Locating lost waterways through image registration of old and recent maps of Manila

Floods are common problems in Metro Manila during the rainy season. This can be attributed to the area's geographical features which have changed through time. This paper aims to locate changes that occurred in the water areas and identify lost waterways using past and present maps of Manila. Map image registration is performed to align the images and analyze their differences. Two algorithms are presented in this study, which differ in finding the scale and translation needed for alignment. After overlaying the old and recent maps, differences between the waterways are highlighted. Results of both algorithms show some lost waterways near Espana, Sampaloc and Quiapo which might be the cause of flooding in these areas nowadays. With this map alignment, one can possibly simulate the effect of current amounts of rainfall if it happened 100 years ago.