TY - CONF
T1 - Reconstructing the Ganges delta from satellite imagery, connecting individual channels into rivers
AU - Addink, E.A.
AU - Kraaijenbrink, P.D.A.
AU - Kleinhans, M.G.
PY - 2016/4/8
Y1 - 2016/4/8
N2 - The Ganges delta is a very dynamic system, because of the large amounts of sediment that are transported here down from the Himalayas and tectonic activity that can abruptly change regional topography. In a satellite image one sees a mixture of active and fossil channels. Once a channel is abandoned, it can remain water-filled, become sediment-filled, be overgrown by vegetation or a combination, thus losing its unique spectral signature. We used object-based image analysis to identify meander channels by using shape variables at multiple scales. The result is a map of individual bended channel segments. We developed an automated method to connect these segments into former meander belts and estimated historical river discharge from an empirical relation between river discharge, channel geometry and meander wavelength. The result was a network of four main channel belts. The associated paleodischarge showed that two of them were probably the main course of the Ganges river for a significant amount of time, while the other two can have been distributaries but not the main course. This method can be applied to other river deltas as well as other processes that create networks over time, such as lava flows.
AB - The Ganges delta is a very dynamic system, because of the large amounts of sediment that are transported here down from the Himalayas and tectonic activity that can abruptly change regional topography. In a satellite image one sees a mixture of active and fossil channels. Once a channel is abandoned, it can remain water-filled, become sediment-filled, be overgrown by vegetation or a combination, thus losing its unique spectral signature. We used object-based image analysis to identify meander channels by using shape variables at multiple scales. The result is a map of individual bended channel segments. We developed an automated method to connect these segments into former meander belts and estimated historical river discharge from an empirical relation between river discharge, channel geometry and meander wavelength. The result was a network of four main channel belts. The associated paleodischarge showed that two of them were probably the main course of the Ganges river for a significant amount of time, while the other two can have been distributaries but not the main course. This method can be applied to other river deltas as well as other processes that create networks over time, such as lava flows.
M3 - Abstract
ER -