REMAPPING the BLANG OI VILLAGE AREA in the MEURAXA DISTRICT, BANDA ACEH AFTER the 2004 TSUNAMI

REMAPPING the BLANG OI VILLAGE AREA

in the MEURAXA DISTRICT, BANDA ACEH AFTER the 2004 TSUNAMI

ABSTRACT

                Carrying out a proper the development rural areas in small scales requires accurate and updated geo-spatial data and information, which are traceable by using  Global Positioning System (GPS) navigation instruments. This research is intended to  recover the  positions of buildings and fishponds processes, wiped out by the 2004 tsunami, Blang Oi Village by using  GUI on Matlab.

            The study was conducted in Blang Oi Village based on the IKONOS satellite images at pre and post-tsunami times, and the  QuickBird satellite image after reconstruction with the scale of 1:2,000,  436 coordinate points  obtained with GPS Garmin RING 530HCx hand help receiver . Geometric corrections ware performed on the three satellite images by placing  four  control points on the individual image for conformation the  Sobel operation to differentiate  object and background. Was used morphological operations ware exploited to connect  the disconnected boundary lines by the Sobel operation, and  with mean, median and Wiener filter on 3x3 windows to minimize noises in the image. The corrected GIS was developed on segmentated,  rastered, and  vectored images by applying  UTM zone coordinate system 46N Dantum WGS 1984.

           

The location of construction object and the lost  pond borders were detected by overlaying segmentation image for pre- tsunami and   by using  raster image at post-tsunami times. The differences of construction object positions developed were indicated by overlaying segmentation image pre-tsunami by using raster image after the reconstruction period. The GPS data were used to check the  positions of construction coordinate points on the Google Earth location data. The results show the re-constructed objects were not accurately detected, while for the ponds object the accuracies are superficies good detected. Manually digitalization results for the pond objects  through the use of ArcGis was similar to  the result of thresholding 40-based Sobel operation  but different for building objects.

Keywords: Segmentation, Overlay, Coordinate, Satellite Image, GPS