The Relationship Between Microclimatic Factors And The Different Structures Of Green Land In The Yuhuatai Scenic In Nanjing

With the development of urbanization, environmental problems become increasinglyprominent. Urban green land has a significant effect on eco-environment improvement, butdifferent structures of green land have quite different effects on it. To Study on the relationshipbetween the structures of green space and microclimatic factors, we chose three kinds of greenland with different internal structures as test objects: tree-shrub-herbage structure, tree-herbagestructure and shrub-herbage structure, in the typical green land-Yuhuatai scenic area in Nanjing,then according to their structural characteristics, we monitored the time-variations of luminosity,temperature, surface temperature, wet-bulb temperature(humidity) and NAI concentration ofthese green land, analyzed the differences of the microclimate factors between the differentsamples and compared their microclimate factors’ diurnal variations and seasonal variations.The results showed that:1.Different structures of green land had different light-shading effects. Tree-shrub-herbagestructure had the strongest light-shading effect in spring, summer and autumn, shrub-herbagestructure took second place, and tree-herbage structure was the worst; Due to the decrease ofvegetation quantity, shrub-herbage structure had the worst light-shading effect,tree-shrub-herbage structure took first place and shrub-herbage structure took second place.2.Green land had cooling effect both on atmospheric temperature and surface temperature.In terms of cooling atmospheric temperature effect, tree-shrub-herbage structure>shrub-herbagestructure>tree-herbage structure in spring and autumn; tree-herbagestructure>tree-shrub-herbage structure>shrub-herbage structure in summer; they had the similareffects in winter, but its fluctuation range was higher. In terms of cooling surface temperatureeffect, tree-shrub-herbage structure>shrub-herbage structure>tree-herbage structure.3.Different structures of green land had different humidification effects. tree-shrub-herbagestructure had the strongest and fastest humidification effects in four seasons; in spring andautumn shrub-herbage structure>tree-herbage structure, in summer it is opposite; when therewas lack of illumination, shrub-herbage structure>tree-herbage structure, it is opposite whenthere was enough illumination.4.The NAI concentration reflected the air cleanness degree, and different structures ofgreen land had different air cleanness degrees. Tree-shrub-herbage structure> shrub-herbagestructure>tree-herbage structure in four seasons, in other words, air cleanness degreetree-shrub-herbage structure> shrub-herbage structure>tree-herbage structure.Tree-shrub-herbage structure had the air with the best air cleanness degree.5.Compared the changes of microclimate factors among different seasons in the samestructure of the green land, the three structures of the green land, tree-shrub-herbage structure,shrub-herbage structure and tree-herbage structure, had the best and the strongest light-shading,cooling and humidification effect in summer, the worst in winter. In summer, the illuminance extremum differences of tree-shrub-herbage structure is0.51times higher than tree-herbagestructure,1.70times higher than shrub-herbage; the temperature extremum differences oftree-shrub-herbage structure is1.02times higher than tree-herbage structure,1.88times higherthan shrub-herbage; the surface temperature extremum differences of tree-shrub-herbagestructure is0.91times higher than tree-herbage structure,0.96times higher than shrub-herbage;the wet-bulb temperature extremum differences of tree-shrub-herbage structure is0.98timeshigher than tree-herbage structure,2.06times higher than shrub-herbage; the NAI extremumdifferences of tree-shrub-herbage structure is2.26times higher than tree-herbage structure,1.23times higher than shrub-herbage;6.Tree-shrub-herbage structure was the ideal structure of green land to give a full play oneco-environment improvement, and its ecological effect played best in summer. If urban landarea was limited, We can enrich the green land stories and distribution to maximize theeco-environment improvement...