基于潮位校正的盐城滨海潮间带遥感监测及变化分析

潮间带是重要的滨海湿地类型之一,在生物多样性保护、全球环境变化等方面具有不可估量的价值。遥感技术已经成为滨海湿地监测的重要手段。针对潮间带遥感监测中存在时相限制的瓶颈问题,本文结合卫星过境时潮位信息,通过建立GIS模型,将利用遥感方法提取出的瞬时水边线校正至平均高、低潮线,改进了通过遥感数据恢复潮间带高程和范围的方法。在此基础上,利用1995年、2000年、2005年、2010年和2015年的多期Landsat TM以及OLI遥感数据,对盐城滨海潮间带进行了遥感监测和分析。结果表明:（1）2015年江苏盐城潮间带面积为809.27 km2,相比1995年减小了47%;（2）1995年以来盐城滨海潮间带面积总体呈减小了趋势,其中1995-2000年潮间带面积减小幅度最大,约为205.67 km2;（3）潮间带主要分布在盐城滨海南部晚庄港-新开港,占全部潮间带面积的66%;同时潮间带面积的减小也主要发生在这个区域,减小的潮间带面积占减小总面积的84%;（4）潮间带范围的变化受人为和自然双重因素影响;海平面上升和滨海湿地的大量围垦,造成了潮间带的挤压效应,使得潮间带面积迅速减小,湿地围垦等人为因素起到主导作用。

Remote-sensing analysis of Yancheng intertidal zones based on tidal correction

Intertidal zone is one of the most important coastal wetland types, which contains immeasurable value in biodiversity protection and global environmental changes. Remote-sensing technology has become an important tool for coastal wetland monitoring. However, there are still challenges to map intertidal zones due to the discrepancy between imagery acquisition time and the local time of the highest and lowest tide. Here, we improve the method of restoring ranges of intertidal zones by combining remote-sensing images and tide model with the aid of GIS. In this way, we using multi-temperal Landsat TM images in 1995, 2000, 2005 and 2010, and Landsat OLI images in 2015, Yancheng intertidal zones are successfully mapped. Results show that the area of Yancheng intertidal zones is about 809.27 km², decreased by 47% compared with 1995. And the area of intertidal zones, in fact, has been decreasing continually since 1995. The maximum area loss, about 205.67 km², happened during 1995 to 2000. What''s more, intertidal zones are mainly distributed in the south part of Yancheng coastal region, which accounts for 66% of the whole area. And the main loss happened here also, which accounts for 84% of the total area loss.Changes of intertidal zone range can be attributed to both natural and human factors: sea level rising moving the tidal flats toward to land, while intense coastal development moving high-tide lines toward to sea, finally result in "squeezing effects" of the intertidal zones, which ultimately lead to the loss of the study area.