考虑湿地精细分类的全球海岸带土地利用/覆盖遥感分类系统

Remote Sensing Classification System of Land Use and Land Cover for Global Coastal Zone Considering Fine Classification of Wetlands

土地利用/覆盖分类是土地利用/覆盖数据建立和土地利用/覆盖变化研究的重要前提。针对全球海岸带土地利用/覆盖类型多样性显著但分类系统鲜有专论的研究现状,从全球海岸带区域的基本特征出发,重点参考《湿地公约》以及区域至全球尺度的湿地分类系统,严格遵循预先定义的分类依据以及分类原则,提出全球海岸带土地利用/覆盖遥感分类系统,包括6个一级类型,分别为耕地、植被、湿地、建设用地、裸地、永久性冰川雪地,20个二级类型和43个三级类型,比较系统且全面地涵盖了全球海岸带区域的土地利用/覆盖类型和湿地资源。该分类系统层次清晰且分类严格,综合考虑了宏观区域至全球尺度海岸带土地利用/覆盖分类及变化特征遥感监测研究所需,充分重视了全球沿海区域丰富多样的湿地资源,明确强调了全球高纬度地区苔原类型的归属及分类,合理兼顾了低、中、高不同时空分辨率卫星数据的优势,为建立多时相全球或代表性区域海岸带土地利用/覆盖变化数据集提供支持。

Land use and land cover （LULC） classification is the important foundation for research on global changes, while establishing a scientific LULC classification system is the fundamental question for research on LULC changes, which is in need of being solved at first. It can influence the expressive methods of classification results, determine the research purposes and application areas of classification product. The existing LULC classification systems on regional or global scales place emphasis on monitoring and research in land areas, while several coastal LULC classification systems on national scale show specific pertinence and teleonomy. It is lack of universality of LULC categories in the global coastal zone, especially in the classification of coastal wetlands. In view of the significant diversity of LULC categories and a lack of LULC classification systems in the global coastal zone, the main research works are as follows： a detailed overview of global coastal zone was presented; the Ramsar Convention was of particular concern, as were several wetland classification systems on regional or global scales; the classification rules and classification principles were defined and followed strictly. As a result of this study, we established one kind of LULC classification system for global coastal zone considering fine classification of wetlands. More specifically, this classification system, which covers most types of land resources comprehensively, includes six primary categories and 20 secondary categories as well as 43 tertiary categories. It is worth mentioning that primary categories mainly include cropland, vegetation, wetland, built-up area, bare area and permanent ice and snow; furthermore, tertiary categories emphasize the division of coastal wetland resources adequately and accurately, including coastal saltwater and inland freshwater, which hold a total of 16 basic categories. This classification system has clear hierarchy and strict classification, as compared with the traditional classification systems. The advantages of this system are as follows： 1） it meets the need of remote sensing monitoring research on LULC classifications and changes in coastal zones on regional or global scales; 2） it attaches importance to the rich and diverse wetland resources in the global coastal areas; 3） it emphasizes the attribution and classification of tundra in the high latitudes of the world; 4） it takes into account the advantages of low, medium and high spatial resolution satellite data. Overall, such a classification system can provide support for establishing the multi-temporal datasets of LULC changes in the global or regional coastal zones, which is not restricted by the source data types; it can also provide service for scientific research on coastal zones on different scales by adding and deleting categories, which is applicable to different researchers.