不同气候区绿色屋顶蒸散发模拟研究

蒸散发过程决定绿色屋顶雨水滞留能力的恢复，进而影响绿色屋顶径流调控功能。基于水量平衡原理和Penman-Monteith公式，利用北京市实验绿色屋顶气象和蒸散发连续监测数据，构建并验证绿色屋顶水文过程模型，模拟分析不同气候区城市绿色屋顶蒸散发变化规律。结果表明：(1)该模型能较准确模拟绿色屋顶蒸散发量，率定和检验期的Nash-Sutcliffe效率系数分别为0.6385和0.6014,决定系数(R²)分别为0.7191和0.6168;(2)基质厚度相同的情况下，从半干旱区(兰州)、半湿润区(北京)到湿润区(武汉和广州),绿色屋顶日平均实际蒸散发量呈增加趋势；(3)增加基质厚度可提升绿色屋顶最大雨水滞留能力，进而增加绿色屋顶实际蒸散发量，但基质厚度对绿色屋顶蒸散发量的影响存在阈值，在兰州、北京、武汉和广州，当基质厚度分别超过10 cm、17 cm、24 cm和25 cm时，绿色屋顶的日平均实际蒸散发量变化不再明显。此外，不同气候区城市绿色屋顶的日平均实际蒸散发量也存在阈值，广州绿色屋顶日平均实际蒸散发量的阈值依次高于武汉、北京和兰州。本研究有望为我国不同气候区绿色屋...

Simulation of evapotranspiration from green roofs in different climatic zones

Evapotranspiration restores stormwater retention capacity of green roofs during inter-event dry periods and thus affects their stormwater retention function. In this study, a conceptual hydrological green roof model was developed based on the Penman-Monteith method and water balance theory. The model was calibrated and verified with continuously observed meteorological and hydrological data of a green roof in Beijing, and then applied to simulate evapotranspiration processes of green roofs located in various climatic zones. The results show that the hydrological model could accurately simulate evapotranspiration process of the green roof, with the Nash-Sutcliffe Efficiency Coefficient of 0.6385 and 0.6014 as well as the Determination Coefficient of 0.7191 and 0.6168 for calibration and verification, respectively. For green roofs with the same depth of substrate, daily average value of actual evapotranspiration (AET) increases as the climate changes from semi-arid (Lanzhou) to semi-humid (Beijing) and humid (Guangzhou and Wuhan). Increasing depth of substrate results in the increased AET from green roofs, but the daily average AET from green roofs changes marginally when the depth of substrate increases beyond thresholds. The thresholds of substrate depth of green roofs at Lanzhou, Beijing, Wuhan, and Guangzhou are 10 cm, 17 cm, 24 cm, and 25 cm, respectively. The daily average AET of green roofs located in different climate zones also have various thresholds, and the daily average AET threshold of green roofs at Guangzhou is in turn larger than that at Wuhan, Beijing, and Lanzhou. This study is expected to provide a scientific reference for estimation of green roof evapotranspiration and design of green roofs under different climatic zones in China.