Study On The Numerical Simulation Of Land Subsidence In Cangzhou Area

Land subsidence is some kinds of geological disaster.Some of these are caused by the human beings' engineering activities,others are controlled by the natural factors.It is also a regional geological phenomenon with the extensive lost of elevation and results from the interactions by soil releasing water,which is basing on the compaction of the Cenozoic layers.The Huabei Plain has suffered lots of problems causing by the land subsidence as the result of overdrawing water since 1960 s,besides facing with the funnel of water level.Cangzhou located in the north of Huabei Plain,with over 3200km2 area which had an accumulated reduction of elevation larger than 800 mm.In the center of Cangzhou,it has been over 2500 mm.As the development of district among the Beijing,Tianjing and Hebei in these years.More and more environmental problems had suddenly appeared.In the case of controlling the using of groundwater by the government of Cangzhou,it's getting a little bit better than last years in the center of city.But the area of land subsidence is still extending quickly.In order to monitor the land subsidence and control it better,It's necessary to analysis its' history and characters by the way of simulating the process.It's also has become a main task of the land subsidence research in recent years.In this research,thanks to the previous study,the first target is to analysis the principle of soil deformation in Cangzhou area,which contains the changes of soil's physical properties and the compaction of aquifers with the depth.The second part are some special experiment on soil's characters of compaction,which shows the range of interbed and the effects from the variation of groundwater head.The elastic storage and inelastic storage also can be calculated out in the consequence of the relationship between deformation and stress.In conclusions of these thesis,A three-dimensional simulating of groundwater system in Cangzhou area could be found,by considering the geological conditions and using the Modflow in GMS.10.0.The model is based on the datas from 2005 to 2012.With the sub package,It's improved to be a one-dimensional simulating of land subsidence.Rely on the elevation observations in 2012,After adjustment of parameter and interbed,A basal model has been finished.At last,through the analysis on some characters of land subsidence in Cangzhou region,combining with all kinds of experiment,the simulation of aquifer compaction can be divided into Delay system and No-Delay system by using the SUB package,Which is more accurate and meaningful to the future land subsidence prediction.