چکیده (انگلیسی):

Over the last two decades there has been a revolution in our ability to map and monitor large areas of subaerial topography using technologies such as radar and near-infrared Light Detection and Ranging. The Multispectral Remote Sensing (RS) Satellite ‘WorldView-2’ imagery has the ability to measure water depth up to 25m. Studies have been conducted based on the band ratio algorithm to determine water depth in the study area the Ganges River in Bangladesh. This method is able to generate accurate depth measurements at points or along transects, and also offer more flexible, efficient and cost-effective means of mapping bathymetry over broad areas. There are two methods are available to derive bathymetry from remote sensing imagery which are “linear method” and “ratio method”. The linear method is depended upon bottom type albedo. While different bottom types at the same depth would be incorrectly calculated for one of these two substrates. The accuracy of the retrieved bathymetry varies with water depth, with the accuracy substantially lower at a depth beyond 12 m. Other influential factors and challenges include water turbidity and bottom materials, as well as image properties.