A grey model GM(1,2) is modified as GM(1,2,M,N) based on analysis of possible time-lag effect and non-linear relation between ground subsidence and groundwater extraction.

• 通过分析地面沉降过程与地下水开采量之间可能存在的时滞性以及非线性关系,将原有的灰色GM(1,2)模型改进为灰色GM(1,2,M,N)模型。