An Information System For Cultivated Land Fertility Evaluation Based On ComGIS

Under the guidance of system science theory, the technique of constructing information system for cultivated land fertility evaluation is approached in this paper, with theory and method of software engineering.On the side of method and technique of cultivated land fertility evaluation, Statistic analytics, fuzzy mathematics theory, gray system theory, analytical hierarchy process(AHP) are applied and it can quantify selected-factor of evaluation. So we can avoid subjectivity because of intuition in qualitative evaluation as possible as we can. On the basis of these some models of evaluation about choice of evaluating factor, the selected-factor weight calculation, the calculation of the scores for single factor, synthetic evaluation and classification for cultivated land fertility and so on, are built in this paper.The main content of this paper is designing and realizing the information system for cultivated land. It testifies its priority and feasibility to develop applied system based on ComGIS(component geographical information system) through introducing the principle and characteristic of component technology, the development and application of geography information system, the characteristic and software production of comGIS and so on. Spatial database, attribute database, and collectivity function are designed for evaluation system according to particular analysis of aim and assignment for cultivated land fertility evaluation and demand of user. By using object-oriented and component technology method, the information system for cultivated land fertility based on SuperMap component was developed in the development environment of Visual Basic 6.0, which comprises of management subsystem of spatial data, management subsystem of attribute data and classification subsystem.In view of current situation of a vast of analytical data and low efficiency in practical work of dividing evaluation units, "Grid-Overlay Analyst Method" is advanced to partition evaluation units step by step, thus breaking up the whole into parts and improving work efficiency in overlay analysis work.Lastly, the paper takes cultivated land fertility evaluation of Ningxiang county ofHunan as example and applies planned system into practice. It shows the system is convenient, stable, and it can save working time, improve work efficiency, and accomplish work on the cultivated land fertility evaluation.This merit of this research is combining forward CIS technique with theory and ways of cultivated land fertility evaluadon. The combination makes it possible to solve the difficult problem of space-overlay that can not be solved with the traditional information system. This system offers an high-speed and efficient tool for the evaluation and management of cultivated land fertility.