主要研究基于自然语言 (汉语 )的GIS路径重建问题 ,通过分析带有路径表述信息的汉语文本 ,建立了汉语的NLRP句法模型 ,它是由带有空间语义的动作以及作为动作对象的地理要素构成的集合。考虑到自然语言理解实现的需求 ,论文基于NLRP句法模型定义了受限汉语的NLRP文法 ,在此基础上 ,描述了路径重建算法PRA ,并探讨了算法实现中由于空间认知原因带来的不确定性问题以及其解决方案。最后 ,基于该算法进行了相关实例研究 ,从而验证了该算法的正确性

It is well-known that natural language usually can provide much more precise and convenient spatial information in the context of social geographical information service.This paper researches the method of the GIS path reconatruction based on natural language(Chinese)containing geo-spatial information,which is called as natural language representation of path (NLRP). Through analyzing Chinese sentences that contain path representation,a syntax madel of NLRP for Chinese is built,which mainy contains a set of actions with spatial constraint and action objects.As a rule,the action objects usually are geospatial features.Considering the contribution to the forming of a concrete path, the actions in NLRP can be classified into three types:durative actions,transitional actions and parallel actions.Durative actions can last for a period of time,and each of them forms one segment of the whole path;transitional actions change the atate of the activities,such as“turn left”，and it occurs inside another durative action both spatially and tempoerally,such as“pass by”.Generally speaking,durative actions are corresponding to linear features and time segments,while a non-durative action,can be mapped to a specific event point in spatial and temporal space.In the model,the actions with spatial semantics can be sefined precisely using 9-I matrix. According to the model above,the NLRP syntax for constrained Chinese language is defined using BNF.Then the path reconstruction algorithm(PRA)and two interrelated issues,i.e.dictionary design and software architecture design,are discussed.In PRA,using interemediate result of the syntax processing,which is a sequence of actions,the action series are analyzed and the spatial relationships between objective path and related features are examined based on the geographical reference map.At last,the concrete path can be figured out. Furthermore,a NLRP expression contains some uncertainties inevitably,which may come from the spatial cognition process and imprecise expression.The uncertatinties of NLRP bring ambiguities to PRA,and increase the algorithm complexity.They include uncertainties of direction,uncertainties of distance and uncertanties of topologic relationship.Meanchile,solution to them is also discussed,the essential of which is to distinguish major flag and minor flag of a durative action,and the former determines the shape of path,while the latter may be used to check errors of an NLRP description. Finally,a case study of PRA is described to validate it.