Quantitative Measurement Study On Tridimensional Green Biomass Of Forestry Based On RS

Urbanization is the inevitable product of today’s social development, which charged with various functions necessary for human production and life. With economic development, spatial expansion, population growth and improvement of living standards, the accelerated process of urbanization has also brought a series of ecological and environment problems. Establish reasonable scientific forest ecosystems, and increase the amount of urban green space has become an urgent need. Seek man in harmony with nature to achieve the sustainable development of the city and the environment has become the direction of urban development.In paper,16districts in Beijing were considered as a study area. SPOT5remote sensing image was data source, SPOT5image as the data source, extracting the vegetation of remote sensing image. Combined with integration technology of GPS, RS and GIS, collected the field data of tree, the model of three-dimensional green biomass of Beijing conifers and broadleaf has established by principal component analysis and stepwise regression method, which can calculate and analysis the three dimensional green biomass of Beijing. The main conclusions have been got:(1) The image of SPOT5has been selected, combined with aerial orthophoto image with the spatial resolution of0.6m, and then combination of supervised classification and visual interpretation methods has been used to do classification and extraction of the vegetation of Beijing. In this paper,2land types have been classified:coniferous forest and broadleaf forest. Verified by field survey points, conformity reached91%, which meet the modeling requirements. The tridimensional green biomass models of coniferous and broadleaf trees have been established by dealing with survey data of usual tree species, remote sensing and GIS information with multivariate statistical analysis theoretical knowledge. The broadleaf trees tridimensional green biomass model is: y阔叶树=-66.44+4.477x2-1.2552x4-0.029x9+0.007x9+0.00004x10. and coniferous trees tridimensional green biomass model is: y�'�叶树=-23.78-0.136x1+0.861x2-0.188x4+0.009x9+0.01x9+0.009x10. The correlation coefficient of models were0.876and0.936respectively obtained by analysis. Verified by field survey points, the modeling accuracy are85.21%and92.12%respectively. According to the studies of home and abroad, the model can be applied to practical when the accuracy above80%. The models can be estimated the tridimensional green biomass of arbor in Beijing.(2) The tridimensional green biomass of broadleaf trees and coniferous trees are got by calculated model based on SPOT5image. The tridimensional green biomass of each district, per unit area and per capita are also estimated. According to the analyses of figures and tables, Huairou District owns the largest amount, Xicheng District has the least. Huairou District has the largest of the tridimensional green biomass per unit area, but Tongzhou District has the least. Huairou District owns the largest of the tridimensional green biomass per capita, but Xicheng District owns the least. The annual output of oxygen, absorb carbon dioxide, absorb the amount of sulfur dioxide and dust deposition of forest vegetation has been estimated from the perspective of three-dimensional green biomass, and show that Beijing’s forest vegetation has played an important role in the urban environment eco-efficiency.