面向对象的河口滩涂冲淤变化遥感分析

河口滩涂位于江河入海口前沿，其岸线受江河上游来水来沙、海水潮汐动力和人为因素影响处于不断变化中。针对遥感人工目视解译判读出岸线进行冲淤变化分析方法的不足，提出了面向对象的岸线遥感识别提取方法，阐述了整个遥感迭代识别提取过程。以长江河口崇明东滩为实验区，选取长江口1990年12月4日、1995年4月6日、2000年6月14日和2005年11月27日4个时相的陆地卫星TM/ETM+遥感影像，对其进行基于面向对象的识别处理，直接提取相应年份的岸线和滩涂陆域多边形，对4个年份的陆域多边形进行空间叠加分析，得到了崇明东滩自1990年以来15年间的冲淤空间变化。应用表明面向对象的遥感分析识别技术在河口滩涂冲淤变化分析中具有准确、快速、简便的特点。

OBJECT-ORIENTED IMAGE ANALYSIS METHOD FOR ESTUARINE TIDAL FLAT ACCRETION AND EROSION STUDY

The shorelines of tidal flat in an estuary,located in the intersection zone of river and sea and in- fluenced by run-off water together with sediments from upstream,wave and current,tidal dynamics and hu- man activities,vary continuously in time and space.In overcoming some shortcomings existing in visual in- terpretation of shoreline from remote sensing images,this article elaborates an object-oriented shoreline au- tomatic extraction method.Taking east tidal flat region of Chongming Island(Dongtan)as an experimental area,four scenes of TM/ETM images acquired respectively on Dec 4 1990,April 4 1995,June 14 2000 and Nov 27 2005 covering Chongmin Dongtan are processed based on the object-oriented method.The shore- lines and polygons representing the tidal flat above shorelines are extracted for each year.The overlay anal- ysis is applied to observe the spatial variation of erosion and accretion of Chongming Dongtan from 1990 to 2005.The application results prove that the object-oriented remote sensing image recognition method for shorelines and tidal flat erosion and accretion analysis is quick,easy to use and effective.