基于MSS/TM/ETM图像的长江马芜铜段江心洲演化研究

长江下游马芜铜段河床中,堆积式江心洲大量存在且演化迅速。选取具有代表性的8个江心洲,利用1979、1989、2001、2006和2009年5期MSS/TM/ETM遥感数据,结合野外辐射光谱仪测定的江心洲典型地物光谱曲线,选择合适波段组合,经过几何校正、图像裁减、二值化处理、图像卷积运算、图像聚类统计等步骤获取8个江心洲时空演化信息。研究表明：① TM遥感数据能够实现对江心洲信息的快速准确提取;② 长江下游马芜铜段江心洲在1979~2009年以扩张为主,但各江心洲的扩张速率在各时段差异较大,可能与上游地区来水来沙量、人类活动等有密切关系;③江心洲的演变受自然因素和人为因素的共同影响,自然因素直接导致江心洲淤积或缩小,而人为因素主要改变江心洲形成的外源物质条件等。

Study on Channel Islands in Ma-wu-tong Section of Yangtze River based on MSS/TM/ETM Remote Sensing Image

There are many accumulation river islands in Ma-wu-tong Section of the Yangtze river,and the area of river islands change rapidly.We chose eight river islands and studied their changes on TM(Thematic Map),and the dates of MSS/TM/ETM are 1979,1989,2001,2006 and 2009.We determined the spectrum of typical objects in river islands by ISI921VF-256T Field Spectroradiometer,combined the right bands,and interpreted the images by geometric correction,subset images,binarization processing,convolution and clump.The results show that:① TM remote sensing data can be used to achieve change information of river islands quickly and accurately;② The eight river islands extended continually during the past 30 years,and the extended speed was not averagely,which might be resulted from reducing water or decreasing the sediment-carrying capacity;③ Evolution of river islands are controlled by natural factors and human factors.A direct result of natural factors is ablation or siltation of river islands,and human factors change would result in the change of external substances,which is composition of river islands.