Study On The Estimation Of Tridimensional Green Biomassby Remote Sensing In Arbor Forest

As the main body of terrestrial ecosystem,forests have important functions and benefits.Forest is also the largest,most complex,ecosystem with multiple functions and benefits on the earth.It plays a significant role in improving the ecological environment,optimizing the environment of social development,promoting the construction of ecological civilization and satisfying people's spiritual life.In the past,most of the forest research adopted the two dimensional evaluation indexes,such as green space rate,green coverage rate,etc.Compared with the two dimensional evaluation index like green space rate,the tridimensional green biomass analyzes the vegetation in a three-dimensional way,which can analyze the structure and ecological benefit level of the vegetation more fully and comprehensively.It can deepen people's understanding of vegetation research and provide deeper technical support for the researches like vegetation system biomass.In this study,the data were collected from 5 branches of Guangxi autonomous region's state-owned peak forest farm,including Liuli,Ping Fu,Yinling and Changke.Trees of the forest farm served as the research objects.Based on the actual situation of the research area,the trees were divided into four types,i.e,Young Eucalyptus,adult eucalyptus,broadleaf,and conifers.142 sample plots were established to measure the center coordinates of the sample plots,the leaf area index(LAI),the tree height,crown height,crown diameter and diameter of the tree,and calculate the three-dimensional green quantity of the sample plots.According to the central coordinates of the sample,the vegetation index of the sample is extracted from the remote sensing image of Landsat-8 satellite,and the three dimensional Green(TGB),the leaf area index,the three dimensional green quantity and the vegetation index are set up respectively.The optimum inversion model is selected by comparing the goodness of fit and the reverse precision of each model.It is used to estimate the three-dimensional green volume of arbor forest in the study area.The main research results are as follows:(1)from the overall results of fitting,the precision of the three dimensional green quantity and the vegetation index fitting model of each type is higher than the fitting model of the three dimensional green quantity and the leaf area index.(2)for the Young Eucalyptus vegetation,the fitting precision of the TGB-RVI two polynomial model is the highest,with the formula of y=81.007x2-288.791x+508.418,R2=0.685,and the precision of 83.3%.In the adult Eucalyptus vegetation group,the fitting precision of the TGB-MSAVI two polynomial model is the highest.The formula is y=458.193x2-331.351x+359.239,R2=0.662,and the precision is 82.6%;in the broad-leaved vegetation type group,the fitting precision of the TGB-RVI index model is the highest.The formula is y=1004.431e0.132x,R2=0.712,and the precision is 81.7%.In the coniferous vegetation type group,the precision of the TGB-MSAVI two polynomial fitting model is the highest,the common type is y=-7751.145x2+10306.689x-2266.615,R2=0.864,the precision is 86.1%.According to the research experience that the fitting precision higher than 80%can be applied,the inversion model of the fitting result can be applied into practice.