Flooding can have devastating impacts on people’s livelihood, economy and the environment. An important instrument in flood management is floodplain maps, which assist land planners and local authorities in identifying flood-prone areas, and provide useful information for rescue and relief agencies for their operations. Developing floodplain maps often involves flood inundation modeling. This typically requires precipitation and stream flow data, topographic information, building a hydraulic model and calibration of its parameters. Often however, floodplain maps are built on a single model outcome without an explicit consideration of all the sources of uncertainty in the modeling process.
The research presented in this thesis addresses the uncertainty in flood inundation modeling, which may arise from input data and hydraulic modeling approach. The study area is the Sungai Johor basin in Johor, Malaysia, an agriculture-dominated area. The present study analyses the modelling uncertainties arising from estimations of design flow, terrain data sets, geometric description in hydraulic models and different modeling approaches, and develops recommendations for practitioners. Explicit account for uncertainties and studying their impact in flood inundation mapping allow for more informed and effective decision making.
1.2 Problem statement
1.3 Flood mapping
1.4 Uncertainty in flood hazard mapping
1.5 Research questions
1.6 Aims and research objectives
1.7 Dissertation structure
2 Literature review
2.1 What is floods
2.2 Types of flood
2.3 Flood prone areas
2.4 Hazard and flood hazard
2.5 Flood modelling
2.6 Uncertainty in flood modelling and mapping
2.7 Flood mapping
3 Study area and data availability
3.1 Study area
3.2 Data Availability
4 1‐D hydraulic modelling: the role of cross‐sections spacing
4.3 Results and Discussion
4.4 Concluding remarks
5 2‐D hydraulic modelling: the role of digital elevation models
5.2 Differentiation of DEMs re‐sampling technique
5.3 Results and discussion
6 1‐D hydraulic modelling: the role of digital elevation models
6.2 Available data
6.4 Results and discussion
7 Uncertainty in simulating design flood profiles and inundation maps on the Johor River, Malaysia
7.3 Results and discussion
7.4 Conclusions Chapter
8 Conclusions and recommendations
IHE Delft PhD programme leads to a deepening of a field of specialisation. PhD fellows do scientific research, often with conclusions that directly influence their region. At IHE Delft, PhD researchers from around the world participate in problem-focused and solution-oriented research on development issues, resulting in an inspiring research environment. PhD fellows work together with other researchers from many countries dealing with topics related to water and the environment.
PhD research is often carried out in the ‘sandwich’ model. Preparation and final reporting – the first and last portion of the programme – are carried out in Delft, while actual research is done in the fellow’s home country, under co-supervision of a local institute. Regular contacts with the promotor are maintained through visits and long-distance communication. This enables researchers to employ solutions directly to problems in their geographical region.
IHE Delft PhD degrees are awarded jointly with a university. The degrees are highly valued and fully recognised in all parts of the world.