Abstract: A new method for expressing and reasoning directional relations between indeterminate spatial regions based on the operation property of interval value is given after analyzing existing models which is different from the original directional relation models that use traditional fuzzy set and cutset. The membership grade of direction relations between indeterminate regions is analyzed via interval value direction relation matrix. We divided directional relations between indeterminate regions into four types: directional relations between crisp regions, directional relations between crisp region and indeterminate region, directional relations between indeterminate region and crisp region and directional relations between indeterminate regions. The model can uniformly deal with crisp regions as a specific case of indeterminate regions. It is valuable in the fields such as GIS, spatial reasoning.

Key words: direction relations, indeterminate regions, spatial reasoning