The main problem of visual query languages for geographical data concerns query ambiguity. A query can have different visual representations, which in turn can have different interpretations. Increasing the number of query objects increases its ambiguity. This derives from the fact that a query can lead to multiple interpretations for both the system and user. The user's actions may not represent his intentions, leading the system to an incorrect interpretation. So the user cannot express his exact query and different queries must thus be formulated to achieve his goals. This paper proposes an approach that allows the user to represent only desired constraints and avoid undesired constraints in visual query representation.