Urban microclimate varies for different urban morphologies in a city necessitating the assessment of impact of green roofs on the local microclimate in such typical morphologies. This paper explores the role of roof greening in regulating the local microclimate in Liège, Belgium, for nine realistic and unique urban morphological archetypes during a heatwave. The urban morphological archetypes are obtained based on a systematic data-driven approach using an extensive list of morphological parameters. Nine scenarios without green roofs and nine scenarios with green roofs are simulated using Solene-microclimat model. Green roofs are introduced only on the existing flat roofs identified using remote-sensing to analyse the realistic impact of roof greening. Our findings suggest that distinct morphologies in the archetypes result in distinctive impact of roof greening on these archetypes. For instance, green roofs can reduce surface temperature effectively in compact high-rise archetypes, whereas green roofs' potential to reduce air temperature is limited. While green roofs can effectively reduce surface and air temperature in compact low-rise archetypes, most compact low-rise archetypes are residential and have fewer flat roofs to green. However, large low-rise archetypes, which are predominantly industrial/commercial, can be retrofitted with green roofs, considering large potential of roof greening. This study provides insight into the interplay between urban morphology, realistic roof greening potential, and the UHI effect on local microclimate, improving our understanding of microclimate regulation with green roofs.

中文翻译：

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城市形态对绿化屋顶调节局部小气候潜力的影响——以比利时列日为例


城市小气候因城市形态的不同而变化，因此需要评估绿色屋顶对此类典型形态中当地小气候的影响。本文探讨了屋顶绿化在调节比利时列日当地小气候中的作用，探讨了热浪期间九种真实而独特的城市形态原型。城市形态原型是基于系统的数据驱动方法获得的，该方法使用广泛的形态参数列表。使用 Solene-microclimat 模型模拟了 9 个没有绿色屋顶的情景和 9 个有绿色屋顶的情景。绿色屋顶仅在使用遥感技术确定的现有平屋顶上引入，以分析屋顶绿化的实际影响。我们的研究结果表明，原型中的不同形态导致屋顶绿化对这些原型产生独特的影响。例如，绿色屋顶可以有效地降低紧凑型高层建筑的表面温度，而绿色屋顶降低空气温度的潜力是有限的。虽然绿色屋顶可以有效地降低紧凑型低层原型的表面和空气温度，但大多数紧凑型低层原型是住宅，并且需要绿色的平屋顶较少。然而，考虑到屋顶绿化的巨大潜力，主要是工业/商业的大型低层原型可以改造成绿色屋顶。这项研究深入了解了城市形态、现实屋顶绿化潜力以及 UHI 对当地小气候的影响之间的相互作用，从而提高了我们对绿色屋顶小气候调节的理解。