Geographic Information System Support Large-scale Agricultural Land Quality Evaluation Studies

In the recent years, with the increasingly serious problems of population, resource and environment, sustainable development has become a more important research area all over the world. At the same time, agriculture development has tended towards sustainable agriculture. This due to the need of reasonable development and protection of agricultural land resources. Sustainable agricultural development is an urgent solution to the reasonable development of agricultural land in China, in order to reach a optimum resources distribution structure, specially where the cultivated land is scare, and the contradiction of human and land is apparently prominent. Furthermore, Geographic Information System(GIS) has a big role to play data management and spatial analysis. So, it has become necessary to employ GIS in land quality evaluation. Applying GIS to land survey, management and evaluation has practical significance as described below. GIS manages both spatial data and attribute data, which is of benefit in searching, calculating, analyzing, updating and outputting and expertise knowledge. GIS can provide detailed implementation plan, technology consultation and assistant decision-making support. This research was conducted at Baishui Agricultural High-tech Modeling Garden(AHTMG) in Qu county of Zhejiang province. AHTMG is relatively small area, with homogeneous resources and consistent background. With the support of MAPINFO, ARC/INFO ARCVIEW software and EXCEL for windows, Basic Database in AHTMC has been established. And based on the database, the agricultural land quality evaluation has been attained as follows. ? basic database Establishment The design of database includes objectives, principle, demand, analysis, conception and logical structure designs, data classification and data coding. Mapping data is mainly managed and edited with the aid of M A P IN F 0, AR C I IN F 0. The latter is the tool for editing, establishing of topology for point, line and polygon features. The spatial database for mapping of landform, soil, soil nutrient, land use, planning, and attribute database have been established, while the statistical database have been founded in EXCEL software. Through the common 16 item, spatial database can be joined with statistical database. DEM model has been developed. ? Agricultural land quality evaluation Agricultural land quality evaluation was demonstrated in two main crops in the research area, namely the paddy rice and the orange. And it is studied with different nine evaluated indexes for each corp. Based on the two crops physiological growth demands, Fuzzy Integrated Method was applied to calculate the indexes function values, which include serial model, separated model and concept model. The weight values for the indexes were calculated with the help of main factor analysis and expert analysis methods. Finally, the integrated scores were counted using the Index Accumulation Method. The dispersed data could transform the continuous polygon data through inner-inset method with Kriging, and then apply with ARC VIEW to extract the landform indexes to get the ultimate index scores. The agricultural grade mapping has been finalized with the ARC VIEW software. The distinguished characteristics of this study include: ? Combined with the advantages of two softwares MAP1NFO and ARC/INFO were brought into full play, which decreased the work of digitalization and edit.