Study On Tridimensional Green Biomass Estimation And Analysis Of Forest In Beijing

In this paper, tridimensional green biomass of forest in Beijing has been estimated and analyzed based on remote sensing and geographic information system, which can be meaningful to the development of urban forest in Beijing.Landsat TM images dated by May,2009 have been used as the data source to do vegetation classification of Beijing. Integrated with the sample survey data, the method of multiple regression analysis has been used to establish the inversion model to estimate the whole tridimensional green biomass of trees all over Beijing. The model was set up based on the relationship among grey scale values of GIS information like terrain. Finally, the tridimensional green biomass of the forest in Beijing has been estimated with rather ideal estimation accuracy, the result also has been displayed in virtual expression as well. The main results are as follows:(1) Based on the sample survey data collected in July and August,2009 in some parts of Beijing and TM images, the method of typical sampling and principal components analysis have been used to estimate the tridimensional green biomass of forest in Beijing. The results from the established models of coniferous forest, broad-leaved forest and mixed forest have reached the precision of 80.84%, 83.92%and 87.97% respectively, verified by some of survey data. The estimation results are ideal.(2) Combined with the vegetation classification, the estimation models have been used to calculate the value of coniferous forest, broad-leaved forest and mixed forest and the results were 278145.56* 104 m3,2215955.53*104m3 and 1804755.43104m3 respectively. Therefore, the total of tridimensional green biomass of forest in Beijing was estimated to be 4298856.51*104m3. In addition, a grading graph has been made under GIS platform based on tridimensional green biomass of forest in Beijing.(3) According to the models, vegetation classification graph and administrative zoning of Beijing, the dimensional green biomass of 16 districts of Beijing has been got. The Huairou District owns the highest tridimensional green biomass, average tridimensional green biomass, as well as the per capita tridimensional green biomass, by referring to annual statistics of Beijing in 2009.(4) Combined with the annual statistics of Beijing in 2009, and the estimation results from above, the environmental benefits of forest from mountainous districts of Beijing have been analyzed by calculating carbon dioxide absorbing, oxygen producing, sulfur dioxide absorbing and dust particle absorbing. As the Beijing's ecological conservation development zones, the mountainous districts have been playing important roles in urban environmental protection and improvement.