Groundwater Flow Numerical Simulation Based On Stochastic Hydrogeologic Structure Of North China Plain

With the complexity and randomness of spatial distribution of water-bearingmedia, it is a bottleneck to simulate groundwater conditions. This dissertation isprimarily attempt to study the development of hydrogeological structure andgroundwater numerical model based on geostatistical method.Above all, the research progress of geostatistics in related field are summarized,and traditional variogram-based geostatistical concepts and basic methods arediscussed simply, then transition probability approach and programme for interfacingwith its code are present in detail. The one emphasis is that the approach is applied toNorth China Plain, a large catchment covering an area of about 13.84×104km2. Theborehole data are generalized and classified according to 800 or so boreholes in theplain and a mesh with 4000*4000*2M is defined in the model, then transitionprobability/MARKOV chains is calculated to different distance of various lithology. A100-geological structure simulation model of North China Plain is established byusing sequential indicator simulation. The scale effect of model is analyzed and thecrosscheck of simulation results are made, which shows that the coincidence degree ofthe model is over 75%. Otherwise, the visualization of the structure model is made byprofessional plot software Tecpolt.The other emphasis is that how to integrate the stochastic simulation model withgroundwater numerical simulation model, and modify its structure for interfacing withMODFLOW-2000 programme;According to different topographical unit anddifferent depth, different hydrogeological parameters of various lithology arespecified and interface with VM, GMS and source program are also discussed.Based on random hydrogeologic structure, random groundwater flow model inNorth China Plain has been established, then its results are statistically analyzed, andcharts of average water level as well as water level variance are drawed. The authoralso analyzes the possible cause of the error and the ways to deepen research depth.Finally, groundwater forecast model of south-to-north diversion scheme in NorthChina plain has been established upon which water level changes are analyzestatistically, which show that water level recovery is considerable in some local zonesof cone of depression. The probability of water lever recovery for 7m is above 90% inNing Bo-long region. The probability of water lever rise for 10m is above 95% at thecentral of the cone of depression in Cangzhou and Hengshui area.This study indicates that regional and complex hydrogeological structure can bedepicted by geostatistical method, simulate the random numerical model, and analysegroundwater resources from the view of probability statistic.