Presenting the hydrological research carried out in the Migina catchment (260 km2), Southern Rwanda with the objective to explore the hydrological trends and climate linkages for catchments in Rwanda (26,338 km2), and to contribute to the understanding of dominant hydrological process interactions. Different Hydro-meteorological instrumentations have been installed for several months in the Migina catchment and measurements have been carried out. The trend analysis is based on Mann-Kendall (MK) test and Pettitt test on times series data varying from 30 to 56 years before 2000. The hydrometric data and modern tracer methods is used for hydrograph separation and show that subsurface runoff is dominating the total discharge even during rainy seasons at Cyihene-Kansi and Migina sub-catchments, respectively. Further, a semi-distributed conceptual hydrological model HEC-HMS is applied for assessing the spatio-temporal variation of water resources in the Migina catchment. The model results are compared with tracer based hydrograph separation results in terms of the runoff components. The model performed reasonably well in simulating the total flow volume, peak flow and timing as well as the portion of direct runoff and baseflow.
CHAPTER 1 INTRODUCTION
1.2. Water resources in Rwanda
1.3. Hydroclimatic data availability in Rwanda
1.4. Data collection and management in Rwanda
1.5. Data reporting and sharing systems
1.6. Space-time variation of hydrological process
1.7. Hydrological modelling
1.8. Problem statement and objectives
1.9. Thesis outline
CHAPTER 2 METHODS AND MATERIALS
2.2. Study area
CHAPTER 3 STREAMFLOW TRENDS AND CLIMATE LINKAGES
3.2. Data and methods
3.4. Discussion of results
CHAPTER 4 IDENTIFICATION OF RUNOFF GENERATION PROCESSES USING HYDROMETRIC AND TRACER METHODS
4.2 Data and methods
CHAPTER 5 PREDICTION OF RIVER PEAK DISCHARGE IN AN AGRICULTURAL CATCHMENT IN RWANDA
5.2. Data collection and processing techniques
5.3. Results and discussions
5.4. Concluding remarks
CHAPTER 6 ASSESSMENT OF WATER RESOURCES AVAILABILITY IN A MESO-SCALE CATCHMENT USING CATCHMENT MODELLING AND THE RESULTS OF TRACER STUDIES
6.2. Data and methods
6.3. Results and discussions
6.4. Concluding remarks
CHAPTER 7 CONCLUSIONS AND RECOMMENDATIONS
7.1. Summary of the main conclusions
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.