“…The spectral reflectance (in SWIR regions at ∼1400 and ∼1900 nm) also influences by plant water content. Researchers have studied these spectral changes to relate them with phytoaccumulation of metals [Horler et al, 1980;Clevers and Kooistra, 2003;Schuerger et al, 2003;Clevers et al, 2004;Kooistra et al, 2004;Dunagan et al, 2007;Sridhar et al, 2007a,b;Su et al, 2007]. Most studies used various vegetation indices (ratios or linear combinations of two or more spectral wavelengths [Bannari et al, 1995]) and rededge position (a sharp transition between red and NIR wavelengths; positively related to chlorophyll concentration; [Horler et al, 1983;Dawson and Curran, 1998]) as an indication of plant stress.…”