基于太阳热辐射变化的绿地类型对降温影响分析

Effects of Greenbelts' Variety Based on Solar Thermal Radiation on Temperature Drop

[目的]研究太阳热辐射变化下的绿地类型对降温的影响。[方法]对夏季居住区的5种不同绿地类型(大乔木、小乔木、灌木、草本和裸地)在同一太阳热辐射条件下产生的不同降温效果,及其随日进程过程中的变化规律进行研究。[结果]绿地中的温度变化主要随太阳热辐射强度的日变化而变化,但其中以大乔木为主的绿地,通过树冠层对太阳热辐射的吸收、转移和反射作用,较大缓解了下垫面的温度环境,其下垫面温度与太阳热辐射的相关性R=0.156,降温达1.9℃,而草坪下垫面温度与太阳热辐射的相关性高达R=0.820,降温仅0.6℃,两者的表层温度相比,草坪要比大乔木高2.9℃。[结论]该研究中绿地树冠表温与气温线性关系的建立有助于为今后对较大规模数量的绿地温度测量提供新的方法。

[Objective] The aim was to study on effects of greenbelts’ variety on temperature drop under solar thermal radiation.[Method] In residential regions,effects of temperature reduction by five varieties of greenbelts（megaphanerophyte,dungarunga,shrub,herbaceous plant and bare land） and changing rules with days under the same solar thermal radiation were researched.[Result] Change of temperature changed with intensity of solar thermal radiation in greenbelts,among which greenbelt of megaphanerophyte absorbed,transfered and reflected thermal radiation through crown canopy.Temperature of underlying surface was reduced accordingly,where correlation between underlying surface’s temperature and solar thermal radiation（R） was 0.156 and the temperature declined by 1.9 ℃.In contrast,correlation of temperature of underlying surface（of lawn） with solar thermal radiation（R） was as high as 0.820,but the temperature only declined by 0.6 ℃,the surface temperature of lawn was 2.9 ℃ higher than that of megaphanerophyte.[Conclusion] The established linear relationship between crown’s temperature and temperature actually provides references for temperature measurement of greenbelts at scale.