关键词: 城市绿地, 土壤重金属, 污染评价

Abstract: In this thesis,the present situation of heavy metals contamination and the physical and chemical properties of soils and the enrichment situation of heavy metals(Cd,Hg,Pb and Cr) in the vegetable body in the Harbin city greenbelt were investigated and evaluated.The results were showed as follows:The four heavy metals all polluted greenbelt soil by different degree in Harbin.The contamination of hydrargyrum was the most serious and reached the heavy contamination.The next contamination was plumbum,cadmium and chrome.By using single factor to estimate contamination situation of five zones in Harbin,its result showed that the contamination situation of cadmium and hydrargyrum was very serious in the public greenbelt.The contamination situation of plumbum was very severe in the road and traffic greenbelt.The content of chromium was very high in the suburban agricultural zone.The ranking order of the contamination situation was the public greenbelt>the habitation greenbelt>the road and traffic greenbelt>the suburban agricultural zone by method of fuzzy comprehensive assessment.The ranking order of the comprehensive index of ten greenbelt plants was Populus nigra>lawn>Juglans mandshurica>Syringa microphylla>Syringa oblata>Picea koraiensis>Salix matsudana>Ligustrum suave>Ulmus pumila>Acer negundo.The ranking order of the agricultural plants was soybean>cole>corn>alfalfa>broomcorn>paddy>bean;The strongest enrichment capability of the greenbelt plants was Syringa microphylla;the strongest enrichment capability to the hydrargyrum and plumbum of the greenbelt plants was Juglans mandshurica;the strongest enrichment capability to the chrome of the greenbelt plants was Populus nigra.The compound contamination sign exists in the soil between total cadmium,total hydrargyrum,total plumbum and chrome.The prominent correlation exists in total cadmium and total plumbum.The correlation coefficient was very lower between heavy metals in the plant body.The correlation coefficient was very prominent between cadmium and plumbum in the plant body.The correlation between plants and soil's heavy metal content of the cadmium was very prominent and others was very lower.The main contamination source of the hydrargyrum of plants and soils was the atmosphere dust of factory and gas in the Harbin's greenbelt.One of the contamination sources of the hydrargyrum was the fluorescent lamp.The universal application of the fluorescent lamp produces a lot of contamination of public greenbelt in the ice and snow days of Harbin.

Key words: city greenbelt, heavy metal, contamination assessment