Dynamic Change Of Forest Stock Volume Estimation In Beijing Based On Landsat

The total amount of forest resources in China is rich and diverse,the forest covers a wide area,and the distribution of forest resources is uneven.These characteristics increase the difficulty of forest stock survey.In the increasingly mature environment of remote sensing technology,the traditional methods of investigating stand volume need a lot of human and material resources to support,which can no longer meet the needs of people.Therefore,it is very important to apply remote sensing technology to the investigation of forest volume.In this paper,the Landsat remote sensing image data of Beijing is used as the data source to study and build the remote sensing inversion model of forest volume in Beijing area.Using Landsat remote sensing data to extract the forest land distribution information in Beijing,combined with field sample data,a total of 20 factors were selected for modeling,including vegetation index terrain and band combination factors.According to the internal relationship between the forest volume and each modeling factor,based on three different methods,the forest volume estimation model was constructed,which were multivariate linear regression,principal component regression and neural network.After comparing the advantages and disadvantages of each model,the multiple linear regression model was selected to estimate the forest volume in Beijing in 2008 and 2013,and the change monitoring and analysis were carried out.The precision of forest volume inversion of coniferous forest and the estimation accuracy of the two stands is 83.9% and 82.2% respectively.The estimated results are as follows: in 2013,the total forest volume of Beijing was 14.2533 million cubic meters,including 10.2374 million cubic meters of broad-leaved forest and 401.59 cubic meters of coniferous forest;in 2008,the total forest volume of Beijing was 12.6587 million cubic meters,including 9.0877 million cubic meters of broad-leaved forest and 3.5710 million cubic meters of coniferous forest.The results of change monitoring show that the forest accumulation in Beijing has increased by 1594600 cubic meters in the past five years,among which the four most obvious areas are Changping District,Chengliu District,Daxing District and Pinggu District.