Design And Realization Of Testing Soil For Formulated Fertilization Information System Based On ComGIS In Hills Area In Sichuan

On the base of topography analysis and soil characteristics evaluation in hills area in Sichuan,using object-oriented system development method,component-based GIS technology of MapObjects and relational database technology, this paper organically linked graphics and data management system, completed development and integration of testing soil for formulated fertilization information system in County An in VisualBasic6.0. The system achieved the functions as basic map handling, land information query, topography analysis, soil fertility evaluation, recommendation of the program of fertilization, optimal calculation of fertilization and visual display of results, to provide foundation and technical support for fertilization and soil management in County An, simultaneously, to provide reference for development and realization of testing soil for formulated fertilization County information system in hills area in southwest China. The results are as follows:1.This research analyzed the current fertilization technology overview and the fertilizer recommendation system development at home and abroad.According to study of the actual conditions and user needs, this paper combined with soil testing and fertilizer technology requirements, analyzed the needs of the functionality of the system, performance, reliability, availability, data classification, data characteristics and estimate the amount of data needs analysis, etc and designed the general framework of the system and functional on this basis. The general framework build up with the system from the database, model algorithms, decision support, human-machine interface, functional modules. The function of system includes input and output module layer, data browsing module, data query module, data analysis results show module, fertilizer recommendation modules.2. Based on the general framework of the system design,this paper build the system database, including the spatial database and attribute database. Spatial database system included the basic geographic information, land use, soil type, sampling sites, soil nutrients, remote sensing, digital elevation image, three-dimensional virtual information data. The attribute database included two aspects of attribute data, one was to accurately describe the spatial data, name, type, length, precision, the scope of property value information, the data structure was according to the requirements of classification and coding of the date and the data dictionary, designed on each data item in field names, field types, field length, number of decimal places to build such property; on the other hand was used to provide the parameters of fertilization, including the fertilizer use of the towns, the basic information of the agricultural production, the basic data of field test data fertilization for the fertilization of library establishment. Based on the system database design, the paper completed the geospatial database, the attribute database, and the fertilizer model database. Among them, the geospatial database, was mainly through a digital map to establish topological relations in the form of construction; the property database used Microsoft Access2003 database management software to establish; the fertilization model library was established with the precise fertilization-related mathematical model knowledge, including the model scope of application, use, coefficient, calculation rules, the variable meaning of such knowledge, the main application was established with the nutrient balance method. The connection of the spatial data and attribute data, was mainly through a common Code field (keyword above) to connect related items.3.ON the base of compared the various GIS information system development model, this study used the visual development language of Visual Basic6.0 and the secondary development of MapObject 2.3 GIS components, constructed the fertilization information systems. This development mode of the component GIS, has many advantages of powerful, developing simple, small and flexible, low cost and organically linked the graphical management systems and the data management system, to overcome their own limitations so that the two were complementary of the basic realization and enhanced the application of the user intuitive, basicly realized access, query, analysis, consulting and other requirements from the information on soil testing and fertilizer. In the process of establishing human-machine interface, this study didn't use the interface design tool of Visual Basic6.0, but choosed the ActiveBar. It was a specially designed user interface of the ActiveX control, more simple, more integrated, developed by the Data Dynamics, made the user interface of the system more friendly, more convenient.4.The soil fertility in the quality of the study area changed significantly with the topography, taked Yong'an Anchang, Suishui as boundaries, the higher soil fertility was in the southeast hills, plains region, in the northwest, the fertility decreases with the increasing altitude of the low, middle mountain land. For the topographical features of the study area, comprehensived the consideration of the terrain, the cultivated land use types and the relationship between the three soil nutrients, according to the data sampling points, using the geostatistics, the spatial interpolation, evaluated the study area by the quality of soil fertility, reflected the quality of the spatial distribution of soil fertility status, the soil fertility of the real situation and determined, and fixed the fertilization program on this basis, improved the accuracy and reliability of the recommended fertilization.