地球信息科学学报 ›› 2019, Vol. 21 ›› Issue (2): 269-278.doi: 10.12082/dqxxkx.2019.180344

• 遥感科学与应用技术 • 上一篇    下一篇

长江三角洲滩涂信息的遥感提取及时空变化

仇传银(), 李行*(), 刘淑安, 陈丹   

  1. 江苏师范大学地理测绘与城乡规划学院,徐州 221116
  • 收稿日期:2018-07-27 修回日期:2018-11-29 出版日期:2019-02-20 发布日期:2019-01-30
  • 通讯作者: 李行 E-mail:qiucy2012@163.com;lixing@jsnu.edu.cn
  • 作者简介:

    作者简介:仇传银(1993-),男,山东淄博人,硕士生,主要从事海岸带湿地遥感应用研究。E-mail: qiucy2012@163.com

  • 基金资助:
    国家自然科学基金项目(41401093)

Monitoring Tidal Flats in the Yangtze River Delta Using Landsat Images

Chuanyin QIU(), Xing LI*(), Shu'an LIU, Dan CHEN   

  1. School of Geography, Geomatics and Planning, Jiangsu Normal University, Xuzhou 221116, China
  • Received:2018-07-27 Revised:2018-11-29 Online:2019-02-20 Published:2019-01-30
  • Contact: Xing LI E-mail:qiucy2012@163.com;lixing@jsnu.edu.cn
  • Supported by:
    National Natural Science Foundation of China, No.41401093

摘要:

海岸带滩涂是重要的生态资源,对于环境保护和区域可持续发展具有重要意义,是学术界研究的热点区域。但由于滩涂周期性地被潮水淹没,通达性较差,传统的测量方式难以满足这一高度动态环境的变化监测需求,因此遥感观测方式成为一个潜在的选择。但遥感观测受成像方式、大气条件和潮情的影响,其应用仍面临很大的挑战。本文以苏北至上海南汇边滩沿岸作为研究区域,首先选择了1975年以来每年潮位最低的Landsat影像数据作为数据源,利用水边线作为滩涂的外边界,植被线或围垦大堤作为内边界提取滩涂面积;然后利用ArcGIS软件对获取的滩涂数据进行分析,以此来研究长江口滩涂的时空变化特征。结果表明:① 1975年以来研究区域滩涂面积整体上呈降低趋势;1990s之前滩涂面积基本保持稳定,1990s之后降低趋势较为明显;1995年前后研究区圆陀角以北的江苏海岸和以南的长江河口区域滩涂面积达到最大值,分别为1101.2 km2、1495.5 km2,至2017年,二者面积分别降为649.5 km2、1043.4 km2,1990年至今总体降低速率为21.7 km2/a;② 流域来沙减少和围垦、深水航道等河口工程是长江口滩涂面积减少的主要控制因素。

关键词: 长江三角洲, 滩涂, 遥感, 动态监测, 围垦, 控制因素

Abstract:

As an important ecological resource in coastal zones, tidal flats are of great significance for environmental protection and regional sustainable development. Additionally, tidal flats are sentinels of regional and global changes and thus have recently become a focus of academic research. However, the accessibility of tidal flats is poor because tidal waters periodically inundate them. This makes it difficult to employ traditional measurements to monitor such highly dynamic environments. Accordingly, remote sensing observation has become a potential choice. Yet, remote sensing observations also face great challenges because of influences from imaging modes, atmospheric conditions, and tide conditions. For this research, we selected the Yangtze River Delta, which is covered by a single full scene of Landsat image, as the study region, specifically including parts of the Jiangsu coast and the Yangtze River estuary zone. A collection of the Landsat images with the lowest tidal level in each year from 1975 to 2017 was selected as the main data sources. Meanwhile, to extract tidal flat data, we choose the waterline as the outer boundary and the vegetation line or reclamation dyke as the inner boundary. Then, ArcGIS software was used to acquire and analyze the temporal and spatial variability of the tidal flat data. The results show the following: (1) The tidal flat area in the study region has generally decreased since 1975. The area remained generally stable before 1990s, but after 1990s, the decline was evident. The tidal flat areas along the north of the Yuantuojiao Point and the Yangtze River estuary zone reached their maximums around 1995, at 1101.2 km2 and 1495.5 km2, respectively, but were 649.5 km2 and 1043.4 km2 by 2017. This indicates an overall decreasing rate of 21.7 km2/a. (2) Reduced riverine sediment, reclamation, and estuarine engineering projects, such as the Deep-water Navigation Channel project, are the main controlling factors in tidal flat shrinkage in the study region. The results provide a holistic perspective on the evolution of the tidal flats in the Yangtze River Delta, which may be helpful for coastal zone management and planning.

Key words: The Yangtze River Delta, tidal flat, remote sensing, dynamics monitoring, reclamation, controlling factor