面向对象的土地定级特征模型

采用面向对象技术的特征建模方法，通过建立土地定级的特征对象模型、特征字典模型、作用分值计算模型和定级的数据库模型，不但集成了定级因素来自几何和非几何两方面的信息，数据得到更有效的组织，数据完整性也更易于维护，而且不同土地用途类型的定级数据可混合处理，用地类型可变，系统的开放性得到保证，面向对象技术的应用不但提高了系统的通用性和可复用性，而且简化了作用分值的计算过程，提高了计算效率。该模型应用于“宗地评估与地价查询系统”的研究开发和实践，优越性显著。

Object-Oriented Feature-Based Model for Land Classification

An object oriented model of land classification based on feature, which includes feature object model, feature dictionary model, functional value computing model and distributed database model, was put forward and discussed. The feature objects encapsulate the geometrical and non geometrical information of the factors for land classification and realize the data integration, which make it easier to maintain the consistence of the classifying data. The model takes all the benefits from the object oriented modeling method. The consistence of the two parts can be guaranteed by a mechanism called transaction management. The data attached to the specified land being stored in the same database space of the land map prevents the two parts of data apart physically, which makes the data more safety. The object oriented feature based model for land classification mentioned in this paper was successfully applied to the development of a land appraisal and inquiry system. Its facility and speediness to modeling the specified land and its efficiency of calculating were tested.