Ecological Effect Assessment of Green Space in Different Urban Residential Districts

With four different residential districts and the Dragon Tower Square（control sampling point） in Harbin city as the research objects, using Membership Function Analysis Method, then three ecological targets were surveyed which were the noise reduction, the negative ion increment and the amount of dust absorption in July and August in 2019,to analyze the ecological effects of concentration green spaces in the different residential districts and the Dragon Tower Square.This experiment was done in order to research the ecological effects of green spaces.The results showed that the change trends of noise reduction, negative air ion（NAI） increment and the amount of dust absorption were different in different residential districts, different months and different time points in the same day by comparing the ecological targets between the residential districts and the Dragon Tower Square.The noise reduction（4.15,5.42,2.55,5.50 db）and the NAI concentration increment（187,139,170,215 per cm~3）of green spaces in the residential districts＞that in the Dragon Tower Square（2.44 db, 89 per cm~3）,the amount of dust absorption of green spaces in the Dragon Tower Square(2.29 mg·m^-3)＞that in the residential districts(2.09,1.41,2.59,1.80 mg·m^-3).The ecological effects were different in various environment based on the Membership Function Analysis Method in diffrent months, they were in the residential districts and the Dragon Tower square in July（0.20,0.22,0.15,0.30,0.07）＞those in August(0.19,0.16,0.13,0.29,0.11×10^-2).The ecological effects of green spaces in the residential districts（0.20,0.19,0.14,0.30）＞that in the Dragon Tower Square（0.03）,of which, Yuan Da Metropolis Oasis District（0.30） was the best.Therefore, green rate of green coverage, plant diversity, plant arranging pattern and the ratio to trees and shrubs had significant effect on the ecological effects of residential districts.