Table 20.2 Multispectral indices related to leaf and canopy water content
Index
Abbreviation Equation
a
Author
Comments
Normalized Difference
Vegetation Index
NDVI
(R
850
À R 680 )/(R
850 +
R 680 )
Rouse et al. (1974),
Tucker (1979)
–
Normalized Difference
Infrared Index
NDII
(R
850
À R 1650 )/(R
850 +
R 1650 )
Hardisky et al.
(1983)
Also see Ji et al. (2011)
Leaf Water Stress Index LWSI
Àlog[1 À (R
850
À R 1650 )]/
Àlog[1 À (R
850
À R
0
1650 )]
Hunt et al. (1987)
R
0
1650 is the reflectance at full turgor
(RWC
¼ 100%)
Moisture Stress Index
MSI
R 1650 /R
850
Hunt and Rock
(1989)
Defined for Thematic Mapper Bands 5 and 4
Global Vegetation
Moisture Index
GVMI
[(R
850 + 0.1)
À (R
1650 + 0.02)]/
[(R
850 + 0.1) + (R
1650 + 0.02)]
Ceccato et al.
(2002a, b)
See also Dasgupta and Qu (2009)
Shortwave Infrared
Water Stress Index
(a) SIWSI
(6,2)
(a) (R
1650
À R 850 )/(R
1650 +
R 850 )
Fensholt and
Sandholt (2003)
(a) SIWSI (6,2)
¼ ÀNDII
(b) SIWSI
(5,2)
(b) (R
1240
À R 850 )/(R
1240 +
R 850 )
(b) SIWSI(5,2)
¼ ÀNDWI
Normalized Difference
Water Index
NDWI
(R
850
À R
1240 )/(R
850 + R
1240 )
Gao (1996)
Designed for MODIS bands 2 and 5
Simple Ratio Water
Index
SRWI
R 850 /R
1240
Zarco-Tejada et al.
(2003)
–
Water Index
WI
R 900 /R
970
Pen ˜uelas
et al.
(1993, 1997)
–
Maximum Difference
Water Index
MDWI
(R
1650
À R 1500 )/(R
1650 +
R 1500 )
Eitel et al. (2006)
R 1650 and
R 1500 are about the max and min
R
between 1500 and 1750 nm
Shortwave Angle Slope
Index
SASI
(R
850 ,
R 1650 ,
R 2200 )
Khanna et al. (2007) Angle formed at
R 1650 between
R 850 and
R 2200
Vegetation Water Stress
Index
VWSI
1
À [(M
1
À M)(R 850
À M 2
R 1650
À I 2 )/
(M
1
À M 2 )(R
850
À M R 1650 )]
À [I
2 (M
1
À M) +
I 1 (M
2
À M)]
Ghulam et al. (2008)
M 1 ,
M 2 ,
I 1 ,
I 2 are points bounding a trapezoid in
NIR-SWIR image feature space
a
R
λ is the reflectance at
λ nanometers wavelength
342
E.R. Hunt Jr. et al.