图像机理方法提取水体信息的应用分析

在以Landsat ETM+为数据源,详细分析水体与背景地物的地表反射率及波谱特征的基础上,对比阈值法、谱间关系法、指数模型法和条件函数四种方法在城镇水体和山区水体提取上的差异.对两个研究区试验结果表明:MNDWI比值模型的水体提取精度最高,信息量相对完整,其他四种方法在细小水体的提取效果上也不如MNDWI.为验证结论的准确性,本文选取了福建省不同时期、不同地区的不同水体类型进行试验.其中城镇与山区的水体提取方法的优劣结果与上文的结论一致.湖泊与河口区的水体与前两种类型的水体的地表反射率值曲线不同,但这两个区域的水体与其他地物的MNDWI的反差值在几种提取方法中为最大.反差值越大越有利于水体与背景地物的区分.MNDWI在这两种水体类型的提取上也取得较好的效果.试验表明相对其他四种方法,MNDWI比值模型能够便捷、快速、准确地提取水体信息,且具有较强的适应性.

Study of Water Body Information Extracting Methods Based on Spectrum Characteristics

Landsat ETM+data are used to extract the water bodies in build-up and mountainous areas based on the spectrum characteristics of water and background objects,by the methods of threshold,spectro-photometric, index models and criteria function,respectively.The results of the test indicate that MNDWI index model has the best performance in the water body extracting,while the other four methods mix the other objects information with water body.Studies are also carried out on other types of water body in differe...