Mainstreaming Rain Gardens into Chiang Rai's Sustainable Development Agenda: A Desk-Based Policy Framework

Urban flooding and wetland degradation remain persistent challenges for secondary cities in Northern Thailand, including Chiang Rai. Conventional drainage and flood-control measures are limited in their ability to manage high-intensity rainfall while also supporting biodiversity and community well-being. This paper develops a desk-based policy framework to mainstream rain gardens as a nature-based solution (NbS) within Chiang Rai's sustainable development goals. Drawing on international literature on Japanese rain garden design and global low-impact development (LID) practices, the study adapts technical principles such as infiltration media layers, micro-topographic water retention, and plant zoning for potential use in tropical northern Thailand. Secondary data, including urban planning documents, national climate adaptation strategies, and open-source geospatial datasets, are synthesized to identify opportunities for integrating local governance. The framework proposes three pathways: (i) regulatory measures, like adding rain garden credits into urban building codes and stormwater management guidelines

城市内涝与湿地退化仍是泰国北部次级城市持续面临的共性挑战，清莱（Chiang Rai）亦在此列。传统排水与防洪措施在应对强降雨时能力有限，且无法兼顾生物多样性保护与社区福祉提升。本研究构建了一套基于案头研究的政策框架，旨在将雨水花园作为基于自然的解决方案（nature-based solution, NbS）融入清莱可持续发展目标的主流化进程。研究借鉴日本雨水花园设计的国际研究成果与全球低影响开发（low-impact development, LID）实践经验，适配了入渗介质层、微地形蓄水、植物分区等技术原理，以适配泰国北部热带地区的应用场景。本研究整合了城市规划文件、国家气候适应战略及开源地理空间数据集等二手数据，以识别融入地方治理的可行路径。该框架提出三大实施路径：其一为规制举措，例如在城市建筑规范与雨水管理导则中增设雨水花园相关抵免积分项