校园绿地夏季小气候效应分析

为评估不同绿地类型对校园小气候的改善作用, 尤其是对人体舒适度的影响, 选取北京大学校园内有代表性的4处校园绿地(半天然乔-灌-草、人工乔-灌-草、人工乔-草、人工草坪), 在2012年夏季7-8月对其内部温湿度进行连续32天的24小时同步监测。结果表明: 夏季高温季节, 各类型校园绿地相对于无绿化地面均表现出显著的降温增湿效应, 尤其是北京大学校园内的半天然林发挥着重要的生态调节功能; 在约1个月的观测期内, 各类绿地对人体舒适性均有一定的改善, 改善程度上呈半天然乔-灌-草>人工乔-草>人工乔-灌-草>人工草坪的趋势, 但效果并不如降温增湿效应明显; 从一天的不同时段来看, 早晚时段人工草坪的舒适度改善作用较为明显, 高温时段不显著。总体来讲, 北京大学校园内部分绿地夏季对舒适度的改善作用未根据其不同的功能需求得到充分发挥, 在未来校园绿地建设中应得到进一步关注。

Microclimate Effects of Campus Green Space in Summer

Four representative types of green space including tree-shrub-herbage semi-natural mixture, tree-shrub-herbage artificial mixture, tree-herbage artificial mixture, and artificial lawn were selected in the campus of Peking University to study the improvement effects of green space on campus microclimate, especially on the human comfort. The air temperature and relative humidity were measured every one hour from 0:00 to 24:00 every day for continuously 32 days during July and August in 2012. The results indicate that all types of green space show significant cooling and humidification effects compared with the concrete floor in hot summer. Among these, the semi-natural forests perform a very important ecological regulatory function. During the observation period, all types of green space improve the human comfort degree to a certain extent, which are ranked in an order of tree-shrub-herbage semi-natural mixture > tree-herbage artificial mixture > tree-shrub-herbage artificial mixture > artificial lawn, but the improvement effect is not as obvious as their cooling and humidification effects. From the perspective of the different times of a day, the comfort improvement of the green space is more obvious early in the morning and late in the evening than that at any other time of a day. As a whole, some parts of the green space in the campus of Peking University don’t give full play to the improvement effects of the campus comfort according to the various functional requirements in summer, which deserves further attention in the campus green space construction.