Band combination method in the recognition of vegetation remote sensing is widely used, the effect is
better. It is based on the physical characteristics of mangrove forests and the spectral characteristics of
mangroves.Making use of the combination between the different bands to highlight the most obvious
difference between spectral characteristics.It includes vegetation index, band ratio and principal
component analysis and other methods. Vegetation index (Blasco et al.1986; Chaudhury 1990; Jensen
etc.1991), including normalized difference vegetation index NDVI, orthogonal index (tassled cap
transformation). Chaudhury [9] use the Landsat TM near-infrared bands B5, B7 of the ratio: ((B5-B7) /
(B5 + B7)). Blasco, etc. from the red and infrared SPOT XS bands 2,3, calculate a normalized number of
NDVI = ((B3-B2) / (B3 + B2)). Jensen etal associate [10] survey data from the field with four different
vegetation indices obtained from the SPOT XSm to associate to make the ratio of image classification.