地理研究 ›› 2014, Vol. 33 ›› Issue (12): 2382-2392.doi: 10.11821/dlyj201412015

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江苏中部海岸互花米草扩展对滩涂围垦的响应

朱冬(), 高抒()   

  1. 南京大学海岸与海岛开发教育部重点实验室, 南京 210023
  • 收稿日期:2014-06-21 修回日期:2014-10-13 出版日期:2014-12-10 发布日期:2015-03-13
  • 作者简介:

    作者简介:朱冬(1989- ),男,安徽固镇人,硕士,主要从事海洋地质学、海岸地貌学和沉积学研究。E-mail:zhudonglw@126.com

  • 基金资助:
    江苏省自然科学基金项目(BK2011012)

The expansion of Spartina alterniflora marsh in response to tidal flat reclamation, central Jiangsu coast, eastern China

Dong ZHU(), Shu GAO()   

  1. Key Laboratory of Ministry of Education for Coast and Island Development,Nanjing University, Nanjing 210023, China
  • Received:2014-06-21 Revised:2014-10-13 Online:2014-12-10 Published:2015-03-13

摘要:

根据2001-2013年遥感影像和野外观测数据,对江苏中部海岸互花米草(Spartina alterniflora Loisel)在滩涂围垦期间的扩展过程进行定量化分析。结果显示:2001-2013年互花米草扩展对围垦的响应大体分为三个阶段:2001-2007年,海堤外米草面积较大,每年新增米草面积及米草年扩展率均和新增围垦面积变化同步,且相关性显著;2008-2010年,海堤外米草面积较小,但米草年扩展率仍然较高;2011-2013年,随着围垦的持续进行,米草扩展进入稳定期。因此,互花米草扩展对于滩涂围垦的不同速率和阶段具有不同的响应。若围垦时保留足够宽度的堤前米草,则围垦可以提高米草的年扩展率,其机理是互花米草种子产量和前缘淤积环境是影响米草扩展的主要因素,而围垦对这两方面都有影响。在后期滩涂围垦时,应保证堤外米草宽度在0.9~1 km之间,实现土地资源的可持续利用。

关键词: 互花米草盐沼, 滩涂围垦, 遥感分析, 沉积动力过程, 江苏海岸

Abstract:

The central Jiangsu coast is typical of China's coastal muddy silt with an average tidal range of 4 m. The shoreline has been gradually advancing seaward as the coast was supplied by a large amount sediment from ancient Yangtze River and Yellow River. As a result, a lot of land resources are fostered in the coast. Therefore tidal flat reclamation activities gradually intensified to the demand of economic development. A large-scale reclamation plan in Jiangsu coast has been implemented since the 21st century and Spartina alterniflora marsh has become the main target of tidal flat reclamation. Thus how Spartina alterniflora marsh will expand during the reclamation period is worthy of study. Thirteen phases of satellite imageries from 2001 to 2013 and field observation data are analyzed to quantify the expansion rate of Spartina alterniflora marsh in association with the reclamation activities. The result shows that Spartina alterniflora expansion during 2001-2013 can be divided into three periods. During 2001-2007, the Spartina alterniflora area outside the seawall was relatively large and the influence on the tidal flat sedimentary environment by reclamation did not hamper its expansion. As a result, both the annually increased Spartina alterniflora area and the expansion rate keep pace with reclamation. During 2008-2010, the Spartina alterniflora area outside the seawall decreased significantly; nevertheless, the mean annual expansion rate of the Spartina alterniflora marsh was still relatively high. During 2011-2013, the area of Spartina alterniflora marsh became small because of the reclamation activities during 2001-2007 and 2008-2010 periods. Spartina alterniflora expansion became stabilized. As such, the pattern of the marsh expansion differs in response to the reclamation rate and stages. If a sufficiently wide marsh can be maintained during reclamation, then the marsh will continue to grow. The underlying mechanism is that the Spartina alterniflora marsh is influenced by the generation of seedling and the sediment types and bed elevation, while reclamation will affect all these factors. The relationship between marsh expansion and reclamation rate for the period of 2001-2007 indicates that, for sustainable reclamation on the Jiangsu coast, a width of 0.9-1 km for the Spartina alterniflora marsh should be maintained.

Key words: Spartina alterniflora marsh, reclamation activities, remote sensing analysis, sediment dynamic conditions, Jiangsu coast