutions (NBS) such as wetland and floodplain restorations, green infrastructures, rainwater harvesting, etc., are highlighted as effective solutions to cope with the future impacts of these events. While the role of NBS in coping with the impacts of other disasters, such as floods, has been extensively studied, there has been a lack of comprehensive review of NBS targeting drought. The following paper provides a unique critical state-of-the-art literature review of individual drought-related NBS around the world, in Europe, and particularly in Belgium, and assesses the critical differences between the NBS applied globally and in Flanders. An extensive literature review was conducted to systematically analyze NBS, listing the type, the location, the status of the implementation, and the possible recommendations proposed to optimize future NBS applications. Finally, a comparison is made between small- and large-scale applications of NBS. By analyzing all these aspects, especially the level of effectiveness and recommendations, insight was gained into the future potential of NBS and possible improvements. The research indicated a lack of scientific publications, especially in Belgium. Hence, grey literature was also included in the literature review. Only four papers included a quantitative assessment regarding the effectiveness of drought on a global level, all stating a positive impact on groundwater recharge. In contrast, at regional and country levels, the performance of NBS was not quantified. The number of large-scale implementations is low, where landscape- or watershed-scale holistic approaches to drought mitigation are still scarce. Some successfully implemented projects are only very local and have a long realization time, two aspects that limit achieving visible impact at a larger scale. Among the many NBS, wetlands are recognized as highly effective in coping with drought but are still degraded or lost despite their significant restoration potential. A common effectiveness evaluation framework shall be followed, which gives policymakers a clear view of the different NBS investment options. Furthermore, a more collaborative approach is recommended globally, including different stakeholder groups, with specific attention to the local communities. To conclude, future research should increase the evidence base and implementation of drought-mitigating NBS.
摘要：
干旱是最昂贵的气候灾害，因为它们会对生态系统造成长期和长期的影响，农业,和人类社会。强度，频率,多年来，干旱事件的持续时间有所增加，预计未来将在区域和全球范围内恶化。基于自然的解决方案（NBS），如湿地和洪泛区恢复，绿色基础设施,雨水收集,等。,被强调为应对这些事件未来影响的有效解决方案。虽然国家统计局在应对其他灾害影响方面的作用，比如洪水,已经被广泛研究，缺乏对针对干旱的NBS的全面审查。以下论文提供了关于世界各地与干旱有关的NBS的独特的最新文献综述，在欧洲,尤其是在比利时，并评估在全球和法兰德斯应用的国家统计局之间的关键差异。进行了广泛的文献综述，系统地分析了国家统计局，列出类型，位置,执行情况，以及优化未来国家统计局应用的可能建议。最后,对NBS的小规模和大规模应用进行了比较。通过分析所有这些方面，特别是有效性和建议的水平，深入了解国家统计局的未来潜力和可能的改进。研究表明缺乏科学出版物，尤其是在比利时。因此，灰色文献也包括在文献综述中。只有四篇论文对全球干旱的有效性进行了定量评估，所有这些都说明了对地下水补给的积极影响。相比之下,在区域和国家层面，NBS的表现没有量化。大规模实现的数量少,在那里，景观或流域规模的整体缓解干旱的方法仍然很少。一些成功实施的项目只是非常本地化，实现时间很长，限制在更大范围内实现可见影响的两个方面。在众多NBS中,湿地被认为在应对干旱方面非常有效，但尽管具有巨大的恢复潜力，但仍在退化或丢失。应遵循共同的有效性评估框架，这让政策制定者对不同的国家统计局投资选择有了清晰的认识。此外，在全球范围内建议采取更具协作性的方法，包括不同的利益相关者群体，特别关注当地社区。最后，未来的研究应增加干旱缓解NBS的证据基础和实施。
