Abstract: Data updating of forest resources is to ensure the data reflect the status quo of forest resources timely and accurately. Vectorization of changed sub-compartments is basic to updated forest resources data. The current vector tracking algorithms and software cannot operate the automatic sub-compartment vectorization through contour lines,as a result of huge intersecting between changing sub-compartments and contour lines during field inspection. Consequently,the workload of vectorization becomes heavier,and its accuracy and efficiency get lower as well. The vectorization proposed in this paper is based on mathematical morphology. It can make the automatic vectorization of sub-compartments through cross points come true and greatly improve the accuracy and efficiency of updating data collected.

Key words: forest resources, data updating, mathematical morphology, vectorization