Methods

The study area will include the Northwestern tip of Banda Aceh,Indonesia, located on the Island of Sumatra. This city is infamous for the devastating hit it took after the 2004 Tsunami.The data for our project has been collected from many sources.

The night light images of Indonesia were taken from the National Geophysical Data Center (NGDC). To do this, we downloaded the night light image of the world of each year and loaded this onto ENVI and subset the country of Indonesia. When our region was subset, we density sliced the image to show concentration of light in color. Represented in our project are night light images of Indonesia from the years 2003 to 2009. These images were downloaded separately and then organized in an efficient way to compare the changes in night light over this seven year period. Using ENVI, we compared night light from 2004 to 2005. This was done by computing a difference map by combining the 2004 and 2005 images and comparing the similarities and differences in where light was coming from.

To compare geographical and geophysical changes from before and after the Tsunami we downloaded Landsat images of Banda Aceh from data discover tool, Glovis. These were all extracted from the USGS Earth Resources and Observation Center website. To compare these changes from this region, we downloaded a before picture taken in May,2004. Our after picture we downloaded was taken in February 2005, and our present picture was taken in January 2009. After unzipping each image twice, we loaded the three images into ENVI. We then used the algorithm to replace the bad values of the pictures, which were diagonal black lines running through each image. When our pictures were clear we changed from from the RGB view to the Infrared view and compared the before, after, and present effects that the 2004 Tsunami had on Banda Aceh, Indonesia. When this was done, we were able to see clearly the differences in vegetation and land destruction after the Tsunami.

To retrieve our elevation data, we brought up the Global Land Cover Facility homepage. We then entered the Earth Data Science Interface and downloaded the portion of Indonesia from the world map. After unzipping the image and loading it onto ENVI we had elevation data for Banda Aceh for the year 2000.