Department of Physical Geography The Zambezi River Basin: water resources management Energy-Food-Water nexus approach Gabriel Sainz Sanchez Master’s thesis NKA 216 Physical Geography and Quaternary Geology, 45 Credits 2018 Preface This Master’s thesis is Gabriel Sainz Sanchez’s degree project in Physical Geography and Quaternary Geology at the Department of Physical Geography, Stockholm University. The Master’s thesis comprises 45 credits (one and a half term of full-time studies). Supervisors have been Arvid Bring at the Department of Physical Geography, Stockholm University and Louise Croneborg-Jones, The World Bank. Examiner has been Steffen Holzkämper at the Department of Physical Geography, Stockholm University. The author is responsible for the contents of this thesis. Stockholm, 8 June 2018 Lars-Ove Westerberg Vice Director of studies Abstract The energy-food-water nexus is of fundamental significance in the goal towards sustainable development. The Zambezi River Basin, situated in southern Africa, currently offers vast water resources for social and economic development for the eight riparian countries that constitute the watershed. Hydropower generation and agriculture are the main water users in the watershed with great potential of expansion, plus urban water supply materialise the largest consumers of this resource. Climate and social changes are pressuring natural resources availability which might show severe alterations due to enhances in the variability of precipitation patterns. This study thus examines the present water resources in the transboundary basin and executes low and high case future climate change incited scenarios in order to estimate the possible availability of water for the period 2060-2099 by performing water balances. Along with projections of water accessibility, approximations on water demands from the main consumer sectors are performed. Results show an annual positive balance for both projected scenarios due to an increase in precipitation during the wet season. They also present a severe increase in overall temperature for the region contributing to a strong increase in evapotranspiration. Projections further inform of an acute increase in water demand for irrigation and urban supply, nevertheless, evaporation from hydropower storage reservoirs continues to exceed water withdrawals in volume. Acknowledging the uncertainty contained in this report allows a broader offer of recommendations to be considered when planning for future developments with a sustainable approach. Improvement of hydrological collection systems in the Zambezi basin is indispensable to accomplish a deeper and cohesive understanding of the watershed water resources. Cooperation and knowledge communication between riparian countries seems to be the right beginning towards social and economic sustainable development for the Zambezi River Basin. Key words: Zambezi River Basin; Water resources management; Climate change; Energy- Food-Water nexus; Future projections. Acknowledgements Thanks to the United States Geological Survey (USGS) for providing digital this study with elevation models of Africa. I would also like to thank GRDC for their contribution on stations discharge data as well as ARA-Zambeze (The Regional Administration of water of the Zambezi), Mozambique. Also, Louise Croneborg-Jones, from the World Bank, who suggested the study area for my research aim. Finally, my thesis supervisor, Arvid Bring, for providing me with ideas on how to execute my goals when options seemed vanished. Table of Contents 1. Introduction ................................................................................................................................... 4 1.1. Research questions .................................................................................................................. 6 2. Description of the Zambezi River Basin ..................................................................................... 6 2.1. Study area ................................................................................................................................ 6 2.2. Climate .................................................................................................................................... 8 2.3. Geomorphology ...................................................................................................................... 9 2.4. Land cover/ land use ............................................................................................................... 9 2.5. Climate change ........................................................................................................................ 9 2.6. Floods and droughts .............................................................................................................. 10 2.7. Groundwater resources ......................................................................................................... 10 2.8. Lack of agreement on sharing of water resources ................................................................. 10 2.9. Uncertainty ............................................................................................................................ 11 2.10. Demand sources .................................................................................................................... 11 2.10.1. Hydropower .................................................................................................................. 12 2.10.2. Agriculture .................................................................................................................... 13 2.10.3. Population ..................................................................................................................... 13 2.10.4. Environmental flows ..................................................................................................... 14 3. Methods ........................................................................................................................................ 15 3.1. Climate data .......................................................................................................................... 15 3.1.1. Historical ....................................................................................................................... 16 3.1.2. Projected RCP scenarios ............................................................................................... 16 3.2. Runoff data ............................................................................................................................ 17 3.3. Evapotranspiration ................................................................................................................ 18 3.4. Water consumption ............................................................................................................... 20 4. Results .......................................................................................................................................... 21 4.1. Water balance ........................................................................................................................ 21 4.2. Runoff data ............................................................................................................................ 26 4.3. Water demands ...................................................................................................................... 31 4.3.1. Hydropower evaporation ............................................................................................... 31 4.3.2. Irrigation ....................................................................................................................... 32 4.3.3. Domestic water supply .................................................................................................. 33 4.4. Scenario summary ................................................................................................................. 34 4.4.1. Historical 1950-1999..................................................................................................... 34 4.4.2. RCP 2.6 ......................................................................................................................... 34 4.4.3. RCP 8.5 ......................................................................................................................... 35 5. Discussion..................................................................................................................................... 36 2 5.1. Recommendations ................................................................................................................. 41 6. Conclusion ................................................................................................................................... 45 References ............................................................................................................................................ 46 Appendix ............................................................................................................................................... 50 Botswana ........................................................................................................................................... 50 Malawi .............................................................................................................................................. 51 Mozambique ....................................................................................................................................