Fuzziness of spatial data is one of the difficult issues of current GIS research fields

However

existing GIS data model basically does not have the ability of describing

processing and analyzing the fuzziness of spatial data

which is very easy to make information loss in data processing. Fuzzy objects are defined to describe fuzziness of geographical phenomena and processes. Every element of an object does not always belong to one object

but can belong to several fuzzy objects with a fuzzy number indicating degree it belongs to the object. In this article

we combine the advantages of rough set with that of fuzzy set to express fuzzy objects. First

giving arbitrary two real numbers α

β and letting 0< β≤α ≤1

then

a fuzzy object A can be described as combination of down approximation RA α and upper approximation RA β using rough set. Second the interior of A can be defined as RA α

its boundary as RA β-RA α

and its exterior as U RA β

U is the domain. Finally

the 9 interxection model of spatial topological relations proposed by Egenhofer can be extended by using the new definition of object’s interior

boundary and exterior

and the topological relations between two fuzzy regions

and between a fuzzy region and a fuzzy line under the extended model are researched. There are three types of region/region topological relations

such as fuzzy regions and fuzzy regions （FF）

fuzzy regions and crisp regions（FC）and crisp regions and crisp regions（CC）

and four types of line regions topological relations

such as fuzzy regions and fuzzy lines（FF）

fuzzy regions and crisp lines（FC）

crisp regions and fuzzy lines（CF）and crisp regions and crisp lines（CC）in the paper. In contrast to 9 intersection model

the number of region/region topological relations discerned by extended model is 26 and that of line/region is 38

which is much more than that of 9 intersection model can be discerned. Generally

unlike the 9 intersection

the extended model has following advantages a fuzzy:1) it is enabled to describe the fuzzy objects and crisp objects in a union framework

2)the conventional method of spatial relation describing topological relations is a special instance of it

3) it studies the topological relations of fuzzy objects in details

and 4) it makes spatial data model enable to model the sptial phenomena with fuzziness and enhances the ability and precision of spatial data modeling.