The soil cover of urban areas drastically reduces infiltration rates and increases the risk of stormwater flooding. In this context, nature-based solutions (NBS) are well-acknowledged strategies for sustainable stormwater management and water cycle restoration. As NBS, urban trees provide significant benefits to hydrological balance through rainfall interception, evapotranspiration, and water storage in the underlying soil. This paper proposes an analytical-probabilistic model to evaluate the performance of urban trees for stormwater control. The study investigates the effects on the surface runoff of the main hydrological and environmental variables involved, in particular the infiltration rate into the soil, and the impermeable contributing areas. The reliability of the analytical-probabilistic approach to estimate the surface stormwater runoff (in terms of both runoff probability and average value) was validated through its application to a case study in the city of Lecco (Italy). The results confirmed that the beneficial impact of urban trees on stormwater control is greater during leaf-on season (late spring-summer at Lecco latitude) and when a proper infiltration rate into the soil beneath the tree is ensured.

中文翻译：

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城市树木作为基于自然的雨水径流控制解决方案的作用


城市地区的土壤覆盖大大降低了渗透率，并增加了雨水泛滥的风险。在此背景下，基于自然的解决方案 （NBS） 是公认的可持续雨水管理和水循环恢复策略。作为 NBS，城市树木通过降雨拦截、蒸散和底层土壤中的蓄水为水文平衡提供了显着的好处。本文提出了一个分析概率模型来评估城市树木的雨水控制性能。该研究调查了所涉及的主要水文和环境变量对地表径流的影响，特别是渗入土壤的速率和不透水贡献区域。通过将其应用于 Lecco 市（意大利）的案例研究，验证了分析概率方法估计地表雨水径流（就径流概率和平均值而言）的可靠性。结果证实，在绿叶季节（莱科纬度春末夏末）和确保适当的渗透率进入树下土壤时，城市树木对雨水控制的有益影响更大。