Submitted to: American Society for Photogrammetry and Remote Sensing Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: November 10, 2005
Publication Date: May 1, 2006
Citation: Hunt, E.R., Yilmaz, T., Jackson, T.J. 2006. Vegetation water content from Landsat 5 thematic mapper during the Soil Moisture Experiment 2004 in Arizona and Sonora [abstract]. American Society for Photogrammetry and Remote Sensing Proceedings. 2006 CDROM.
Vegetation Water Content (VWC in mm H2O or kg H2O/m2) is important for accurate retrievals of soil water content using passive and active microwave sensors. A significant component of VWC is foliar water content, which can be measured using bands in the shortwave infrared (SWIR). Landsat 5 Thematic Mapper data were acquired during the summer monsoon period in Arizona USA and Sonora Mexico as part of the Soil Moisture Experiment 2004 (SMEX04). The Normalized Difference Infrared Index [NDII = (TM band 4 - TM band 5)/(TM band 4 + TM band 5)], was calibrated with field data and applied over the region for imagery in July and August. Vegetation cover type was classified using a decision tree and VWC was assigned using the mean from each class. NDII was varied more within a vegetation cover type than between most cover types, because of the low range of leaf area index with these desert ecosystems. NDII was very sensitive to background soil moisture, so combinations of sensors may be required to estimate VWC.