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

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

Research on remote sensing mapping and change characteristics of land use/land cover in the global coastal area based on multi-source data fusion

近年来，世界各国及组织相继运用不同的遥感影像和分类技术，开展了大量以土地利用/覆盖为主体的遥感制图研究，形成了众多区域至全球尺度的土地利用/覆盖数据产品。但随着相关研究的不断深入，这些数据产品的不足和局限也逐渐突显，即：由于数据来源、分类体系和分类技术不同，这些数据产品存在数据精度不高、数据间一致性不足、与统计数据差异显著等诸多问题。鉴于此，在多源数据共存和融合研究兴起的背景下，开展基于多源数据融合的全球海岸带土地利用/覆盖遥感制图及变化特征研究对于反映海岸带环境变迁、揭示沿海生态系统演替、探究气候变化对海岸带的影响效应等具有重要意义。 本研究根据全球海岸带地域特点，界定全球海岸带地理范围，构建全球海岸带土地利用/覆盖遥感分类系统，分析多源土地利用/覆盖数据产品在全球海岸带的一致性，在此基础上，选取总体精度相对较高的三套土地利用/覆盖数据产品（MCD12Q1、CCI-LC和GlobeLand30）作为源数据集，采用一种基于一致性分析和模糊集合理论的数据融合方法，获取2000年和2010年全球海岸带土地利用/覆盖分类信息，揭示全球海岸带土地利用/覆盖变化特征及其驱动机制，进而结合GIMMS NDVI3g数据以及若干全球尺度湿地次级类型数据产品，开展全球海岸带植被覆盖变化特征及湿地潜在分布区遥感制图研究。主要结论如下： （1）全球海岸带范围界定：将向内陆延伸至海岸线以上一定范围的陆域和向海洋扩展到一定范围的海域界定为全球海岸带；其中陆域边界定义为海岸线向陆侧延伸100 km，海域边界取-100 m等深线和离岸10 km缓冲区的并集。 （2）全球海岸带土地利用/覆盖遥感分类系统确立：在详细评述区域至全球尺度土地利用/覆盖分类系统、海岸带土地利用/覆盖和湿地分类系统的基础上，提出适宜于全球海岸带的土地利用/覆盖遥感分类系统，有一级类型6个、二级类型20个和三级类型29个，共计43个基本类型。 （3）多源数据融合之前的数据源选择及可行性评价：多源数据产品对全球海岸带土地利用/覆盖构成的描述基本一致，但在细节上存在偏差；2000年各个数据产品组合的相关系数、总体精度和Kappa系数分别在0.8924~0.9974、69.54% ~80.18%和0.6005~0.7337之间，2010年分别在0.8814~0.9869、67.46%~81.50%和0.5748~0.7505之间；“两两”对比时草地、灌木地和湿地的混淆程度最高，耕地和人造地表次之，林地和未利用地较低，水体最低；“多源”对比时全球海岸带2000年有78.51%、2010年有88.64%的土地具有较高一致性。 （4）基于多源数据融合的全球海岸带土地利用/覆盖遥感制图及精度评价：相较于三套输入数据源，2000年融合数据集的总体精度、Kappa系数和平均总体一致性均是最高的，分别为86.48%、0.8097和82.83%，2010年亦均是最高的，分别为89.21%、0.8476和83.45%；2000年、2010年融合数据集中各个类型的生产者精度和用户精度均至少高于两套输入数据源的生产者精度和用户精度，且融合数据集中各个类型的平均一致性分别提高1.23%~29.37%和1.33%~33.13%。 （5）全球海岸带植被覆盖变化特征及其与土地覆盖之间的相关分析：荒漠带多为常年无植被和低植被覆盖区，苔原带多为中植被和较高植被覆盖区，林带多为高植被覆盖区；全球海岸带植被覆盖的年内变化表现为“∩”型曲线，年际变化呈现出波动但总体缓增的趋势；月季年多尺度全球海岸带植被覆盖增加区域分布最为广泛，降低区域面积相对较小；多数区域植被覆盖变化趋势在未来具有较强的正向持续性；在较高纬度的苔原带等生长季极为短暂的植被带，植被覆盖的增加趋势极为显著；沿海城市群和荒漠带周围的植被覆盖降低趋势亦较为显著。 （6）全球海岸带湿地潜在分布区遥感制图及精度评价：采用一种基于“类别置换”的数据集成方法，实现潮间滩涂、珊瑚礁、红树林、河流和沟渠、湖泊和坑塘、淡水沼泽、海草床等多套湿地次级类型数据产品的集成，集成结果精度评价显示：总体上制图结果的精度水平还不够理想、有待提升。 （7）全球海岸带土地利用/覆盖变化及驱动力分析：全球海岸带土地利用/覆盖变化以灌木地扩张和裸地萎缩为主，林地萎缩和永久性冰川雪地扩张次之，耕地收缩和草地收缩较少，湿地收缩和人造地表扩大最少；八个类型之间的相互转换面积较小，其中耕地–林地–草地相互转换、草地–灌木地相互转换、林地转为灌木地、湿地转为草地等占绝对优势；自然驱动力深刻影响着土地利用/覆盖变化的宏观格局，人文驱动力则是推动全球海岸带土地利用/覆盖变化的根本原因

Consistency of the Multiple Remote Sensing-based Land Use and Land Cover Classification Products in the Global Coastal Zones

Land Use and Land Cover (LULC) classification products play an indispensable role in ecosystem assessment, climate change simulation, national geographical condition monitoring, and macro-control policy analysis at the global scale; consistency analysis is the precondition of applying various LULC classification products. This paper assessed the area consistency and spatial consistency of five LULC classification products - MCD12Q1-2010, GlobCover2009, CCI-LC2010, FROM-GLC2010 and GlobeLand30-2010- in the global coastal zones. The five products were compared in terms of the deviation coefficient, correlation coefficient, error matrix, and spatial confusion of LULC types. The main findings are as follows: (1) The spatial patterns of LULC in five products demonstrate relatively strong overall consistency, but can have significant local inconsistency. (2) The five products are qualitatively consistent yet quantitatively inconsistent in classifying the LULC in the global coastal zones ? in terms of structure, water ranks top one, followed by forest and unused land, next are farmland, grassland and shrubland, and lastly wetland and artificial surface, yet the exact area of each LULC type differs among different products. (3) For the correlation coefficient, overall accuracy and Kappa coefficient, MCD12Q1-2010/GlobCover2009 have the minimum values, 0.8814, 67.46% and 0.5748, respectively; while GlobCover2009/CCI-LC2010 have the maximum values, 0.9869, 81.50% and 0.7505, respectively; it is because GlobCover2009 and CCI-LC2010 obtained from the same production organization have the same classification system, while MCD12Q1-2010 is different from GlobCover2009 in terms of the production organization, data source, classification system, and classification method. (4) For the spatial confusion/misclassification between any two different products, grassland, shrubland, and wetland have the highest mix-up ratios, followed by farmland and artificial surface, and lastly forest, unused land, and water; this difference is because forest, unused land, and water have distinctive spectral characteristics and clear spatial textures, while grassland, shrubland, and wetland have similar spectral characteristics and fuzzy spatial distributions. (5) There are 28.81% land area in the global coastal zones with relatively low consistency, i.e., with severe spatial confusion; specifically, the misclassification of farmland, forest, grassland, shrubland, wetland, and unused land has direct influence on the spatial consistency of the five products. This paper is hoped to serve as a reference of selecting data from the five available LULC products for researching coastal zones.</p

20世纪40年代初以来中国大陆沿海主要海湾形态变化

受气候变化和人类活动的影响,中国海岸带正在经历各种剧烈的变化,海湾形态变化是其中的一个重要方面。基于地形图资料与遥感影像提取20世纪40年代初至2014年7个时相的中国大陆沿海主要海湾的空间信息,进而分析海湾岸线类型结构、开发利用程度和空间位置的变化特征,以及海湾面积、形状和重心分布的变化特征。结果表明,20世纪40年代初以来,中国大陆沿海主要海湾的形态变化显著且复杂,主要体现为:海湾岸线的结构变化显著,自然岸线的长度和比例急剧减少;海湾岸线的开发利用程度持续增强;海湾岸线普遍背陆向海运动;海湾面积普遍大幅萎缩;海湾形状总体趋向复杂但个体间的差异在缩小;海湾重心分布位置普遍背陆向海迁移;海湾变..

Development trend,environmental and ecological impacts,and policy recommendations for Bohai Sea reclamation

In recent years,a new round of large-scale reclamation activities,driven by rapid industrialization and urbanization,has been carried out in the coastal areas of China. Bohai Sea,with a long history of extensive reclamation,has become the area with the most intensive reclamation activities in recent years. Owing to sea reclamation and estuarine delta growth,the area of Bohai Sea has shrunk by 0.57×10~4km~2 since the 1940s,with shrinking rates of >82km~2 /a and as high as 141km~2 /a since 2000. The natural coastline of Bohai Sea decreased sharply from 1397km in 1990 to 561km in 2014,and its proportion decreased from 54.92% to 16.18%. Large-scale reclamation might cause several hazards and decline of ecological functions,as well as ocean hydrodynamic changes,near-and off-shore topographical and morphological changes, coastal water and sediment pollution,tidal wetland damage,benthic habitat and community destruction,spawning and nursery ground degradation,natural disaster and social system risk aggravation in coastal areas,and declines in industry and economic development. Based on the analysis of the status quo and the problems of the management and policies for sea reclamation in China,the following policies were suggested: to reform and optimize the management system of the reclamation activities,to establish a land-sea coordination mechanism,to improve laws and regulations,to strictly execute the ecological red line system,to control the scale and speed of reclamation,to promote the construction of reserve area,to restore and reconstruct the ecological environment in the reclamation area,to strengthen the supervision and intensive use of the new land resources,to construct basic observation systems,to promote scientific research,and to promote the participation of the general public,stakeholders,and non-governmental organizations in conservation activities

20世纪40年代初以来中国大陆海岸线变化特征

基于多时相地图资料、遥感影像以及覆盖整个大陆海岸带的野外考察,建立20世纪40年代初以来6个时相的中国大陆海岸线数据,并从岸线结构、岸线分形、岸线变化速率、陆海格局和海湾面积等角度分析过去70年来中国大陆海岸线的变化特征.结论如下:大陆海岸线结构变化显著,岸线人工化是最主要的特征,目前自然岸线的保有比例已经不足1/3;大陆海岸线分维数具有"北方<整体<南方"的宏观格局特征,但近年来北方海岸带急剧的岸线人工化过程通过大大缩小岸线分维数的南北差异而显著改变了中国大陆海岸线的分形特征;大陆沿海的陆海格局与过程特征复杂,超过68%的海岸总体向海扩张,超过22%的海岸总体向陆后退,而净变化结果是陆地面积..

Shape changes of major gulfs along the mainland of Chinasince the early 1940s

受气候变化和人类活动的影响,中国海岸带正在经历各种剧烈的变化,海湾形态变化是其中的一个重要方面。基于地形图资料与遥感影像提取20世纪40年代初至2014年7个时相的中国大陆沿海主要海湾的空间信息,进而分析海湾岸线类型结构、开发利用程度和空间位置的变化特征,以及海湾面积、形状和重心分布的变化特征。结果表明,20世纪40年代初以来,中国大陆沿海主要海湾的形态变化显著且复杂,主要体现为:海湾岸线的结构变化显著,自然岸线的长度和比例急剧减少;海湾岸线的开发利用程度持续增强;海湾岸线普遍背陆向海运动;海湾面积普遍大幅萎缩;海湾形状总体趋向复杂但个体间的差异在缩小;海湾重心分布位置普遍背陆向海迁移;海湾变..

Shape changes of major gulfs along the mainland of Chinasince the early 1940s

基于多时相地图资料、遥感影像以及覆盖整个大陆海岸带的野外考察,建立20世纪40年代初以来6个时相的中国大陆海岸线数据,并从岸线结构、岸线分形、岸线变化速率、陆海格局和海湾面积等角度分析过去70年来中国大陆海岸线的变化特征.结论如下:大陆海岸线结构变化显著,岸线人工化是最主要的特征,目前自然岸线的保有比例已经不足1/3;大陆海岸线分维数具有"北方<整体<南方"的宏观格局特征,但近年来北方海岸带急剧的岸线人工化过程通过大大缩小岸线分维数的南北差异而显著改变了中国大陆海岸线的分形特征;大陆沿海的陆海格局与过程特征复杂,超过68%的海岸总体向海扩张,超过22%的海岸总体向陆后退,而净变化结果是陆地面积..