厦门岛及其邻域海岸线变化的遥感动态监测

Dynamic Monitoring of the Shoreline Changes in Xiamen Island with Its Surrounding Areas of SE China Using Remote Sensing Technology

利用美国Landsat TM/ETM+卫星影像,分1989、1995和2000年3个时相,研究了福建省厦门市从1989～2000年的岸线变化情况.岸线变化的信息主要通过变化检测和信息提取等一系列遥感技术来获得.研究结果表明,厦门市在所研究的1989～2000年期间,海域面积共减少了7.54 km2,这主要是由于城市用地扩展和养殖业发展占用了海域的面积.分时段研究表明,从1995～2000年,海域减少的面积明显要比1989～1995年期间来的多,这从一个侧面反映了厦门在1995～2000年间,城市建设和经济发展对土地提出了更高的需求.

The shoreline changes in Xiamen Island with its surrounding areas of SE China from 1989 to 2000 have been detected using remotely sensed data. Three Landsat TM/ETM＋ images of 1989, 1995 and 2000 have been used for this study. The MNDWI （Modified Normalized Difference Water Index） with appropriate thresholds were used to extract the water information from the original images. However, the highlighted water also contains some information about inland waters, such as reservoirs, lakes and so on,which are unwanted in this study. Therefore, those inland waters should be further masked out from the MNDWI images. As a technique of change detection, the Red Green Difference Image is employed to reveal the shoreline changes and the changed area was thus calculated. The final results indicate that the sea area of Xiamen has been reduced by 7. 54km^2 during the study years. This was largely due to the rapid expansion of urban and fishing pools. Furthermore, the speed of the reduction has been speeded up in the last five years from 1995 to 2000. It reflected the urgent land demand of the urban construction and economy development in Xiamen during the years of 1995～2000.