The fluctuation of most of the hydrograph in the deep aqueous system records the fluid pulsation in lithosphere and variation of the earth's crust. Many observations have verified that groundwater is an ideal information carrier of the crust. In this paper, the series of input (precipitation, air pressure, Earth tide etc.) and output (water level, artesian flow) of the deep aqueous system are studied by using the spectrum analysis and system theory. The application concepts of transfer function and the spectral structure of the hydrograph enrich the knowledge of the deep aqueous system. Two typical spectral structures of the hydrograph of the deep aqueous system are obtained by comparing with many waterbearing systems of the Jizhong depression. One is from well Ma1 7 and the other is from the well Xinze-5. Finally, the physical models of forming the spectrum of the hydrograph are constructed on the basis of the spectrum research on the deep aqueous system. 1
Problems and Background Conditions of the Study AreaIt has been a rather long time that groundwater is studied as a utilizable resource and detrimental factor of environment. Recently, the third research domain of hydrogeology, that is to consider groundwater as an information source of the crust and to feed back the research result of information to the aqueous systems, has appeared. The research achievelemts of this domain have enriched the knowledge of the aqueous systems.Deep (which generally refers to a burial depth over 500 m) groundwater regime usually refers to the groundwater level fluctuation resulting from confined aquifer deformation. It is the exterior presentation of aquifer stress and strain state. This kind of regime is distinctfrom normal groundwater regime which is formed under the influence of water bal-
