Nightlight Difference Before and After the Tsunami

To get a closer look at the tsunami’s effect on nightlight, we performed a change detection analysis, and created a difference map to easily see changes in lighting from before and after the tsunami. The map shows the light that was present in 2004 but went dim after the tsunami, as well as the new light that came about the year after the tsunami hit. The northwestern edge of the island displays blue (Nightlight Present in 2004 But Not 2005), while the northeastern edge displays red (Nightlight Present in 2005 But Not 2004). This reveals the relocation of the inhabitants from the west to the east, away from the destruction caused by the tsunami.