PRELIMINARY STUDYING ON LEAKAGE RECHARGEMECHANISM TO CONFINEDFRESH WATER BY APPLYING SEMIPERMEABLEMEMBRANE THEORY

摘要

With a long time and over exploiting of underground water from the Quaternary aquifer zone II , the eastern plain ofrnTianjin, it is found that the more water-level in these area drops, the quicker the consolidation velocity in the strata is. However, itrnwas also discovered that the water level of saline groundwater above the aquifer zone II, without being exploited, had the synchronicrndynamic changing process as that of their underlying aquifer zone II, but different in fluctuation. Theses two aquifer zones have arnvery close mutual interaction. It is concluded by the study and researches that the surface water, underground saline water and deeprnfresh water are the integrated water resources system. Under alkaline condition, the compacted or condensed clay layers possess of arnproperty that can be used as semi-permeable separator and the osmotic pressure produced in saline aquifer zone is one of the mainrndrives to accelerate the infiltration of the surface water downwards. As the water level difference between the aquifer zone II and itsrnoverlying saline aquifers is more than the osmotic pressure, in saline aquifer occurs the leaky flow, which will lead to lower down thernlevel of shallow water in the ground. As a result, this process makes the shallow water that should be evaporated become into thernrecharge to the deep fresh water aquifers. Therefore, stopping mining groundwater or greatly reducing the mining from the aquiferrnzone II might lead to the new environmental geology disaster.