Applicability of two grey models in earth-surface subsidence prediction of mining area

Existing dynamic single-point subsidence prediction methods of mining area earth-surface are mainly based on traditional leveling measurement data, which have single monitoring mode, high cost and easily destroyed observation points, and cannot guarantee real-time of earth-surface deformation information. Moreover, application of grey model for earth-surface subsidence prediction is only for a single model and its applicability is not analyzed according to characteristics of the model itself. Taking 7221 working face of Yuandian No.2 Mine as an experimental zone, earth-surface subsidence value is measured by differential interferometry synthetic aperture radar technology, and then GM(1,1) and grey Verhulst model that describe the relationship between subsidence and time are built separately for predicting earth-surface subsidence value, so as to realize the integration of earth-surface subsidence monitoring and dynamic prediction of mining area. Through comparing and analyzing fitting and prediction results of earth-surface subsidence value between GM(1,1) and grey Verhulst model, the applicability of the two grey models in earth-surface subsidence prediction of mining area is obtained: GM(1,1) should be used for short-term prediction from beginning of mining subsidence to early active stage if subsidence value curve of single point is approximately unimodal; when earth-surface subsidence enters into decline stage and subsidence value curve of single point is in flat-bottom saturation, gray Verhulst model should be used for medium and long-term prediction.