1st Edition

Understanding Hydrological Processes in an Ungauged Catchment in sub-Saharan Africa UNESCO-IHE PhD Thesis

By Marloes Mul Copyright 2009
    144 Pages 40 Color Illustrations
    by CRC Press

    144 Pages
    by CRC Press

    Ungauged catchments can be found in many parts of the world, but particularly in sub-Saharan Africa. Information collected in a gauged catchment and its regionalisation to ungauged areas is crucial for water resources assessment. Especially farmers in semi-arid zones are in need of such information. Inter and Intra-seasonal rainfall variability is large in these areas, and farmers depend more and more on additional surface and groundwater resources for their crop production. As a result, understanding the key-hydrological processes, and determination of the frequencies and magnitudes of stream flows, is very important for local food production. This is particularly true for the ungauged Makanya catchment in Tanzania, which is the subject of this study.

    Abstract
    Acknowledgement 
    Preface
    List of Symbols
    List of Acronyms

    Chapter 1 Introduction 
    1.1 Background                                                                                     
    1.2 Impact of Land Use and Management                                                   
    1.3 Hydrological Process Understanding                                                     
    1.4 Hydrological Modelling                                                                     
    1.5 Objectives                                                                                      

    Chapter 2 Study Area 11
    2.1 Pangani River Basin                                                                         
    2.2 South Pare Mountains                                                                    
    2.2.1 Geology
    2.2.2 Rainfall
    2.2.3 Agricultural water use
    2.2.4 Runoff

    Chapter 3 Weather and Climate
    3.1 Rainfall                                                                                         
    3.2 Spatial Rainfall Variability                                                                
    3.3 Potential Evaporation                                                                       
    3.4 Potential Transpiration versus Rainfall                                                 

    Chapter 4 Investigation of Flow Systems 
    4.1 Hydrochemical Mapping                                                                    
    4.1.1 Water Quality of Springs
    4.1.2 Comparison of Dry versus Wet Conditions
    4.2 Geophysical Investigations                                                                 
    4.2.1 Site I: Highlands
    4.2.2 Site II: Kilenga Spring
    4.2.3 Site III: Valley Cross Section
    4.2.4 Site IV: Stream Bed
    4.2.5 Auger Wells
    4.3 Spring Types                                                                                 
    4.4 Synthesis: Groundwater Flow Systems in the Makanya Catchment            
    4.5 Base flow fluctuations                                                                      
    4.5.1 Observations
    4.6 Conclusion                                                                                    

    Chapter 5 Investigation of Hydrological Events 
    5.1 Hydrograph Separation using Hydrochemical Tracers                              
    5.1.1 9 November Event
    5.1.2 5 December Event
    5.1.3 Discussion
    5.2 Spatial Rainfall Variability and Runoff Response during an Extreme Event 
    5.2.1 Rainfall
    5.2.2 Runoff
    5.2.3 Water Quality
    5.2.4 Conclusions

    Chapter 6 Hydrological Modelling
    6.1 Observations                                                                                   
    6.2 Methodology                                                                                  
    6.3 Model Description                                                                           
    6.4 Optimisation                                                                                  
    6.5 Results                                                                                         
    6.6 Conclusions                                                                                   

    Chapter 7 Sharing Water
    7.1 Water Allocation Practices                                                                
    7.2 agricultural Water Users in Makanya Catchment                                   
    7.2.1 Manoo Furrow System
    7.2.2 Makanya Spate irrigation System
    7.3 Water Sharing between Users of Adjacent Furrows                              
    7.4 Water Allocation between Neighbouring Villages                                 
    7.4.1 Agreement between Ndolwa and Bangalala
    7.4.2 Agreement between Vudee and Bangalala
    7.5 Water Sharing between Distant Villages                                             
    7.6 Discussion and Concluding Remarks                                                 

    Chapter 8 Syntheses and Conclusions 
    8.1 Farming Adaptation to Climatological, Hydrological and Bio physical Constraints                                                                                          1
    8.2 Hydrological Process Understanding and Modelling                              
    8.3 Impact of farming activities on hydrology                                         

    References 
    Samenvatting 
    About the Author  

    Biography

    Marloes Mul received her MSc in Civil Engineering from Delft University in 2007. Between 2004 and 2007 she worked in Africa (Zimbabwe, Tanzania) on her PhD for UNESCO-IHE. As of January 2008 Marloes returned to UNESCO-IHE in The Netherlands as lecturer Water Resources Management, where she is now coordinating the MSc programme Water Management.