Extracting methods for height of restored vegetation in mining area based on LIDAR

Land reclamation and ecological restoration are important contents of green mine，and how to quickly monitor and evaluate the effect of ecological reconstruction are urgent problems need to be solved.The advanced airborne LIDAR (light detection and ranging)measurement system can obtain the vegetation parameter information of the mining area quickly and accurately，which is of great significance for environmental control and monitoring.In this paper，taking an open mine as study area，the UAV-LIDAR (unmanned aerial vehicle light detection and ranging) measurement technology is used to obtain the point cloud data of vegetation，then the CHMs (canopy height model) are established with three different methods which are Kriging interpolation algorithm，TIN (Triangulated Irregular Network)interpolation algorithm and IDW (Inverse Distance Weighted) interpolation algorithm，then the heights of tree are calculated based on the CHMs.To study the applicability of different interpolation methods for vegetation height extraction in this mining area，the values of extraction are compared with the in_situ measured samples.The results show that the accuracy of IDW interpolation algorithm is the highest.The determination coefficient R2 of the two selected plots is 0.763 and 0.617 respectively，and the root mean square error RMSE is 0.113 m and 0.130 m respectively.The next is the TIN interpolation algorithm，the R2 of the two plots is 0.744 and 0.599 respectively，and the RMSE of the two plots are 0.121 m and 0.135 m respectively.For Kriging interpolation，the R2 of the two plots is 0.736 and 0.534 and the RMSE is 0.120 m and 0.153 m respectively.The search also find that the change of relative flight height caused by landform difference will affect the accuracy of tree height extraction.The research finds that UAV-LIDAR can obtain high precision point cloud data of vegetation，then vege-tation parameters can be extracted through modeling.The information about vegetation can guide ecological environment management，so，UAV-LIDAR has a wide application prospect in the field of land reclamation and ecological restoration in mining areas.