Research Of Typical Environmental Pressure Factors In Carbon-sink Model Of Urban Landscape Vegetation

Urban green plants have the function of carbon fixation and oxygen emission. It plays an important role in elimination of the CO2produced by human and complement of oxygen for us. Urban green space carbon sequestration ability influences the development potential of the city. Therefore, obtaining the carbon sequestration of urban green space is of great significance for bearing capacity of the urban ecosystem and decision-making coping strategies. Urban environment with a complex diversity makes the calculation of plant carbon sequestration capacity or annual productivity has to consider all relevant environmental stress factors on plant growth. The high heterogeneity of urban plant growth environment makes the environmental stress factor information extraction more complex and increases the difficulty for quantification of impact to plants. Meanwhile, in order to ensure the efficient estimation of urban vegetation carbon sequestration capacity, the vegetation in the apparent growth of information (such as crown diameter), environmental stress factors (such as traffic pressure, building shadowing, etc.) and some other information need to be automatically extracted from remote sensing images.In this paper, we use remote sensing-driven model of plant carbon sequestration to solve the above problem and take the traffic pressure for example to discuss the impact of environmental stress on plant growth.Plant crown diameter extracted from remote sensing images can represent the vegetable biomass and annual growth. The traffic data which is able to be obtained from the GIS road information (including the number of lanes, road crossings, location, etc.) can be used as the source data to build the "traffic pressure field".So we studied the original traffic data of the automatic extraction and integration methods and then got the statistical relationship between the above two factors and certain climatic factors through multiple regression analysis. All of this provide a useful theory basis and a method exemplification for environmental Stress Studies.The period during1993and2006is an history period of rapid economic growth and acceleration of urbanization. This paper takes Shanghai Changfeng region for research instance and focuses on the effect of the traffic pattern, the traffic flow and the number of lanes on urban plants growth or carbon sequestration capacity in the period. Some main road in the study area widen in2000and2005,so establish respectively the traffic pressure field of1993and2006according to the road change. Plant crown diameter variables are obtained through interpreting the remote sensing image in1993,2000,2003,2005,2006.Using GIS technology to analyze the temporal and spatial variation of traffic pressure and the corresponding changes of plant growth. Under the influence of traffic pressure, the samples of camphor crown diameter have an average increase of3.5m, while the cedar crown diameter have an average increase of3m.Those crown diameter increment are both lower than that of sample without influence of traffic pressure. The traffic pressure index, precipitation are positive for the significance of regression equation in the stepwise regression analysis. The traffic pressure index extracted by remote sensing image should serve as a useful parameter in remote sensing-driven model of the carbon sequestration of urban green plants.