Vegetation water content estimation using Hyperion hyperspectral data

This paper used water related vegetation indices calculated from Hyperion image to make water content mapping. The study area is located in Zhangye city, Gansu province in Heihe River Basin of China. Hyperion hyperspectral data was acquired on September 10, 2007. Using Hyperion reflectance of 35 plots, the relationships between vegetation indices and Equivalent Water Thickness (EWT) were calculated. R² between Enhanced Vegetation Index (EVI) and EWT was 0.325. The correlations between new vegetation indices and EWT were higher. The highest R² was 0.377 between (EVI×NDVI)/MSI and EWT, so (EVI×NDVI)/MSI acquired from Hyperion image was used to make EWT mapping. The range of EWT was 0.0127-0.0281 g/cm² with an average of 0.01479 g/cm². Zhangye city, buildings and the edge of desert area had the lowest EWT, ranged from 0.0127 g/cm² to 0.013 g/cm², while non-eared and non-intercropped corn had high EWT(0.015-0.018 g/cm²). The sources of errors were also discussed.