获得不同时期的海岸线信息是海岸带管理的基础工作，海岸线信息的提取与海岸线变化的监测对海岸资源管理、海岸环境保护、海岸可持续发展以及合理规划起到至关重要的作用。本文旨在分析改革开放以来的中国大陆海岸线与海岸工程的时空变化特征。利用Landsat MSS、TM、ETM+和OLI多时相遥感影像，提取了1980年、1990年、2000年、2010年和2015年共5期中国大陆海岸线。综合运用遥感与GIS技术，从海岸线类型分布特征、长度、形态、空间变迁等方面系统分析了近35年中国大陆海岸线的时空变化规律。改进区域海岸线开发利用负荷度指数，结合海岸线类型变化、岸线摆动区域土地利用变化，对近35年中国大陆海岸开发利用状况进行系统分析。然后在对沿海地区养殖用海、盐田用海和港口码头时空变化分析的基础上，利用社会经济统计数据并结合典型区分析海岸线变迁的成因。主要结论如下：
    (1)1980-2015年，中国大陆海岸线长度持续增加，变化强度逐渐增大。海岸线类型转化频繁，人工岸线剧增，自然岸线锐减。(2)中国大陆海岸线的变迁呈现显著的时空差异。从时间过程看，2000年以后海岸线长度进入快速增长时期；从区域范围看，辽东湾北部、渤海湾-黄河口-莱州湾南岸、江苏南部-长江口-杭州湾南岸、珠江口岸段海岸线的变迁最显著。(3)海岸线分形维数逐渐增大，岸线形状趋于复杂，其变化趋势与海岸线长度变化一致。(4)中国大陆海岸线整体向海推进，人为海岸开发修筑的海岸工程是导致岸线变化的主导因素。(5)中国大陆海岸线多为未开发岸线，其次为重度开发岸线。自1990年以来，中国大陆岸线开发利用负荷度逐渐升高。区域性差异显著，以杭州湾为界，以北区域的海岸开发利用负荷度高于南方。(6)1980-2015年，养殖用海、盐田用海和港口码头的变化呈现显著时间差异。2000年之前海岸开发以围垦养殖、盐田为主；2000年之后，港口码头进入高速发展的阶段，同时存在一定的盲目性和建设超前的问题。
        论文创新点：1）基于全国尺度和长时间序列的海岸线类型信息提取及岸线变迁分析。
2）改进区域海岸线开发利用负荷度指数，结合海岸线类型变化、岸线摆动区域土地利用变化，对近35年中国大陆海岸线资源的开发利用状况进行系统分析。3）从单一海岸工程角度，结合社会经济数据，分析海岸开发时空变化特征及其对海岸线变化的影响。
 

      For coastal zone monitoring, coastline extraction in various times is a fundamental work. Coastline mapping and coastline change detection become critical to coastal resource management, coastal environment protection, sustainable coastal development, and planning. This paper focuses mainly on spatial-temporal variation of china mainland coastline and coastal engineering since China’s Reform and Opening. In this study, these changes were examined by using satellite images (Landsat MSS, TM, ETM+ and OLI) from collected between 1980 and 2015. This paper retrieved categorical mainland coastline information in mainland China in the year of 1980, 1990, 2000, 2010 and 2015. The spatial-temporal variation of China mainland coastline was analyzed systematically in the aspects of the spatial distribution of coastal types, length changes, changes in shape and spatial change utilizing Remote Sensing and GIS technologies. The utilization of China mainland coastline was analyzed systematically in the aspects of improved utilization intensity, coastline type change and land use change over the past 35 years. Then the spatial-temporal characteristics of coastal engeering of aquaculture pond, salt field and seaport and its impact on the coastline changes were analyzed combined with social-economic data and typical area. The main conclusions were as follows:
      (1)During the research period, the length of China’s mainland coastline increased continuously and the rising intensity cincreased progressively. The types of coastline changed significantly. The amount of artificial coastlines increased continuously and dramatically, while the length of the natural coastlines decreased acutely. (2) The variation of China mainland coastlines showed notable temporal and spatial heterogeneity. The coastline length entered a period of rapid growth after 2000. Areas that had coastlines that changed significantly were concentrated in Bohai Bay, the south and west bank of Laizhou Bay, the north bank of Liaodong Bay, the south of Jiangsu Province, Yangtze River Delta, the south bank of Hangzhou Bay and Pearl River Delta. (3)The fractal dimension of the overall coastline was increased steadily, whose change trend was consistent with the length of the coastline, indicating that the geometry of the coastline of the study area became more complex. (4)The coastline mainly expanded seaward and coastal engineering construction were the leading factor in coastal evolution. (5)The unutilized coastlines and heavily utilized coastlines are the major components of China mainland coastline. After 1990, the utilization intensity of mainland coastlines showed an increasing trend. The dividing line of the regional utilization intensity was in the Hangzhou bay, the regional utilization intensity of the northern coastlines were higher than the shouther coastal area. (6) The variation of reclamation of aquaculture pond, salt field and seaport showed significant temporal heterogeneity. Before 2000, coastal development was predominantly constituted by reclamation of aquaculture pond, salt fields; while after 2000, the seaports had entered a stage of rapid development with the problems of a certain blindness and constructing in advance.
      The innovation points: 1) This paper retrieved categorical mainland coastline information and analyzed its spatial-temporal variation based on the national scale long term series. 2) The utilization of China mainland coastline was analyzed systematically in the aspects of improved utilization intensity, coastline type change and land use change over the past 35 years. 3) The spatial-temporal characteristics of coastal development and its impact on the coastline changes were analyzed in the aspects of single coastal engineering, combined with social and economic data.