The Research About The Control Of Geological Structure Of Karst Groundwater In Eastern Ordos Basin

Tianqiao Karst system is located in the east of Ordos basin,which is a important water supply source of energy and chemical industry base in the north of Shannxi.This system has many features such as large area,rich water resource,better water quality and so on.Learning geological structure is a key method to study this system.At first,the paper learns the current situation and development of the theory of the distribution of groundwater controlled by geological structure.At the basis of exploration results of Tianqiao karst system,the theory can be used in the research further more.We conclude the development situation of geological structure,the hydrological condition of this region,then analysis a series of infuence that geological structure force on the aquifer,such as the recharege,draining and streamflow of the aquifer controlled by structure,the enrichment regularity of groundwater controlled by faults,folds and so on.At last,we evaluate the resource of groundwater by water balance method and numerical method.In this paper,the above study has been made aware of the following points:1.Caledonian movement controls the sedimentary and thickness of the aquifer in Tianqiao Karst system,which also controls the rocks of this aquifer.2.Yenshan movement is the dynamic factor of Tianqiao karst system,which make the shape of the aquifer like a spade inclined to west and controls the boundaries.3.Neotectonic movement controls the recharge,draining and streamflow of the aquifer. The rise and fall of the earth's crust and the erosion power make carbonate rock bare surface, which accept rainfall.The cutting power of Yellow River reach the top roof of the aquifer, which form the drainage datum plane.4.The occurrence of rocks,faults and folds control the direction of streamflow.Tianqiao anticline,the bending in the west of Shanxi,Qinshui river graben,Sunjia river graben form the draining zone of groundwater.5.The faults control enrichment regularity of groundwater in draining zone.There are many springs and rich groundwater near the normal faults.6.Through water balance method and numertical method,we evaluate the resource of groundwater in Tianqiao Karst system is 168.77×10~4m~3/d,the recoverable resource is 133.55×10~4m~3/d,the recoverable resource in the west bank of Yellow River is 60×10~4m~3/d.