Department of Civil Engineering, National Taipei University of Technology, Taipei, Taiwan.
Department of Civil Engineering, National Taipei University of Technology, Taipei, Taiwan.
Sci Total Environ. 2024 Oct 15;947:174545. doi: 10.1016/j.scitotenv.2024.174545. Epub 2024 Jul 6.
Rain gardens are widely used for low impact development (LID) or as a nature-based solution (NbS). They help to reduce runoff, mitigate hot temperatures, create habitats for plants and insects, and beautify landscapes. Rain gardens are increasingly being established in urban areas. In Taiwan, the Ministry of Environment (MoE) initiated a rain garden project in Taipei city in 2018, and 15 rain gardens have since been constructed in different cities. These Taiwanese-style rain gardens contain an underground storage tank to collect the filtrated rainwater, which can be used for irrigation. Moreover, the 15 rain gardens are equipped with sensors to monitor temperature, rainfall, and underground water levels. The monitoring data were transmitted with Internet of Things (IoT) technology, enabling the capture and export of real-time values. The water retention, temperature mitigation, water quality, and ecological indices of the rain gardens were quantified using field data. The results from the young rain gardens (1-3 years) showed that nearly 100 % of the rainfall was retained onsite and did not flow out from the rain gardens; however, if the stored water was not used and the tanks were full, the rainwater from subsequent storms could not be stored, and the tanks overflowed. The surface temperatures of the rain garden and nearby impermeable pavement differed by an average of 2-4 °C. This difference exceeded 20 °C in summer at noon. The water in the underground storage tanks had very low levels of SS and BOD, with averages of 1.6 mg/L and 5.6 mg/L, respectively. However, the E. coli concentrations were high, and the average was 6283 CFU/100 mL; therefore, washing or drinking water is not recommended. The ecological indices, i.e., the Shannon and Simpson indices, demonstrated the good flora status of the rain gardens after one year. Although the weather differed by city, the performance of the rain gardens in terms of water retention, temperature mitigation, rainwater harvesting, and providing biological habitats was consistent. However, maintenance influences rain garden performance. If the stored water is not frequently used, the stored volume is reduced, and the stored water quality degrades.
雨水花园被广泛用于低影响开发（LID）或自然为本的解决方案（NbS）。它们有助于减少径流、缓解高温、为植物和昆虫创造栖息地，并美化景观。雨水花园在城市地区越来越多地建立起来。在台湾，环境部（MoE）于 2018 年在台北市启动了一个雨水花园项目，此后在不同城市已建造了 15 个雨水花园。这些台湾风格的雨水花园包含一个地下储水箱来收集过滤后的雨水，可用于灌溉。此外，这 15 个雨水花园还配备了传感器来监测温度、降雨量和地下水位。监测数据通过物联网（IoT）技术传输，能够捕获和导出实时值。使用现场数据量化了雨水花园的持水、温度缓解、水质和生态指数。来自年轻雨水花园（1-3 年）的结果表明，近 100%的降雨量被保留在现场，没有从雨水花园中流出；但是，如果存储的水没有被使用，并且水箱已满，随后风暴的雨水就无法被储存，水箱会溢出。雨水花园和附近不透水路面的表面温度平均相差 2-4°C。在中午的夏季，这个差值超过 20°C。地下储水箱中的水的 SS 和 BOD 水平非常低，平均值分别为 1.6mg/L 和 5.6mg/L。然而，大肠杆菌浓度很高，平均值为 6283 CFU/100mL；因此，不建议用于清洗或饮用。生态指数，即香农和辛普森指数，在一年后表明雨水花园的良好植物状况。尽管城市之间的天气不同，但雨水花园在持水、温度缓解、雨水收集和提供生物栖息地方面的性能是一致的。然而，维护会影响雨水花园的性能。如果存储的水不经常使用，存储量会减少，存储水的质量也会下降。
