Abstract: The river classification is the key point and the technical difficulty for river expression in the map generalization, and the accuracy and calculation speed are higher requirements. In the previous research on river system classification, the algorithm's efficiency is low, and ring is without consideration in river system. Based on this, we set up the attribute rules, geometric rules and ring rules of river system classification to process different types of ring and use heuristic algorithm to realize the automatic classification of rivers system. The test results show that the river system containing rings can achieve good effect by this algorithm, and reduce the computation time.

Key words: map cartographic, river classification, river with a ring, heuristic algorithm