Flood hazard assessment in Bangladesh using NOAA AVHRR data with geographical information system

Flooded area and flood hazard assessment in Bangladesh were evaluated using remote sensing (RS) data with the geographical information system (GIS). Image data from the National Oceanographic and Atmospheric Administration (NOAA) Advanced Very High Resolution Radiometer (AVHRR) were used to analyse Bangladesh's historical flood event of 1988, which sets a hundred-year record for the inundated areas, with severe damage occurring throughout this region. Cloudy skies often occur during big floods, and visible and infrared rays observed by the NOAA AVHRR cannot penetrate cloud cover. We therefore proposed a new algorithm for classifying cloud covered pixels into water or non-water categories. In order to estimate the flooded area accurately, the images taken during the flood and dry season which were classified into water and non-water categories were superimposed. A new flood hazard map, created from the land cover category and elevation height data which were ranked by flood affected frequency, can be used to evaluate flood risk using only RS data and elevation height data. Copyright (C) 2000 John Wiley & Sons, Ltd.