Topographic Change Detection In Opencast Mining Area Based On ZY-3 Satellite Images

Mineral resources provide basic energy for national economic construction and are the material basis for national progress and social development.The open-pit coal mine has a large production capacity and is an important part of China ’s coal industry.However,in the process of open-pit mining,it is often accompanied by surface deformation,resulting in the destruction of surface structure,which is easy to cause geological disasters such as landslides,debris flows,and collapses.It poses a great threat to the personal and property safety of the people in the mining area and the ecological environment of the mining area.It is of great significance for the sustainable development of mining area to detect the terrain change of mining area,understand the change process,obtain the change amount and analyze the change trend,which is helpful to prevent the geological disasters caused by mining.The open-pit mine is composed of open-pit mine and waste rocks piling field,which needs to occupy more land.The traditional manual measurement is not only inefficient,but also difficult to obtain the surface deformation of the whole mining area.With the rapid development of remote sensing technology,high-resolution remote sensing images have become an important data source for obtaining deformation information in mining areas.On January 9,2012,China successfully launched the first three-line array stereo mapping satellite,ZY-3 mapping satellite,which has a geometric positioning accuracy of better than 2m in plane and better than3 m in elevation,providing a more accurate data source for mining area change detection.According to the characteristics of high geometric positioning accuracy and wide coverage of ZY-3 satellite images,this thesis proposes a method to detect the surface deformation of open-pit mine area by using ZY-3 satellite images and DSM.The digital surface model(DSM)of mining area is reconstructed by satellite stereo images,and the surface deformation of mining area is obtained by registration and difference between multi-temporal DSM.The evaluation of surface deformation in mining area is realized by means of overall analysis,typical area analysis and profile line analysis of difference DSM.The research contents of this thesis include :1.The three-dimensional reconstruction of the DSM of mining area terrain is carried out by using domestic ZY-3 stereo images.For terrain reconstruction without ground control points,the method of using GLAS laser altimetry data to assist regional network adjustment without ground control points is studied,which improves the accuracy of terrain modeling without ground control.The experimental results show that the plane positioning accuracy of ZY-3 is about 2.54 meters and the elevation accuracy is about 2.9 meters under the condition of ground control points.Under uncontrolled conditions,the elevation accuracy is about 6.19 meters,and the elevation accuracy of the combined GLAS satellite laser altimetry data is about 2.75 meters.2.An extraction method of mining area terrain change based on DSM of satellite images is proposed.Based on the registration and difference between multi-temporal DSM,through the overall regional analysis,typical regional analysis,and profile line analysis method,the terrain change characteristics of the mining area are extracted and analyzed,and extraction of elevation change information,determination of change threshold,quantitative calculation and accuracy evaluation of changed area are realized.3.The application of domestic ZY-3 stereo images and its DSM in the detection of surface deformation in mining areas was carried out.Under controlled conditions,the multi-period ZY-3 satellite images during the mining and closure of Fushun Open Mine were selected for three-dimensional reconstruction of terrain to obtain multi-temporal DSM,and the elevation change information in the region was extracted and analyzed from the three levels of the whole,typical area and terrain profile,and the change trend was summarized.At the same time,the Shendong mining area was selected to carry out the application of ZY-3 image and its DSM for mining area change detection under uncontrolled conditions.By introducing GLAS laser altimetry data to assist the adjustment of ZY-3 image regional network,the elevation positioning accuracy can be significantly improved,and the application of domestic ZY-3 surveying satellite data in mining area change detection is further expanded.