Study of information extraction method of water body based on Mapping satellite-1 imagery

摘要

To find a suitable water extraction method from Mapping satellite-1 imagery in urban areas, this paper compared the results of different water extraction methods and studied the effect of building shadow on water extraction. Taken parts of Xinjiang (Beitun of Irtysh river Basin) as the study area, Mapping satellite-1 imagery as data sources, single-band threshold method, Normalized Difference Water Index (NDWI), Normalized Difference Vegetation Index (NDVI), and spectral relationship method based on spectral area were applied respectively to extract information of water body. The results of information extraction by use of the four methods were compared to determine the optimal method for water body extraction. The results showed that, for Mapping satellite-1 imagery, single-band threshold method and spectral relationship method which based on spectral area were effective to eliminate classification errors cased by shadows from buildings, fast, easy and accurate to extract information of water body from urban areas. In addition, the spectral relationship method based on spectral area also had the character of extracting small tributary rivers.