Studies Of Greening's Effects On Outdoor Thermal Environment Of Multistory Residential Building

Human residential activity is named as the first activity of city in Athens Charter. The construction of residential district is regarded as the vital event and the important part of city construction by any countries and areas. Whether the environment of residential district is comfortable is a key symbol of economic development, society advance and civilization level. But in china, because of the lack of theory and practice, we have been copying the construction model of western countries in a long period which pay much attention to the landscape visual effects but neglect the feeling of the residents. As one of the most important elements of residential physical environment, thermal environment is closely linked with the residents' life. At present, the domestic and abroad research mostly focus on comparing the effects of different greening forms making on thermal environment and simulation research with computer model, but the whole research about greening's effects on outdoor thermal environment in the scale of residential district is less. This paper takes Shanghai as an example to do the quantitative research that how greening makes effect on outdoor thermal environment of the multistory residential districts in the method of on-the-spot survey. The conclusions are as follows:(1)The effect of different green forms on temperature of residential district center plaza mainly happens from sunrise to sunset in winter. From sunrise to noon, the values of temperature in the lawn and defoliation trees plaza are gradually higher than the evergreen trees plaza, and the temperature represents lawn plaza> defoliation trees plaza>evergreen plaza.(2) The daily average temperature of three green form plazas are: lawn plaza (6.61℃)> defoliation trees plaza (6.29℃)> evergreen trees plaza (5.79℃). So the lawn plaza and defoliation trees plaza can increase temperature from 0.27℃to 1.16℃.(3)The daily change of body comfort index is mostly same as temperature, and the differences of body comfort index among three plazas mainly appear from sunrise to sunset. It represents lawn plaza > defoliation trees plaza >evergreen plaza.(4) The daily average body comfort index of three plazas represent lawn plaza (6.70℃)> defoliation trees plaza (6.65℃)> evergreen trees plaza (5.94℃). So we think the lawn plaza and defoliation trees plaza can supply more comfortable outdoor environment in winter. Consider with shading in summer, defoliation trees is the most fitness green form in residential district plaza in Shanghai.(5)Among 5 indexes, we find there are very negative correlations between the radiant heat with area ratio of multi-layers communities, and coverage of trees.There are very significant negative correlations between the temperature with green coverage, area ratio of multi-layers communities and coverage of trees.The THI has extremely significant negative correlation with area ratio of multi-layers communities. THI has significant negative correlation with green coverage and coverage of trees.(6)Four regression equations between radiant heat area and ratio of multi-layers communities are extremely significant. Four regression equations between radiant heat and coverage of trees are also extremely significant.Four regression equations between temperature and green coverage are all extremely significant. Four regression equations between temperature and area ratio of multi-layers communities are extremely significant too. The linear regression equation and exponential regression equation between temperature and coverage of trees are extremely significant.Four regression equations between THI and area ratio of multi-layers communities are very significant. Four regression equations between THI and green coverage are significant. The linear regression equation and exponential regression equation between THI and coverage of trees are significant.(7)There are extremely significant negative correlations between the tridimensional green biomass with temperature. Those between the tridimensional green biomass and THI and radiant heat are significant negative correlation.(8) Four regression equations between temperature and tridimensional green biomass are all extremely significant. Four regression equations between radiant heat and tridimensional green biomass are all significant. Four regression equations between THI and tridimensional green biomass are all significant.(9) There are significant positive correlation between temperature and the density of green patch. The average area of patches with temperature and THI are significant negative correlation.(10) Four regression equations between temperature and green patch density are all significant. Four regression equations between temperature and average area of patches are all significant. Four regression equations between THI and green patch density are all significant. Four regression equations between THI and average area of patches are all significant also.(11) The stepwise regression model between main factors which make effect on thermal environment and radiant heat is y=-1.02x1-0.05x2+0.24, and x1 is the area ratio of multi-layer communities, and x2 is the tridimensional green biomass. The test of the equation and coefficients are extremely significant.The stepwise regression model between main factors and temperature is y =0.0029x1 -5.01x2 -0.17x3+34.13, and x1 is the green patch density, and x2 is the area ratio of multi-layer communities, x3 is the tridimensional green biomass. The test of the equation and coefficients are also very significant.The stepwise regression model between main factors and THI is y=-1.77x1+29.8, and xl the area ratio of multi-layer communities. And the test for the equation and coefficients are extremely significant also.