Application Of UAV Tilt Photography In Monitoring And Evaluation Of Open-pit Green Mine Construction

The mining of mineral resources in China is mainly extensive mining,especially in the process of open pit mining,the damage to geology and ecological environment is inevitable,which requires strengthening the supervision of mining.The construction of green mine takes the sustainable development of mining industry as the core,which can effectively reduce the problems and disadvantages brought by mining.Based on the development and utilization of mineral resources in China and the requirements of relevant departments for mine supervision,UAV tilt photography,a remote sensing monitoring means with strong mobility,high resolution,pertinence and low cost requirements,is very necessary for mine monitoring.The research content of this paper involves three aspects :(1)The UAV tilt photogrammetry experiment was carried out in an open pit mine in Chongqing,and results of DOM,DSM and 3D model were obtained,On the basis of this result,DOM is established from the two aspects of field identification and image interpretation signs,and is applied to mine interpretation in a district of Chongqing.(2)According to the interpretation results,survey information and relevant materials,refer to Chongqing Green Mine Construction Standard Evaluation Index System,entropy method and synthetic index method are used to evaluate the green mine construction in a certain area.(3)In view of the mining order problems in the process of green mine construction monitoring,how to describe quantitatively is discussed,and the direct volume method is used to estimate the amount of mining beyond the boundary.The main conclusions are as follows:(1)UAV tilt photogrammetry has strong practicability and high accuracy in the monitoring of open green mine construction,and its relevant accuracy requirements can be met.The specific work flow of UAV includes preliminary preparation,fieldacquisition,internal processing and field verification.The DSM elevation error obtained by field verification using RTK is 18 cm at the maximum and 2cm at the minimum.The largest point elevation error is caused by the mining behavior during the period of RTK verification taken by UAV.The plane error of DOM is at most 5cm and at least 2cm.(2)The interpretation logo based on DOM of UAV is established.From the application results,the establishment of interpretation marks is relatively successful,and the overall accuracy rate is 94% after field verification.The correct interpretation rate of stope and solid waste can reach 100%.It can guide the extraction of green mine construction elements and promote the accuracy and efficiency of information extraction.(3)According to the "Chongqing Green Mine Construction Standard Evaluation Index System" and the specific mine environment selection index,the entropy method and comprehensive index method are used to evaluate the green mine construction in a district of Chongqing.The results show that the BXK mine has the best green construction and HY mine has the worst.According to the field investigation results,the evaluation results accord with the actual situation and are scientific,which can provide guidance and reference for the monitoring and evaluation of green mines.Within the evaluation index,there are also differences in green mine construction,The comprehensive score of mining environment,energy conservation and emission reduction,geological environment treatment and restoration is low.Therefore,in the future green mine construction,it is necessary to strengthen mining environment construction,energy conservation and emission reduction construction,and geological environment treatment and restoration.(4)DSM based mining quantity estimation is based on relevant practical experience.Using the direct volume method,the estimation of the transboundary production under two different conditions is discussed.The results show that the estimation of transboundary mining amount by using the revised DSM to eliminate the excess surface features reduces by 749.1t,and the estimation of transboundary elevation mining amount increases by 461.9t.From the perspective of total volume,the transboundary mining amount estimated by DSM after eliminating the excess surface features is more accurate than the transboundary mining amount obtained by using DSM directly to estimate the volume.acquisition,internal processing and field verification.The DSM elevation error obtained by field verification using RTK is 18 cm at the maximum and 2cm at the minimum.The largest point elevation error is caused by the mining behavior during the period of RTK verification taken by UAV.The plane error of DOM is at most 5cm and at least 2cm.(2)The interpretation logo based on DOM of UAV is established.From the application results,the establishment of interpretation marks is relatively successful,and the overall accuracy rate is 94% after field verification.The correct interpretation rate of stope and solid waste can reach 100%.It can guide the extraction of green mine construction elements and promote the accuracy and efficiency of information extraction.(3)According to the "Chongqing Green Mine Construction Standard Evaluation Index System" and the specific mine environment selection index,the entropy method and comprehensive index method are used to evaluate the green mine construction in a district of Chongqing.The results show that the BXK mine has the best green construction and HY mine has the worst.According to the field investigation results,the evaluation results accord with the actual situation and are scientific,which can provide guidance and reference for the monitoring and evaluation of green mines.Within the evaluation index,there are also differences in green mine construction,The comprehensive score of mining environment,energy conservation and emission reduction,geological environment treatment and restoration is low.Therefore,in the future green mine construction,it is necessary to strengthen mining environment construction,energy conservation and emission reduction construction,and geological environment treatment and restoration.(4)DSM based mining quantity estimation is based on relevant practical experience.Using the direct volume method,the estimation of the transboundary production under two different conditions is discussed.The results show that the estimation of transboundary mining amount by using the revised DSM to eliminate the excess surface features reduces by 749.1t,and the estimation of transboundary elevation mining amount increases by 461.9t.From the perspective of total volume,the transboundary mining amount estimated by DSM after eliminating the excess surface features is more accurate than the transboundary mining amount obtained by using DSM directly to estimate the volume.In this paper,uav tilt photography is applied to the monitoring of open limestone mines.From the perspective of application effect,the monitoring results in this paper have high precision,which can meet the needs of mineral mining order and green mine construction supervision,and provide technical support for green mine supervision.