基于面向对象分类方法的乌苏里江流域中俄跨境区域湿地景观动态研究

Study on Dynamic of Wetlands Landscape in the Trans-boundary Regions between China and Russia of Ussuri River Watershed based on Object-oriented Classification Method

选取乌苏里江中下游干流50km缓冲区为研究区,以1989、2000和2013年的Landsat TM、OLI遥感影像为数据源,利用面向对象的分类方法获取湿地信息;在GIS技术支持下,选取斑块类别面积（CA）、面积所占比例（PLAND）、最大斑块面积指数（LPI）、平均斑块面积（AREA-MN）、斑块数（NP）、斑块密度（PD）等景观格局指数,分析了研究区1989～2013年湿地的景观格局动态特征。结果表明：面向对象的分类方法能够准确提取湿地信息,并且有效地避免＂椒盐现象＂;1989～2013年,该区水田、水库/坑塘、运河/水渠、灌丛沼泽增加和河流、湖泊、草本沼泽、森林沼泽减少;大量草本沼泽转为水田为该区湿地变化主要特征;1989年湿地类型以草本沼泽为主,2013年水田的斑块面积略高于草本沼泽斑块面积;湿地景观变化区主要分布于中国一侧的挠力河流域和穆棱河流域;天然湿地景观破碎化程度逐年加深,人工湿地景观趋于聚集,人为干扰是导致湿地景观格局变化的主要动力;中俄两国境内湿地景观变化程度差异显著,中国境内大量天然湿地转为人工湿地;俄罗斯境内的湿地变化微小,天然湿地保存较好。农田垦殖是导致两国湿地景观破碎程度差异的主要原因。

The paper selected 50km buffers of the middle and lower reaches in the Ussuri River as the study area.Using the object-oriented classification method extracted the wetland information from remote sensing images.Supported by GIS technology, the paper selected Total Class Area（CA）,Percentage of Landscape （PLAND）, Largest Patch Index （LPI）, Patch Area Mean （AREA-MN）, Number of Patches （NP）, Patch Density（PD）et al.to analyze the dynamic characteristics of landscape metrics during 1989-2013.Results in- dicated that the wetland information could be accurately extracted by object-oriented classification method,and the ＂salt and pepper＂ was avoided;During 1989-2013 period, wetland of the region changed dramatical- ly,and the main characteristics of change was that paddy fields, reservoirs/ponds, canals/ditches, shrub swamps increased and rivers, lakes ,forest marshes, herbaceous marshes reduced; Herbaceous marshes sig- nificantly reduced and the most were converted into paddy fields;The main wetland type was herbaceous marshes in 1989, and the paddy fields was over herbaceous marshes of the area by 2013;The dominating re- gions of wetland changes were distributed in Naoli River basin and Muling River basin in China.Fragmenta- tion of natural wetland landscape gradually deepened, constructed wetlands tended to gather. Human dis- turbance is the main driving forces of wetlands landscape pattern changes.Difference of wetlands landscape change was significant in the territory in China and Russia. Because a lot of herbaceous marshes trans- formed into paddy fields, natural wetlands lost seriously and constructed wetlands increased significantly in China and Russia.The changes of wetlands were insignificant ,and natural wetlands was preserved better in Russia.Farmland cultivation was a major cause of differences of wetland landscape fragmentation between China and Russia.