基于OLI影像的几种常用水体提取方法对比研究

Comparative Study of Several Common Water Extraction Methods Based on OLI Image

选取安徽省西南部的沿江平原和皖南山区为研究区,以Landsat8 OLI影像为数据源,基于面向对象的思想,比较阈值法、谱间关系法、NDWI指数、MNDWI指数、EWI指数法、CIWI指数法、PRWI指数法在平原地区和山地地区的水体信息提取的优势与不足。试验结果表明,7种方法均可以有效提取,综合来看,阈值法较适合平原地区的水体信息提取,谱间关系法适合山地地区的水体信息提取,MNDWI指数和阈值结合水体指数法较适合平原地区的水体信息提取。从精度评价角度看,阈值法提取OLI影像的水体信息效果最差,MNDWI指数提取的水体信息精度最高。

This study took plain area and mountain area in Anhui province as an exsample and based on Landsat Oli image,comparatively studied from three aspects： discrimination,water error rate and area accuracy on the single-band threshold method,the multi-band spectral relationship method,NDWI and other four normalized water indexes： MNDWI,EWI,CIWI and PRWI,to show accuracy rating of extracting water information. The results indicated that all of six methods can extact water information. But the single-band threshold method,MNDWI and PRWI are better at extracting water information from plain area. The multi-band spectral relationship method is better at extracting water information from mountain area. On area accuracy asprect,the single-band threshold method is the worst method of extracting water information of OLI image. MNDWI is the best method of extracting water information of OLI image.