Investigation on Land Database Updating Based on High Resolution Airborne Images

China has the biggest population all over the world. The food is always a problem faced by Chinese government. Therefore, to protect the land, which can grow the grain on, from decreasing is very important. However, with the development of economy, great deal of lands have been occupied by the factories and urban building. Development will make the land less, the food demand from the land is not decreasing even increasing, how to balance the relations between development and increasing food demands is a controversial question. In China two measures were used to overcome the question, one is to increase the production per mu, the second is to protect the land from reducing. Monitoring the land changes and updating the existed land database is the base of the second ways. There exist many methods to update the land database. Field surveying is suitable to a small area, remote sensing -based method is suitable to the large scope. For a middle scope such as 1000-10000 square kilometers, field surveying is not economic; the resolution of TM or SPOT image is not enough to monitor the changes of land. Maybe airbornebased method is rather suitable. In this paper a method based on airborne was proposed to monitor the land changes and update the land database. According to the airborne image, there are two cases. One is that two period of time color airborne image have existed, the second is that one period of time image is black airborne image and another is color image. For different cases, the method has little difference. They are used in Yiwu city and was testified operable and useful to manage land effectively.