Table_1_Research trends of nature-based solutions: from urban to climate change.DOCX

As one of the efforts to combat climate change and the biodiversity crisis, an interest in nature-based solutions (NbS) has been growing. Although there have been diverse discussions on NbS, it is still insufficient to find a quantitative evaluation of the global research trends in which field and to what extent NbS has been studied. In this regard, this study employed latent Dirichlet allocation (LDA) topic modeling and keyword analysis to quantitatively evaluate the research trends of NbS. Among research papers on NbS searched on SCOPUS, 2,625 studies (2009–2022) were analyzed by LDA. As a result, NbS-related articles were classified into seven topics (i.e., Urban governance, Urban green infrastructure, Wastewater treatment, Coastal protection, Flood mitigation, Carbon sequestration, and Sustainable agriculture). Of these, the urban and water-related topics accounted for the largest proportion. In contrast, the carbon sequestration and sustainable agriculture topics accounted for a smaller proportion, but the proportion significantly increased over time. As a result of keyword analysis, the frequency of urban and water keywords remained high. In contrast, the frequency of climate change and carbon keywords was low and has recently increased. In the keyword network, the co-occurrence frequency and connection of urban and water keywords were initially high. Still, over time, keywords related to climate change and carbon increased similarly to those related to urban and water. The findings of this study imply that NbS has mainly focused on urban and water-related researches. Still, climate change and carbon-related researches may also be actively handled in relation to NbS in the near future.

为应对气候变化与生物多样性危机，基于自然的解决方案（NbS）的研究兴趣日益增长。尽管关于NbS的讨论纷纭，但对于该领域全球研究趋势的量化评估及其研究程度，尚显不足。鉴于此，本研究采纳了潜在狄利克雷分配（LDA）主题建模与关键词分析，对NbS的研究趋势进行量化评估。在SCOPUS数据库中检索到的NbS相关研究论文中，共有2,625篇（2009-2022年）研究被LDA分析。据此，NbS相关文章被划分为七个主题（即：城市治理、城市绿色基础设施、污水处理、海岸保护、洪水缓解、碳封存和可持续农业）。其中，城市与水资源相关主题占据了最大比例。相比之下，碳封存与可持续农业主题所占比例较小，但随时间推移，其比例显著上升。关键词分析结果显示，城市与水资源相关关键词的频率保持较高。而气候变化与碳相关关键词的频率则较低，但近期有所上升。在关键词网络中，城市与水资源相关关键词的共现频率和连接度最初较高，但随着时间的推移，与气候变化和碳相关关键词的频率与城市和水资源相关关键词的增长趋势相似。本研究发现表明，NbS研究主要集中于城市与水资源相关领域，但未来与气候变化和碳相关的NbS研究也可能得到积极推动。