221 / 2023-09-27 11:47:42

SBAS-InSAR monitors surface deformation in open pit mines and serves as an early warning tool

SBAS-InSAR;,Surface deformation,forewarning

In the process of open-pit coal mining, the slope instability may endanger the safety of the workers and delay the progress of the project, resulting in huge losses. In this case, the landslide warning system for open pit mining area is an important tool to reduce the impact of sudden surface collapse on mining, and the detailed deformation information of open pit surface can be used as an important reference to understand the stability of mining area. Due to the characteristics of InSAR technology, such as high precision, high spatial and temporal resolution, all-weather and all-weather, it is very suitable for a wide range of terrain monitoring, such as urban monitoring, mine monitoring, earthquake monitoring, volcano monitoring and so on. InSAR technology has been developed rapidly as a means of mining subsidence monitoring. InSAR technology is not affected by weather conditions and can effectively overcome the shortcomings of conventional monitoring methods. In this paper, the small baseline subset-interferometric synthetic aperture radar (SBAS-InSAR) technique is applied to the ground subsidence monitoring of Baorixile open-pit mine. SAR images (245 images in total) of Sentinel-1 orbit covering study area were compared with Planet optical images, and the inverse velocity method was used to predict the time of landslide occurrence in mining area. It is found that from January 2, 2017 to December 19, 2021, the maximum cumulative settlement of Baolixile open-pit mining area reaches 727.6mm, and the maximum subsidence speed is greater than 300mm/a. The instability time of the mine is April 30, 2020. a short-term simple moving average (SMA) is used to smooth the data of the point of interest and the stable displacement rate time series is obtained. The fitting line is made by using the inverse velocity method. The predicted landslide occurred on April 29, 2020, with an error of about 1 day from the actual landslide occurred on April 30, 2020. Considering that the Sentinel-1 satellite revisit time is 12 days, the nearest data from the landslide time point, that is, the data on April 28, is deleted, and the predicted result is April 19. It is of practical significance to advance the forecast time by ten days. The feasibility of predicting slope instability in mining area by displacement time series is proved. The correlation analysis is carried out by using the two orbital image results, and the same conclusion is obtained by cross-comparison. This technology still has some limitations, the image data acquisition time interval is too long, if the satellite data with shorter revisit time and higher spatial resolution can be obtained, the prediction results will be more accurate.