龙口市20年间海岸带变化的遥感监测

Remote Sensing Dynamic Monitoring on Changes of the Costal Zone in Longkou City During 1984～2004

利用龙口市20年(1984～2004)来的12个时相的遥感图像,采用数字图像处理技术和目视解译方法提取了不同年代的海岸线、高潮线和低潮线。通过与基准线和人为因素的对比分析,研究海岸带的时空变化规律,及影响海岸带时空变化的主导因素。研究结果表明,龙口市海岸带总体变化趋势是:除人工海岸外,海岸带趋于向陆地移动,岸滩变窄、变低,潮间带变宽、坡度变缓,防潮能力下降;人类活动是导致海岸带时空演变的最根本因素,包括沿海基础设施的建设、农业结构的调整、采砂业的无序发展。其次是自然因素,包括沿岸流侵蚀与堆积以及海水入侵等。

The coastal zone is the belt influenced from land and ocean interactions, as well as human factors. So its evolution depends not only on natural factors but also on human socio-economic activities. It has very good instructive meaning to provide timely accurate coastal zone changes information for exploiting and protecting the coast and studying its ecological footprint. Using 12 periods remote sensing images covering 20 years from 1984 to 2004 of Longkou city, this paper extracted the coastline, the high tidal line and the low tidal line from different years utilizing different methods and techniques of data image processing and visual interpretation based on the characteristic of each RS image and checked up the extracted tide information with the tide data from two tide monitoring stations. On the basis of contrasting with the base line, the paper analyzed the law of the costal zone changes in both spatial and temporal aspects, and then discussed the major influential factor to the changes by analyzing natural and artificial factors. The results indicated that in addition to the artificial seashore, the general trend of the coastal zone evolution in the 20 years was moving to sea during the former 10 years and moving to land during the latter 10 years, and the changing extent was on the increase year after year. The protection against the tide came down by reason of the bank turning narrow and low, the tideland turning broad, and the gradient turning gentle. It was clear that human activity had great impacts directly and indirectly on the costal zone evolution. The most fundamental activities included infrastructure construction in the nearshore zone, the adjustment of the agricultural structure, industry. The natural factors had been also found affecting deposition, sea-water intrusion, etc. and the unordered development of the sand dredging the evolution of the zone, such as shore cutting and