The XVIII International Conference on Mine Surveying

60 / 2023-03-31 11:34:31

Pointwise Modelling and Prediction for Ground Surface Uplifts in Abandoned Coal Mines from InSAR Observations

Prediction for Ground Surface Uplifts,Abandoned Coal Mines,the varied Weibull CDF,InSAR Observations

Interferometric synthetic aperture radar (InSAR) is a useful tool for monitoring surface uplifts due to groundwater rebound in abandoned coal mines. However, InSAR-based prediction for surface uplifts has rarely been focused so far, hindering the scientifical assessment and controlling of up-lift-related geohazards in a wide area. In this study we firstly revealed that the temporal evolution of surface uplifts caused by groundwater rebound at a surface point approximately followed an exponential distribution. Following the result, a varied cumulative distribution function (CDF) of Weibull distribution was then used to model the temporal evolution of surface uplifts on a basis of point-by-point. Finally, the parameters of the varied Weibull CDF were inverted from historical InSAR observations of surface uplifts and forward used to predict uplift trends. Two abandoned coal mines in Beipiao city, China, were chosen to test the presented method. The results suggest that the varied Weibull CDF is able to well describe the processing of time-series uplifts, and the root mean square errors of the predicted uplifts are about 1.2 mm. The presented pointwise method predicts surface uplifts based on historical uplift observations and a mathematical func-tion (i.e., the varied Weibull CDF), without the requirement on in situ geological and hydrological information about the focused abandoned coal mines. Therefore, it offers a new tool for predicting surface uplifts in wide abandoned mines, especially in the case that in situ geological and hydro-logical information is lack.