Gravitational effect of water circulation in the northwest Yunnan

Abstract

Water circulation is the main disturbance source against precise gravimetry measurement which is one of the principal means of geodynamic study. Some scientists studied the disturbance of water level changes in lakes and rivers and groundwater activities on gravity field. Taking water circulation as a whole and combining it with the hydrogeological conditions in northwest Yunnan mountainous area and the measured gravity data, this paper studies the features, connections of water circulation in atmosphere, on surface and under ground and its effect on gravimetric data. The main conclusions are as follows: 1) The water circulation in atmosphere has little direct disturbance on gravity field; 2) The change of lake water level may cause gravitational effect of (10–20)×10−8 m · s−2; 3) In the NW Yunnan, types of the groundwater are various, and its changes are complicated, it is necessary to study point by point. In general, its disturbance on gravity field in this region is about 10×10−8 m · s−2, less than that in plain area.