Land subsidence has caused serious and costly damage to the Taiyuan City. Some previous researches attributed the problem to excessive withdraw of groundwater. However

the explanation was challenged by the noncoincidence of the spatial patterns between land subsidence and groundwater exploitation. The monitoring data in the period of 1956-2000 show that the land subsidence spatially coincides with the groundwater depression on the whole

but deviates locally. In the present study

spatial heterogeneity of medium is used to explain the phenomena. The following factors are taken into account: patterns of accumulated clay soil thickness

configurations of clay soils and coarse soils

and mechanical properties of soils in different sub-zones and depths. It is found that: (1) the land subsidence centers deviate from the corresponding groundwater depression centers to the sides with thicker accumulated clay soils; (2) in the same intensity of groundwater withdraw

the subsidence volume is usually greater where clay interbeds are more and the individual interbed is thinner; and (3) the land subsidence is correlated closely with the mechanical properties of soils.