Improved Landsat-Based Water and Snow Indices for Extracting Lake and Snow Cover/Glacier in the Tibetan Plateau

Identifying water and snow cover/glaciers (SCG) accurately is of great importance for monitoring different water resources in the Tibetan Plateau. However, discriminating between water and SCG remains a difficult task because of their similar spectral characteristic according to the physical princip...

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Bibliographic Details
Main Authors: Dajiang Yan, Chang Huang, Ning Ma, Yinsheng Zhang
Format: Article
Language:English
Published: MDPI AG 2020-05-01
Series:Water
Subjects:
Online Access:https://www.mdpi.com/2073-4441/12/5/1339
Description
Summary:Identifying water and snow cover/glaciers (SCG) accurately is of great importance for monitoring different water resources in the Tibetan Plateau. However, discriminating between water and SCG remains a difficult task because of their similar spectral characteristic according to the physical principles of remote sensing. To efficiently distinguish different kinds of water resources automatically, here we proposed two new indices including: (i) the normalized difference water index with no SCG information (NDWI<sub>ns</sub>) to extract lake water and suppress SCG: and (ii) the normalized difference snow index with no water information (NDSI<sub>nw</sub>) to extract SCG and suppress lake water. Both new water and snow indices were tested in the Tibetan Plateau using Landsat series, showing that the overall accuracies of NDWI<sub>ns</sub> and NDSI<sub>nw</sub> were in the range of 94.6–97.0% and 94.9–97.0% in mapping the lake water from SCG and mapping the SCG from lake water, respectively. Further comparisons suggest that these new two indices improved upon the previous normalized difference snow index/modified normalized difference water index (NDSI/MNDWI) in mapping the water body and SCG. While the present study only focuses on the validation over certain areas in Tibetan Plateau, the newly proposed NDWI<sub>ns</sub> and NDSI<sub>nw</sub> have the potential for better monitoring the lake water and snow/glacier areas over other cold regions around the globe.
ISSN:2073-4441