中国南方大陆海岸线时空变迁

海岸线变迁对于海岸带生态环境变化乃至全球变化研究具有重要意义。通过对5个时相TM影像的人机交互解译,获取1990年,1995年,2000年,2005年和2010年中国南方大陆海岸线信息,分析了各时段岸线变迁特征及变迁原因。结果表明:(1)中国南方大陆海岸线的长度和分形维度保持相对稳定,但岸线长度存在总体缩短和局部增长的演化趋势。(2)岸线海向推进的岸段占据主要部分,陆向缩退岸线仅发生在少部分岸段。(3)长江口—杭州湾南岸和珠江三角洲两个典型岸段的分析表明中国南方大陆岸线的时空变化速率与强度在不断加强。(4)在1990—2010年期间,引起中国南方大陆海岸线时空变迁的人为因素的作用比自然因素显著,并导致人工岸线比重不断增大,自然岸线比重不断下降。

Spatial-temporal changes of continental coastline in southern China

Coastline changes are of great significance in studying ecological environment changes in coastal zones and even all over the globe. Through human-computer interactive interpretation for the TM images of 5 time phases, 1990, 1995, 2000, 2005 and 2010, we acquired the information about southern China continental coastline, and analyzed the features and reasons of the coastline changes. The results show that: (1) The length and fractal dimension of southern China continental coastline remain relatively stable, but there exists the evolutionary trend of overall shortening and partly lengthening of the coastline; (2) The coastline advances seaward in main parts of the coast and backs landward only in a few parts of the coast; (3) Analyses on two typical coasts, Changjiang River estuary-south bank of Hangzhou Bay and the Pearl River Delta show that the rate and intensity of spatial-temporal changes in southern China continental coastline are continuing to strengthen; (4) In the period from 1990 to 2010, the spatial-temporal changes in southern China continental coastline caused by the human factors are more significant than thoses caused by the natural factors, resulting in the increasing of the proportion of artificial coastline, and declining of the proportion of natural coastline.