基于Corona和Spot-5影像的图们江下游敬信湿地变化研究

Change of Jingxin Wetland in the Lower Reaches of Tumen River Based on Corona and Spot-5 Images

采用1964年的Corona影像和2004年的Spot-5影像作为数据源,结合"3S"技术与实地考查资料,对图们江下游敬信湿地信息进行了提取与分类,分别得到了研究区1964年和2004年的湿地分类图;通过建立研究区的湿地动态变化特征模型,从各类型湿地的面积变化和斑块变化两个角度,研究敬信湿地的变化特征及其成因。结果表明,研究区各类型湿地在气候变化、人类活动等因素的影响下发生了不同程度的变化,与1964年相比,2004年研究区人工湿地面积增加了16.923km2,这主要是修建龙山水库以及水田、养鱼池和孵化池面积大量增加所致;而自然湿地受到严重破坏,面积减少了17.33km2,河流和沼泽面积都减少了50%以上。研究区河流的斑块数急剧减少,沼泽湿地的斑块破碎化程度加剧,河流和沼泽湿地的斑块分维值明显下降,大面积沼泽被开发成水田,这两种湿地的空间自我相似性逐渐变差。研究区部分湖泊被开发利用,人为束水使得水面面积扩大,当地居民为了发展经济,在湖泊中从事鱼类养殖以及用湖泊水进行农业灌溉等活动,研究区人类活动干扰日趋严重。

Based on several Corona images in 1964 and Spot -5 images in 2004, combined with the utilization of GIS, RS and GPS technologies to extract and classify the information about Jingxin wetland in the lower reaches of Tumen River while done with the contrasting wetland classification maps of the research area of 2 years in this paper. By constructing the dynamic change model of this area, characteristics of the changes of the wetland land-scape in this area have been studied from the perspectives of the area and fragmental change of various wetland types respectively and the causes for the changes also have been analyzed. The results indicated that all wetland types in the area have changed under the influences of climate change and human activities. The area of artificial wetland has increased by 16. 923 km^2 by the reasons of the establishment of Longshan Reservoir as well as the expansion of fishing ponds and hatchery ponds, whereas the natural wetlands have been destroyed severely, with an area reduction up to 17.33 km^2. Apart from the drastic area changes, the fragmentation degree of wetland pat- ches were also altered tremendously, which was shown in the sharp reduction of patch number of rivers and the highly fragmentation of marsh patches. The obvious drop of fractal dimension of Lacustrine and Riverine wetlands reflected both the weakening of the spatial similarity of these two and the huge disturbance by human activities. The study further found the lake areas in the area had increased during their transformation into artificial reservoirs partially in that the local residents expanded the lakes constantly for fishery and agricultural irrigation putposes