1990—2020年中国大陆泥质岸线的变化分析

Muddy Shoreline Change along the Coast of China's Mainland from 1990 to 2020

本研究基于Landsat TM、ETM+和OLI卫星影像数据,采用精细化标准,精确识别并分析了1990年至2020年间中国大陆泥质岸线的时空演变。通过运用最近距离法(NDM)和数字岸线分析系统(DSAS),本研究不仅揭示了泥质岸线的类型变化,还深入探讨了其空间分布的动态趋势。结果表明:1990年至2020年间,泥质岸线呈现显著减少的趋势,减少速度先快后慢。其中,2000-2010年间减少幅度最大,共计减少了367.82 km;泥质岸线向其他自然岸线的转变比例较低,而转变为人工岸线(尤其以养殖围堤为主)的比例较高,这反映了人类活动对泥质岸线变化的重要影响;泥质岸线主要呈现向海推进的趋势,这种变化由南向北逐渐增强。然而,部分岸段出现了侵蚀现象,表明局部地区可能面临岸线退化的风险;泥质岸线的变化速率在2000-2010年间达到最大,随后逐渐放缓。这种速率的变化反映了泥质岸线在不同阶段受到不同因素的影响。泥质岸线的变化不仅包含增加和减少两个过程,其保护对于维护海洋生态平衡、保障沿海地区可持续发展具有重要意义。此外,泥质岸线的保护还能为其他自然岸线的保护提供有力支持。

This study,based on Landsat TM,ETM Plus,and OLI satellite imagery data,employs a fine-scale standard to precisely identify and analyze the temporal and spatial evolution of muddy coastlines on the mainland of China from 1990 to 2020.By using the nearest distance method(NDM)and digital shoreline analysis system(DSAS),this study not only reveals the change in the type of muddy coastlines but also deeply explores the dynamic trend of their spatial distribution.The results show that from 1990 to 2020,the muddy coastline has shown a significant decreasing trend,with the decreasing speed first fast and then slow.Among them,the reduction from 2000 to 2010 was the largest,a total of 367.82 km reduced;the proportion of transformation into other natural coastlines is lower,while the proportion of transformation into artificial coastlines(especially aquaculture dykes)is higher,which reflects the important influence of human activities on the change of muddy coastlines;the muddy coastline mainly shows a trend of advancing towards the sea,and this change gradually intensifies from south to north.However,some sections have shown erosion,indicating that some local areas may face the risk of coastal degradation;the rate of change of muddy coastlines reaches its maximum from 2000 to 2010 and then gradually slows down.The change in the rate of change reflects the different influences of muddy coastlines in different stages.The changes in muddy shorelines not only involve the processes of increase and decrease,but their protection is of great significance for maintaining the ecological balance of the marine environment and ensuring the sustainable development of coastal areas.Moreover,the protection of muddy shorelines can also provide strong support for the protection of other natural shorelines.