Study On Farmland Classification Data Generalization Based On GIS

The evolution of the computer technology facilitated the development of cartography, and caused a huge revolution of various technique of cartography. It also made GIS gradually penetrate into each section of the national economy and play an important role in it. As an important part of GIS, lots of researches have been done on generalization by specialists and also have some achievements.At present, special element-oriented cartography generalization is one of the focus of the GIS research and application. Farmland classification data cartography generalization is a particular case in special element cartography generalization research. The realization of cartography generalization needs follow geography data generalization rules to solve the conflictions caused by reduction of expressive space. At the same time, special distribution law of farmland classification is also an important influence element of cartography generalization.The theory of generalization and farmland classification has been firstly introduced and the characteristic of farmland classification data and styles of farmland classification integration are also analyzed in this paper. In the following parts, the generalization regulations for the farmland classification integration and how to combine with generalization operations are discussed in detail in the paper, such as including importance of geographic objects regulation, geographic objects selection regulation, combination regulation, aggregation regulation, fusion regulation, and shape generalizing regulation. Then taking the farmland classification data of Qianyang as an example, based on the generalization function and the spatial analysis function of GIS, through which, the application of generalization rules are proved; as the result, an applicable method has been formulated and could be used for the farmland classification, both at province level and country level.In the last part of this thesis, conclusions have been made to evaluate the work of this thesis, and to indicate the pitfalls.