The NDVI was calculated by NDVI¼ (NIR- RED)/(NIR þ RED)
where NIR is the near-infrared band response for a pixel and RED is
the red band (Hassan, 2000) (Fig. 2). Computed NDVI images of the
Matang Mangrove Forest showed high to low vegetation areas in
1993, 1999, and 2011 images.