Study On The Forest Sub-compartment Map Updating Technology With SPOT Imagery

Not only is forest a key component of national nature resource, but also is the physical foundation we live by, and it plays a critical role in national economic development. Through forest inventory, forest quantity and quality data can be obtained timely to support a nation, region, or organization with accurate base information in making forest policies, preparing forest division and management plans, and guiding forest productions. Forest inventory has become an essential work for forestry.Forest Management Inventory (Category II Inventory) is a major part of forest inventory. One of its key outcomes is the forest sub-compartment map, the base map guiding the forestry production and the graphic document most widely used in forestry operation management. Since Forest Management Inventory is performed every ten years, updating of the forest sub-compartment map become an important part of it. Most of the traditional updating methods are done manually, and their effectiveness and accuracy cannot satisfy the requirements of forest inventory administrative department as well as the forest management works. The development of satellite technology has provided the updating of forest sub-compartment map with new technology and instruments.As such, on the base of the researching of current development status of forest monitoring and management in developed countries, this paper focuses on the study of updating technology of forest sub-compartment maps, and mainly resolved the key technical issues and problems in forest monitoring with remote sensing. This is of great importance in promotion and improvement of the information and modernization in forest monitoring and management. On business process level, this paper proposed a process flow for the updating of forest sub-compartment map with SPOT 5 satellite data; on technical level, this paper studied the enabling technology in updating of forest sub-compartment map: the forest polygon information extraction technology, and constructed a efficient classification model for the updating of forest sub-compartment map; on the application level, this paper proposed standards and technical specifications for forest databases, packaged all the processes, studied and developed a well performed forest sub-compartment map updating support system which is fairly complete functionally.The main contents of this paper include:①Study how to follow the forest management inventory specifications and design a streamlined forest sub-compartment updating business process using SPOT5 imagery that seamlessly integrates the various technology processes in imagery pre-processing, processing, forest land information extraction, updating of sub-compartment data, and production of forest sub-compartment map;②Study how to utilize forest compartment border lines, mountain ridge lines, and other types of forest specific data in enhancing the SPOT imagery quality, to speed up the processing time and improve the classification efficiency while maintaining the accuracy;③Study how to integrate satellite imagery fast correction and fusing technologies, forest classification technology, sub-compartment border extraction technology, and forestry monographic map production technology to construct an efficient and effective forest sub-compartment updating support system using object oriented design philosophy and component based design principals;The major contributions of this paper include:④Addressing the lack of streamlined forest sub-compartment map updating business process issue, this paper proposes the first streamlined forest sub-compartment updating business process using SPOT 5 satellite imagery. This process seamlessly integrates business, technical and quality control processes and fills in the blanks in this field. It has been successfully applied it to the real-world business and is well acknowledged;⑤Addressing the issues of heavy manual involvements, long process time, and low accuracy issues in current forest classification modules, this paper proposes a hybrid classification model for updating of forest sub-compartment map that integrates supervised an unsupervised classification models. The model starts by partitioning the SPOT 5 imagery using forest borders, mountain ridges lines to avoid the calculation on whole SPOT 5 imagery and in turn to reduce the data to be processed. Then the model uses unsupervised classification to determine the categories of the pixels and aggregate them to form forest polygons. The aggregated polygons are then classified with expert inputs using supervised classification algorithms. This avoids the supervised classification on pixel level and thus reduces the involvements of experts without sacrificing the classification accuracy. Based on experimental comparison, this new hybrid model greatly improves the efficiency and accuracy of the classification, and clears one of the key issues in advance manual updating of forest sub-compartment map to computer aided updating;⑥Addressing the issue of lack of practical and industrialized forest sub-compartment map updating system, based on in-depth study of the business process and technical issues in this field, an effective and efficient computer aided forest sub-compartment map updating system has been designed and developed which seamlessly integrates various data processing, classification, and analysis models. The system can facilitate the transformation of forest sub-compartment map updating from manual to semi-automatic and in turn make it possible to greatly improve the updating efficiency.