College of Landscape Architecture, Beijing Forestry University, Beijing, 100083 China ; School of Landscape Architecture, Zhejiang Agriculture and Forestry University, Lin'an, Zhejiang 311300 China.
College of Landscape Architecture, Beijing Forestry University, Beijing, 100083 China.
J Environ Health Sci Eng. 2015 May 14;13:43. doi: 10.1186/s40201-015-0195-x. eCollection 2015.
This study investigated the microclimatic behavior of different land cover types in urban parks and, the correlation between air temperature and land cover composition to understand how land cover affects outdoor thermal environment during hot summer.
To address this issue, air temperatures were measured on four different land cover types at four observation sites inside an urban park in Beijing, China, meanwhile, the land cover composition of each site was quantified with CAD, by drawing corresponding areas on the aerial photographs.
The results showed that the average air temperature difference among four land cover types was large during the day and small during the night. At noon, the average air temperature differed significantly among four land cover types, whereas on night, there was no significant difference among different land cover types. Results of the linear regression indicated that during daytime, there was a strong negative correlation between air temperature and percent tree cover; while at nighttime, a significant negative correlation was observed between air temperature and percent lawn cover. It was shown that as the percent tree cover increased by 10 %, the air temperature decreased by 0.26 °C during daytime, while as the percent lawn cover increased by 10 %, the air temperature decreased by 0.56 °C during nighttime.
Results of this study help to clarify the effects of land cover on urban outdoor thermal environment, and can provide assistance to urban planner and designer for improving green space planning and design in the future.
本研究调查了城市公园中不同土地覆盖类型的小气候行为，以及空气温度与土地覆盖组成之间的相关性，以了解土地覆盖如何在炎热的夏季影响室外热环境。
为了解决这个问题，在中国北京的一个城市公园内的四个观测点上测量了四种不同土地覆盖类型的空气温度，同时，使用 CAD 通过在航拍照片上绘制相应的区域来量化每个站点的土地覆盖组成。
结果表明，四种土地覆盖类型之间的平均空气温差在白天较大，在夜间较小。在中午，四种土地覆盖类型之间的平均空气温度差异显著，而在夜间，不同土地覆盖类型之间没有显著差异。线性回归的结果表明，在白天，空气温度与树木覆盖率之间存在强烈的负相关关系；而在夜间，空气温度与草坪覆盖率之间存在显著的负相关关系。结果表明，树木覆盖率每增加 10%，白天空气温度下降 0.26°C，而草坪覆盖率每增加 10%，夜间空气温度下降 0.56°C。
本研究的结果有助于阐明土地覆盖对城市室外热环境的影响，并可为城市规划师和设计师在未来改善绿地规划和设计提供帮助。
