Tridimensional Green Biomass Measures Of Wuhan Artificial Vegetation

Urban green land plays an important role in city environment improvement and environment quanlity enhancement,and urban greening is also an important aspect and index in comprehensive evaluation of key city environment.Because of the speciality of urban green land,in this article we try to modify the effective LAI by Hemiview on the basis of actual LAI by CI-203.Then,we want to calculate the tridimensional green biomass on the level of community and Remote Sensing Image by useing the modified LAI.We chose 28 plant species and establish modified equation of the effective LAI and the actual LAI.Data of 154 plots are used for modeling on community level and those of 39 plots for modeling on RS level.The results are as follows:(1) Modification of effective LAI of Hemiview canopy analysis system based on individual levels.Correlative analysis showed that there are very positive correlation between values of LAI by CI-203 Portable Leaf Area Meter and Hemiview canopy analysis system.The optimum regression equation of trees speces is y=2.28x^1.14;the optimum regression equation of shrubs and hurbs are y=5.77x-2.46 and y=4.32x-0.39 respectively.(2) The LAI models of communities based on community parametersThe regression equations of LAI and community parameters of the total community, the tree layer,the shrub layer and the herb layer are established respectively.We find that multiple regression equations are better than the simple linear regression equations.The multiple regression equations of the communities total LAI are better than the multiple regression equations of single layer LAI.So the optimum regression equation of the communities total LAI model is Y=exp(1.153+0.25 lnt₃t₄+0.05 lnt₆+0.005 t₂+1.109 t₅-0.08 lnt₅).We use the equation LVV=[exp(1.153+0.25 lnt₃t₃+0.05 lnt₆+0.005 t₂ +1.109 t₅-0.08 lnt₅)]*S for calculating the LVV of community.(3) The LAI models of green land based on characteristics of TM ImageCorrelative analysis showed that there are very negative correlation between the communities LAI and the DN values of band 1 to 4.We find that the multiple regression equations which are established by the communities LAI and the values of DN are better than the simple linear regression equations,there are also better than the simple linear regression equations which are established by the communities LAI and NDVI,RVI, NDGI.So the optimum regression equation of the communities LAI model for TM Image is y=2.283^*(lnx₃)²+0.003x₄²-0.009x₄^*lnx₁*lnx₂*lnx₃-0.361.Based on this model,we Calculate the communities LAI for TM Image using ArcGIS and divided values of LAI rank,such as＜7.000,7.000-13.000,13.000-18.000,＞18.000.The results showed that the most values of LAI are concentrated in the range of 7.000-13.000.The maximum value of LAI is distributed in the Northeast,North, Northwest and Southwest of Wuhan City,and the minimum value of LAI is distributed in the central area..