鄱阳湖湖岸带景观变化

湖岸带是水陆生态系统过渡带,是人类活动最集中的区域之一,也是生态系统较为脆弱的区域。湖岸带具有重要的生态功能,湖岸带研究对于湖泊湿地生态系统保护具有重要意义。利用1995年,2000年,2005年和2010年4个时期的同水位条件下鄱阳湖湿地湖岸带遥感影像,对鄱阳湖湖岸带的景观进行了研究,结果表明,鄱阳湖湖岸带各种景观类型的面积变化显著,2010时期的水体面积较1995年、2000年和2005年时期减少近100km~2,绿地面积2010年较1995年减少近500km~2,建设用地和裸地面积2010年较1995年增加700km~2以上。景观指数变化明显,景观斑块数量逐年上升,最大斑块面积逐年减小,周长面积分形指数逐年加大,辛普森和香浓景观多样性指数逐年增大,表明湖岸带景观破碎化程度逐年加强。通过遥感影像解译结果综合分析,鄱阳湖湖岸带建设用地和裸地增加主要表现在沙化土地面积、交通建设用地面积和居民建筑建设用地的增加有关。

Riparian landscape change in Poyang Lake

Riparian Lake is an ecotone between aquatic ecosystem and terrestrial ecosystem, and it is one of the most concentrated areas of human activity, consequently, the ecosystem of riparian lake is very fragile. Riparian Lake is one of the most serious degenerative ecosystems because of the disturbance of human activity with the rapid development of economy and society. Poyang Lake is the largest freshwater lake in China and one of the world''s important wetland recognized in the Ramsar Convention on Wetlands. There is rich in biodiversity, supporting numerous species of invertebrates, fish, birds and mammals including the White Crane (Grus leucogeranus), Cygnet (Cygnus columbianus), Chinese sturgeon (Acipenser sinensis), and Cowfish (neophocaena phocaenoides). The wetlands provide an important range of ecosystem services; and their protection is an important concern both domestically and abroad. In order to compare changes in the riparian lake landscape, this paper analyzed riparian lake landscape with RS images in four different periods under the same condition of similar water level in 1995, 2000, 2005 and 2010. Changes in landscape spatial pattern were analyzed. Changes in landscape index, area of landscape types, and landscape types were very distinct in the riparian lake, the area of water body decreased more than 100km² in 2010 than in 1995, and the area of vegetation decreased more than 500km² in 2010 than 1995; however, the artificial and bare land increased almost 700km² in 2010 than in 1995. The total Landscape Patches increased, the Largest Patch Area decreased, the Perimeter-Area Fractal Dimension lessened, and Diversity Index of Shannon''s and Simpson''s increased from 1995 to 2010. Changes of landscape index explained fragmentation level of riparian lake landscape strengthened. Furthermore, the driving force was analyzed according to the historic materials and RS images, the loss of area in water body and vegetation because of the increase of artificial and bare land, mainly sandy soil and urbanization land.