Designing The Evaluation Modules Of Groundwater Recharge In North China Plain

During the work of groundwater investigation and monitoring, vast data are often accumulated that have bulky amount, different types and complex structures. Researchers must do much maintenance work, such as editing, updating, inquiring, transferring, storage and handover during dealing with the data.On the other hand, the data on hydrology, weather, vegetation and even geologic condition are always variational, which need real-time update. Obviously, it is important and useful to establish a new computer responsible dynamically system for timely input, safe management, rapid processing and output of the data. Therefore, we have designed the evaluation modules of groundwater recharge.By integrating the database technique, second development technique of GIS, general data analysis method and 3-D graphic output technique realized by OpenGL to support the professional hydrological module, we designed the evaluation module of groundwater recharge. The evaluation sub-module of groundwater vertical recharge, as a part of whole module, a lamped parameter EARTH model has been developed and applied to calculate vertical infiltration recharge to groundwater in Luancheng and Dezhouof the North China plain. It is concluded as follows:(1)The evaluation module of groundwater recharge in the North China Plain has been developed successfully, which comprises sub-modules of database management, 2-D spatial data analysis and editing, 3-D spatial data displaying and the analysis of infiltration and recharge from the precipitation based on EARTH model.(2)During the realization of module design, it is very important to choose an applicable development tool. In the different environment, different method has itself advantage. It is the key of the system realization to use the most reasonable method. In this paper, all the programs are realized based on the Visual C++6.0, which has the advantages of agility and high efficiency compared with other advanced languages.(3)After comparing the three methods of Export/Import, Embedding and second integration development, the second development based on MAPGIS class libraries has been chosen in this system. The developing method of MAPGIS with Visual C++ has been studied and carried out. The functions of vector graph edit, chart layer management, map scan have been realized with the application of MAPGIS.(4)During the design, the database management system, Microsoft Access, was used to establish the database. AH data types are analyzed synthetically and designed to be stored in these tables: dot table, line table, section table, type table, enumeration table, note table, sequence table, and then the logical relationship between each two tables has been established exactly, which can assure the integrality of the data. For example, deleting of a record of weather station can remove all the data associating with it, which can avoid data redundancy. At the same time, the index table has been established, which can build the corresponding relationship between the geography entity, and layers, the geography entity and primitive ID to realize the binding of spatial data and attribute data and then make the layer data and attribute data visiting each other...