NDWI (Gao, 1996)
Normalized Difference Water Index (NDWI) : NDWI = (NIR-MIR)/(NIR+MIR)
Also called NDII (Normalized Difference Infrared Index) (Hardisky, 1983), LSWI (Land Surface Water Index) (Xiao, 2005), and NDMI (Normalized Difference Moisture Index) (Xu, 2006).
Reference: Gao, B.C., 1996: NDWI - A normalized difference water index for remote sensing of vegetation liquid water from space. Remote Sensing of Environment, Vol. 58: 257-266