The Estimation Of Living Vegetation Volumein The Ring Park Around Hefei City Based On TLS And Landsat8

In recent years,the main methods for improving the urban ecological environment at home and abroad are to increase the introduction of green plants into cities,increase the volumetric capacity of stereo crowns,and promote the green development of cities.Because the characteristics of different plants are different,the differences in the crown volume?three-dimensional green volume?are greatly different,which directly affects their contribution to the urban green space.How to improve the green structure in the city and increase tridimensional green biomass is a problem that forestry and garden workers need to solve.In this paper,ground 3D laser radar,ArcGIS,GPS,measurement technology and other technologies are used as tools to collect and analyze the imagery and landscape maps of Hefei City's The Ring Park around Hefei City.The 3D laser scanning system is used to scan the trees and obtain them.Three-dimensional green volume,combined with remote sensing images to estimate the total amount of three-dimensional green volume in Hefei City's The Ring Park around Hefei City.First,coordinate positioning and 3D laser scanning of sample trees and plots,point cloud processing in 3D laser software,and obtaining complete single trees and sample plot data to obtain single tree's crown,tree height,DBH,and other tree measuring factors.,and with the traditional altimeter,breast diameter diameter measurement obtained by the forest tree factor error analysis;then,under the Matlab environment,through the programming to achieve single wood and sample plot above the first live branch volume calculation,and with the traditional way according to The individual tree volume calculated from the volume formula corresponding to the crown shape is used for error analysis,and the single-wood three-dimensional green volume model based on the extracted tree factor is constructed;finally,the sample crown canopy volume obtained from the Matlab environment is used as the dependent variable,and the Landsat8 remote sensing image is extracted for correlation.The band information is an independent variable,and a three-dimensional green quantity inversion model of Hefei City's The Ring Park around Hefei City is constructed to realize the estimation of the total amount of three-dimensional green quantity in The Ring Park around Hefei City.In combination with the current status of the tree species in the The Ring Park around Hefei City,the corresponding tree species allocation model is proposed for the The Ring Park around Hefei City.Green space is provided as a reference.The main findings are as follows:?1?Compare the forestry factors measured by the traditional field with the tree factors extracted by the 3D laser software,and the relative errors are all below 5%;calculate the canopy volume?ie,tridimensional green biomass?of the single tree through the traditional tree formula A comparison of tridimensional green biomass volume calculated by a series of software such as three-dimensional laser and the results showed that the average relative error of other trees was 4.90%except Cypress,Palm,Black Pine,and Downs fir.To meet the error requirements in forestry.?2?A method of“point cloud projection and grid segmentation and matching”is proposed,and the calculation of the crown volume of single plant and plot is realized through Matlab programming,and the volume of single wood calculated according to the volume formula corresponding to the crown shape in the traditional way is performed.Error Analysis.The factors such as crown height,crown width and DBH diameter extracted by HD₃LS_SCENE software were used as independent variables.The volume of single tree crown calculated by Matlab was used as the dependent variable.Tridimensional green biomass volume model of single-wood broad-leaved trees and coniferous trees and tridimensional green biomass volume estimation model ofbroad-leavedtreeswereconstructedrespectively.It is:V???=-231.917+39.558X1+9.752X2+3.762X3?TheVbroadleavedtreesare tridimensional green biomass volume of single-wood broad-leaved trees;X₁,X₂,and X₃ are the crown diameter,crown height,and diameter at breast height,respectively?;tridimensional green biomass volume estimation model for single-wood conifers is:V???=-121.054+28.837X1+6.892X2+0.282X3(V_conifersaresingle Tridimensional green biomass volume of the woody broad-leaved trees;X₁,X₂,and X₃are the crown diameter,crown height,and DBH of the trees,respectively).The model is validated by the test sample and the accuracy is over 90%.?3?Selecting Landsat 8 as a remote sensing image data source in the summer 2017with phase space resolution of 15m in the panchromatic range and spatial resolution of30m in the multispectral band,combined with ancillary data such as GPS coordinates and Google Earth remote sensing images.The methods of supervised classification and visual interpretation were used to classify and extract the vegetation information of Hefei City's The Ring Park around Hefei City.The results showed that the overall classification accuracy reached 83.4862%and the overall Kappa index reached 0.7594.Select vegetation-related bands and band combinations as factor variables,use multivariate statistical analysis and other methods to select variables,and construct tridimensional green biomass quantity remote sensing inversion model of Hefei City RingParkas:'V=251.339+0.490*BBlue-0.832*BNr+0.658*BRed+2.529*BSWIR1-2.597*BSWIR2 ?V'is tridimensional green biomass volume of the stand,and B represents each band?.Through the verification of the sample to test the model,the accuracy is above 85%.Combined with the results of remote sensing classification,the total three-dimensional green volume of Hefei City Park was 20,914,137.5 m³.