近17年鄱阳湖区景观格局动态变化研究

Dynamic changes of landscape pattern in Poyang Lake region over the recent 17 years

通过对1989、1999和2006年3期遥感影像进行解译,借助ARCGIS、FRAGSTATS等软件对鄱阳湖区近17年景观格局动态变化进行分析。结果表明:近17年湖区景观空间结构在自然因素和人类活动的影响下发生显著变化。从景观水平上看,湖区整体景观的破碎化程度不断增大,各斑块类型在空间上的分布趋于均匀和分散,景观中斑块的形状渐趋不规则,复杂程度加大。在斑块类型水平上,研究区水体的破碎化程度增加,斑块向着小型化方向发展,斑块之间的结合度降低,形状逐渐变得复杂,水体斑块之间的水力联系减弱;草地和林地的空间结构相对稳定,变化并不显著;耕地虽然是研究区的优势景观类型,但在近17年间,其优势地位被逐渐削弱,破碎化程度也在逐渐加大,斑块形状的规则性降低,各斑块之间的分离性加大;滩地的变化主要受水文情势和泥沙淤积的影响,破碎化程度经历了先加大、后降低的过程,最大斑块面积有所增大;建设用地的变化最为明显,其破碎化程度也有所加大,但斑块间的连接程度相对研究初期有所增加;未利用地是研究区面积最小的景观类型,其景观破碎化程度则有所降低,斑块形状也渐趋简单。

Based on the remote sensing images of 1989,1999 and 2006,dynamic changes of landscape pattern in Poyang Lake region were studied with ARCGIS and FRAGSTATS in recent 17 years.The result shows that the landscape pattern of Poyang Lake region had changed significantly due to both natural factors and human activities intervention.Analyzed from landscape level indexes,the landscape fragmentation was increasing,the different landscape patches tended to be uniform and scattered distributed,and the shapes of patches were becoming more complex and irregular.Patch types analysis indicates that the fragmentation degree in water bodies was increasing;the patches were becoming smaller,the shape of patches was more complex,and the hydraulic linkage between water patches was weakening.No evident changes were detected in grassland and forest which presented stable structure.Cropland was the dominant landscape;however,it became more irregular and fragmentized.Bottomland was influenced by hydrological condition and silt deposition more significantly.Its fragmentation degree was increasing during 1989—1999,and decreased in 1999—2006.Variation of construction land was most obvious with increasing fragmentation and patches linkage.Unused land was relative small,the fragmentation was decreasing,and the shape of patches was becoming simpler.