论文部分内容阅读
互花米草是中国东部河口滩涂湿地主要入侵物种之一,其与本地物种芦苇竞争生长,形成了大范围的混合交错带。该交错带是研究湿地生态系统动态变化的重要信息,但因2种物种光谱的相似性及其在交错带的组成复杂性,使利用遥感技术提取交错带难度较大。因此,本文提出了一种将二者生长物候差异与其光谱特征相结合,考虑二者海陆位置分布差异,运用实测剖面观测数据确定光谱指标和阈值的综合提取方法。运用高分一号多光谱遥感数据,通过分析不同时相互花米草与芦苇冠层光谱差异,确定用来提取混合交错带的高分遥感影像,实现了研究区互花米草-芦苇混合交错带的提取。结果表明:不同时相宜选用不同的提取指标,本研究中在春季选择了近红外波段反射率,而秋季则选择了红波段反射率;2个时相的混合交错带范围存在明显差异,客观反映了互花米草与芦苇在不同季节的竞争状况。
Spartina alterniflora is one of the major invasive species in the estuarine wetland in east China’s estuarine waters. It competes with native species of reed to grow and forms a wide range of mixed ecotone. The interlaced zone is an important information for studying the dynamic changes of the wetland ecosystem. However, the similarity of the spectra of the two species and their complex composition in the interlaced zone makes it difficult to extract the interlaced zone by remote sensing. Therefore, this paper presents a method of combining the difference of growth phenology with its spectral features and taking into account the differences in the distribution of land and sea between the two, and using the observed data to determine the spectral index and threshold. By using the high score one multi-spectral remote sensing data, the spectral difference of the canopy grass and the reed can not be determined at the same time, and the hypersensitive remote sensing images extracted from the mixed interlaced zone were determined. Band extraction. The results show that different extraction indexes are not suitable at the same time. In this study, the reflectivity of the near-infrared band was selected in the spring and the reflectivity of the red band was chosen in autumn. The range of the mixed interlaced band of the two phases was obviously different Spartina and reed compete in different seasons.