Dr. Ana Maria Ferreira da Silva
Two matters of debate in meandering river morphology and morphodynamics
Meandering is one of the more common plan shapes acquired by rivers, especially in the lowland alluvial plains. Owing to this reason, intensive and systematic research on meandering river morphology and morphodynamics has been carried out for over 80 years. Yet, several aspects of meandering river behaviour remain subjects of ongoing debate. The lecture will focus on two such aspects, one pertaining to the shape acquired by meanders and the other to cross-circulatory motion, and will include a formulation of the challenges and discussion of recent and pertinent research findings.
Synthetic Tropical Cyclone Track Generation for Risk Analysis
under Current Climate and Future Climate Scenarios
Regardless of whether they are called hurricanes or typhoons, the tropical cyclones are one of the deadliest and most damaging recurring natural hazards. Some dictionaries define it simply as “a localized, very intense low-pressure wind system, forming over tropical oceans and with winds of hurricane force”. Using a more technical language, they can be defined as “the generic term for a non-frontal synoptic scale low-pressure system over tropical or sub-tropical waters with organized convection (i.e. thunderstorm activity) and definite cyclonic surface wind circulation.” They can also be regarded as “thermodynamic engines that convert heat into mechanical energy”. Tropical cyclones, landfalling, or cruising close to the shore, are multi-hazard events that generate extreme winds and rainfall accompanied by coastal flooding due to storm surge and inland riverine flooding due to combined effect of extreme rainfall and storm surge height. They cause every year loss of life and damages to infrastructures and property in billions of dollars.
The study of the risks due to tropical cyclones suing solely historical data is challenging because relatively a small number of tropical cyclones occur each year in different ocean basins, and even smaller number of them make landfall. To overcome this difficulty, the approach is to develop a tool that can generate a large number of physically based synthetic hurricane tracks using the weather data. Since it would be physically based, it is expected that such a tool can also be used for studying the risks due to tropical cyclones under future climate scenarios.
Dr. Mustafa Altınakar