| Based on the meteorological data of Zhengzhou city in 2015,the particle data of 9 monitoring stations and the remote sensing image data,the site for the 3 km of the landscape pattern of green space were monitored using GIS and Fragstats technology.Focusing on the temporal and spatial distribution characteristics of PM2.5 and PM10 concentration,the relationship between meteorological factors and its response to the heterogeneity of urban green space landscape,the correlation and difference between PM2.5 and PM10 concentrations in different scale domains of different seasonal landscape indices and vegetation community types were quantified by Excel2007 and SPASS software,the coupling relationship between each were investigated,than construction of ideal green space landscape optimization based on the mitigation of air particulate matter.(1)The study found that the daily dynamic of air particulate matter PM2.5 and PM10 concentration was basically similar to the change trend of " high in the morning and evening and the low in the afternoon ";monthly dynamics in the two average daily concentration change trend had great volatility and a certain irregularity,it was associate with the restriction of pollution emissions and meteorological factors;The monthly mean concentration change trends of the two years were the same,but in the same month,the PM10 concentration was significantly higher than that of PM2.5,heavy pollution of the weather was in the heating season in December,JanuaryFebruary,the burning of straw in October and more dust weather in March.Fine weather appeared in August,on the whole,the two concentrations are basically winter > spring > autumn > summer.(2)By contrast,in the space dynamics,the pollution levels in Zheng textile machinery,Cigarette factory,River medical university,Bank school were significantly higher than those in Water supply company,Forty seven high school,Gang Li reservoir.And the pollution levels in Gang Li reservoir had always been the lowest in four seasons;Accordingly,the maximum value of green landscape index LPI,IJI,AI in 9 monitoring sites were Gang Li reservoir(22.96?85.66?99.14).At 6.0 km× 6.0km within range,its urban green space occupied area was up to 37.388 percent,and the green plaque area in Zheng textile machinery was the smallest which occupied byonly 8.397%.(3)Meteorological aspects: PM2.5,PM10 concentrations were decreased significantly under the action of reduction,removal,erosion and diffusion in rainfall,windy weather,and had no hysteresis;The atmospheric visibility showed a clear downward trend with the increasing of PM2.5,PM10 concentrations and air relative humidity.When the concentration of PM2.5 increased from(68.00 ± 10.66)ug / m3 to(296.20 ± 20.25)ug / m3,PM10 concentrations increased from(87.95 ± 8.30)?g / m3to(398.21 ± 32.90)ug / m3,visibility was reduced from 8.499 km to 0.701 km,the rate of decline was as high as 91.75%;When the relative humidity between 0% and 19%,the atmospheric visibility was 27.155 km ± 6.36km;When the relative humidity increased to 80%-89%,the visibility was only 3.111 km + 0.24 km,the decreasing rate was 88.54%,it had significantly decreasing trend.The relative humidity and particle concentration of relevance under different humidity conditions were different,when the relative humidity was 60% or more,they had a significant positive correlation.(4)The response of PM2.5 and PM10 concentrations to the urban green space pattern under different spatial and temporal scales was different,overall,the larger proportion of the landscape proportion of green patches accounted for,the higher the advantage of large area green patches had,the better for more uniform patch distribution,mutual coupling relationship and the reduction of particle concentration.The strongest correlation scale domain was 4km×4.0km,namely centered on monitor site.With the increasing of scale domain,the reduction ability of green space to particulate matter concentration was enhanced.2 km was the highest,then slowly weakened.(5)Through further study on the relationship between the distribution form of green plants and the concentration of particulate matter,the arbor shrub herb type dust blocking effect was the best,the ground / grass was the second,grass type,shrub grass type was poor.The strongest correlation scale domain was also 4km×4.0km.The correlation and the degree of fitting between PM2.5,PM10 concentration in summer and the green landscape pattern,the plant configuration in different scale were the best.On the basis of the above research,the pattern of green space layout and the typically plant communities forms in park,green space and road green space were put forward to reduce particulate matter pollution under different scales,in order to provide a reference value for the regional mitigation of air pollution in the green space system planning. |
PDF Full Text Request