Abstract:According to the modeling problem of non-equidistant subsidence data sequence, the application of three kinds of non-equidistant GM (1, 1) models in subsidence prediction is discussed. The analysis results show that the weighted non-equidistant GM (1, 1) model is not appropriate for the subsidence data with approximate exponential trend, and the grey linear weighted non-equidistant GM (1, 1) model is not a really equidistant model. The prediction formula of the grey linear weighted non-equidistant GM (1, 1) model has nothing to do with the time, and cannot be used for subsidence prediction. The fitting function of the non-equidistant GM (1, 1) model established by the author is equivalent to that of grey linear regression combined model, and can be used on the subsidence data with approximate exponential trend. Finally, the effectiveness of the three kinds of non-equidistant GM (1, 1) model are compared by example analysis and this validates the correctness of the above viewpoints.