三江平原洪河自然保护区湿地遥感分类研究

湿地是指陆地上常年或季节性积水或过湿的土地与生长栖息于其上的生物种群构成的独特生态系统,具有重要的生态价值与科学研究价值。研究选取重要国际湿地洪河保护区作为研究区,应用多期LandsatTM影像,采取基于专家经验的监督分类方法进行基于群落尺度的分类,取得了较好的分类效果。研究表明有效的影像增强处理和分类训练区的精确选择是监督分类的关键,基于专家辅助的地理信息系统空间分析方法有助于提高分类精度。依据遥感分类结果定量分析了高度自然状态下的北方半湿润区内陆淡水湿地群落类型的原始空间格局。研究揭示具有从沼泽湿地向草甸湿地明显过渡特征的小叶章-苔草群落占据整个保护区面积过高比例,显示该湿地保护区典型沼泽湿地的现状湿生环境退化特征比较明显,应尽早采取相应措施。

A Study on Classification of Wetland Communities in Honghe National Nature Reserve by Remote Sensing

Wetland is a land with seasonal or yearly water,on which lives with specific vegetations and animals.Wetland specifies with both ecologic and scientific values.With the study area of international importance,supervised classification supported by exports was approached successfully to Landsat TM based on the scale of community.Our research indicated that efficient preprocess of image enhancement and precise selection of signatures is the key to classify succesfully.Spatial structure of virgin riparian wetlands of North China was presented according to the classifiation result of community types.Our research also demonstrated that very high proportion of Ass.Calamagrostis angustifolia-sundry herbs within the study area made it clear the occurent loss of the wettability of study area as typical mires in North China,so that urgent measurements were requested in case of further degeneration.