Analysis of dynamic thresholds for the normalized difference water index

Photogrammetric Engineering and Remote Sensing
By: , and 



The normalized difference water index (NDWI) has been successfully used to delineate surface water features. However, two major problems have been often encountered: (a) NDWIs calculated from different band combinations [visible, nearinfrared, or shortwave-infrared (SWIR)] can generate different results, and (b) NDWI thresholds vary depending on the proportions of subpixel water/non-water components. We need to evaluate all the NDWIS for determining the best performing index and to establish appropriate thresholds for clearly identifying water features. We used the spectral data obtained from a spectral library to simulate the satellite sensors Landsat ETM+, SPOT-5, ASTER, and MODIS, and calculated the simulated NDWI in different forms. We found that the NDWI calculated from (green - swm)/(green + SWIR), where SWIR is the shorter wavelength region (1.2 to 1.8 ??m), has the most stable threshold. We recommend this NDWI be employed for mapping water, but adjustment of the threshold based on actual situations is necessary. ?? 2009 American Society for Photogrammetry and Remote Sensing.
Publication type Article
Publication Subtype Journal Article
Title Analysis of dynamic thresholds for the normalized difference water index
Series title Photogrammetric Engineering and Remote Sensing
DOI 10.14358/PERS.75.11.1307
Volume 75
Issue 11
Year Published 2009
Language English
Publisher Ingenta
Contributing office(s) Earth Resources Observation and Science (EROS) Center
Description 11 p.
First page 1307
Last page 1317
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