滩涂围垦对海滨湿地景观格局变化的影响研究

发布时间：2018-06-21 19:10

本文选题：围垦 + 海滨湿地　；参考：《南京师范大学》2015年硕士论文

【摘要】：海滨湿地是全球生物生产量最高的生态系统之一,是重要的环境资源,具有着极高的生态功能和巨大的公益价值。滩涂资源是海岸带最重要的自然资源之一,也是海滨湿地的重要组成部分。近些年,随着社会经济的发展和对土地的迫切需求,在高强度、高频率人类围垦活动干扰下,其景观格局发生着巨大变化,主要表现为天然湿地迅速转向人工湿地。为探讨滩涂围垦对海滨地区景观格局带来的影响,选取1973-2013年Landsat 1、4、5、7、8影像数据,利用GIS (Geographic Information System)、RS(Remote Sensing)和景观指数计算方法,以盐城国家级自然保护区(川东港—新洋港段)为例,分析滩涂围垦条件下,围垦区内部不同垦区景观变化特征,对比不同垦区在围垦前、围垦期间、围垦后阶段景观变化差异,并对比海滨湿地非围垦区和围垦区景观结构、景观格局和景观类型转移方面的差异,对于合理开发利用海滨湿地资源,保护湿地环境,促进区域生态、经济与社会和谐发展具有重要的理论意义。滩涂围垦开发直接导致围垦区原有的景观格局发生变化,这种变化伴随着具体垦区开发过程。以海北、海丰和金丰垦区为例,研究发现,围垦区内不同垦区在围垦前后景观变化并不完全—致,某些阶段差异明显： (1)各垦区自然景观不断向人工景观转移；海北和海丰垦区斑块形状不断趋于简单规则；景观破碎度方面三个垦区分别呈“升—降—升”、“降—升—降”和“升—降”趋势。 (2)不同围垦阶段垦区景观变化对比方面：围垦前,各垦区景观面积和斑块形状变化差异不大,而由于垦区位置距海远近对植被分布或扩散产生影响,导致垦区景观破碎度变化差异明显；围垦期间各垦区景观格局变化较一致；围垦后,各垦区景观格局变化也基本维持围垦末期状态,除非受新一轮人类活动干扰。盐城国家级自然保护区核心区,由于受国家政策的强烈保护成为天然的非围垦区,将非围垦区和围垦区景观变化进行对比,能直观反映围垦对海滨湿地景观带来的影响。 (1)景观结构方面：以自然驱动力为主导的非围垦区,始终以自然景观为主,自然植被面积整体上升,且主要为芦苇和互花米草湿地；以人为驱动力为主导的围垦区,景观结构由自然景观占主导转为人工景观为主,自然植被除互花米草外均大面积减少,人工景观内部景观类型也存在相互转移,景观变化复杂。(2)景观格局方面：非围垦区由于芦苇和互花米草斑块快速扩张,使得景观斑块形状趋于复杂、自然。景观破碎度,自1995年以后变幅较小,且保持在较低水平。互花米草种植与扩散,使得景观多样性整体呈上升趋势；围垦区由于受人类活动强烈干扰,人工景观面积比例不断增大,整体景观趋于简单规则；景观破碎化程度上升明显；由于水产养殖塘斑块优势性不断上升,景观多样性变化整体呈下降趋势。 (3)景观类型转移方面：非围垦区景观类型质心移动具有距离较短、方向相对单一以及时间较缓的特征。而围垦区景观类型质心移动更多地表现出距离较长、方向无序以及具有突发性的特征。
[Abstract]:In recent years , with the development of social economy and the urgent demand for land , the landscape pattern of reclamation area has changed greatly . In recent years , with the development of social economy and the landscape structure , landscape pattern and landscape type transfer in reclamation area , it is found that the landscape change of reclamation area is not perfect after reclamation .
The shape of patch in Haifeng and Haifeng Reclamation Area tends to be simple and regular ;
( 2 ) There is no significant difference in landscape area and shape change of reclamation area before reclamation , and the difference of landscape fragmentation degree in reclamation area is obvious due to the influence of the location of reclamation area on vegetation distribution or diffusion .
The landscape pattern of each reclamation area was more consistent during reclamation ;
After reclamation , the landscape pattern change of each reclamation area is basically maintained at the end of reclamation , unless it is disturbed by a new round of human activities . In the core area of Yancheng National Nature Reserve , it can directly reflect the influence of reclamation on the coastal wetland landscape due to the strong protection of the national policy .
In the reclamation area dominated by man - made driving force , the landscape structure is mainly changed from natural landscape to artificial landscape , and natural vegetation is reduced in large area except Spartina alterniflora . The landscape pattern is complicated . ( 2 ) landscape pattern : Because of the rapid expansion of reed and Spartina alterniflora , landscape pattern tends to be complex and natural .
Due to the strong interference of human activities , the proportion of artificial landscape area increases continuously , and the overall landscape tends to be simple ;
The degree of landscape fragmentation increased obviously ;
( 3 ) The landscape type centroid movement of non - reclamation area has shorter distance , relatively single direction and relatively slow time .
【学位授予单位】：南京师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P901;P748

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