Kai Chu

Morphodynamic modelling of decadal coastal evolution of German Bight

Studying morphological changes of coastal areas is of great importance for natural disaster prediction and coastal management. Coastal morphodynamic models are useful tools for studying coastal evolution. The first aim of my PhD study is to build a regional morphodynamic model to simulate the hydrodynamics, sediment transport and morphological changes of the German Bight. Morphodynamic numerical models usually show poor performance in detail due to the following reasons:

(1)Complex physical processes and uncertainty of topographical changes.
(2)To meld the longer-term morphological changes with shorter-term processes such as waves and tides is the main challenge for modelers.
(3)Models usually suffer from uncertainty in their parameters.

In my PhD project, I would like to present a novel approach called data assimilation to improve the model performance by melding the model predictions with observations. Observed bathymetric data sets are available from 1982 to 2008 which can be used to be compared with predicted bathymetries from a numerical model. The principle of data assimilation is making sufficient use of both predictions and observations based on their errors. Bathymetry from model runs and observations are combined with weights inversely related to their relative errors. The ‘best’ model state and model parameter sets can be achieved by minimizing the total errors of predicted and observed bathymetry (using cost function). The model is then advanced in time. The main objective of my PhD work is to improve the predictive ability of numerical morphodynamic models with the benefits of data assimilation and further to do long- term coastal evolution analysis of the German Bight. Sensitivity analysis will be carried out to examine the viability of data assimilation.

You can visit the MARUM Coastal Geosciences Group webpage for more information.

January 2008 to April 2009
• Institution: UNESCO- IHE Institute for Water Education, Delft, The Netherlands
• Field of Study: Water Science Engineering: specialization Hydroinformatics
• Qualification: Master of Science (MSc.)

The title of MSc thesis is ‘Process-based and surrogate modeling of fine sediment transport in the Dutch Coastal Zone’. Part of this research was carried out in the framework of the project ‘Morphodynamics of the North Sea and Coastal Defense’ of the Delft Cluster research programme supported by the Dutch government.

September 2002 to July 2006
• Institution: Hohai University, Nanjing, China
• Field of Study: Naval Architecture and Ocean Engineering
• Qualification Bachelor of Science (BSc.)