Baseline Study for the Basin of Lake Kivu and the Ruzizi River
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LAKE KIVU AND RUZIZI RIVER BASIN AUTORITHY (ABAKIR) REFERENCE: 20.214.5-022.00 BASELINE STUDY FOR THE BASIN OF LAKE KIVU AND THE RUZIZI RIVER REPORT DECEMBER 2020 Identification sheet Countries Rwanda, Burundi, DRC Funder Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) Project Baseline study of the Lake Kivu and Ruzizi River basin Study Baseline study Document Baseline study report on the Basin Date December 2020 Consultant SHER Consult Ltd SHER Consult Ltd Coordination M. Goffin Rue de l'Akagera - KN 16 Ave #65 Reference : SCR16 Nyarugenge - Kigali / B.P. 1526, Kigali Phone : +250 782 521 410 Rwanda E-mail : [email protected] Tel. : +250 788 304 364 www.sherconsult.com Rev. n° Date Content Prepared by: Verified by: Work package 1 and J. Derouane, Q. Goor, A. 0 11/2020 M. Goffin Work package 2 Linel, F. Kayigamba Work package 1 and J. Derouane, Q. Goor, A. 1 12/2020 M. Goffin Work package 2 Linel, F. Kayigamba Work package 1 and J. Derouane, Q. Goor, A. 2 12/2020 M. Goffin Work package 2 Linel, F. Kayigamba SHER Consult Ltd Baseline study of the Lake Kivu basin and the Ruzizi River basin 12/2020 Table of Contents Executive Summary ......................................................................................................... xvi Context of the study ................................................................................................... 1 Objectives of the study and expected results ............................................................... 1 Definition of the study area ........................................................................................ 2 Methodology ............................................................................................................. 2 Administrative and socio-economic context ................................................................ 5 5.1. Administrative framework ............................................................................................. 5 5.2. Demography .................................................................................................................. 6 Current population of the basin (2020) ................................................................................... 6 Projections of population growth up to 2050 .......................................................................... 6 5.3. Level of socio-economic development of the basin ......................................................... 7 Situation in Burundi ................................................................................................................ 7 Situation in the DRC ................................................................................................................ 8 Situation in Rwanda ................................................................................................................ 8 5.4. Food security situation................................................................................................... 9 Situation in Burundi ................................................................................................................ 9 Situation in the DRC .............................................................................................................. 10 Situation in Rwanda .............................................................................................................. 10 Physical environment ............................................................................................... 11 6.1. Topography and geomorphology .................................................................................. 11 6.2. Soil Types .................................................................................................................... 12 6.3. Geological context ....................................................................................................... 13 Climate context ........................................................................................................ 15 7.1. Current climate context ............................................................................................... 15 Precipitation .......................................................................................................................... 15 Temperature .......................................................................................................................... 16 Evapotranspiration ................................................................................................................ 16 7.2. Climate change ............................................................................................................ 17 Water resources ....................................................................................................... 18 8.1. Catchment areas and surface waters ............................................................................ 18 Watersheds and sub-basins ................................................................................................... 18 Lake Kivu and its tributaries .................................................................................................. 19 The Ruzizi river and its tributaries ......................................................................................... 22 8.2. Ground water .............................................................................................................. 23 Types of aquifers ................................................................................................................... 23 Aquifer potential ................................................................................................................... 24 Groundwater exploitation ..................................................................................................... 24 Land use and evolution ............................................................................................ 25 SCR16 SHER Consult Ltd i Baseline study of the Lake Kivu basin and the Ruzizi River basin 12/2020 9.1. Current land use .......................................................................................................... 25 9.2. Previous land use ......................................................................................................... 27 9.3. Deforestation and extension of agricultural areas ......................................................... 28 9.4. Extension of urban areas .............................................................................................. 28 Water Use ................................................................................................................ 29 10.1. Introduction: NEXUS Water-Energy-Food (WEF) approach ......................................... 29 10.2. Drinking water supply .............................................................................................. 30 10.3. Agricultural water .................................................................................................... 32 Rain-fed agriculture on the slopes ......................................................................................... 32 Irrigated agriculture in the Ruzizi plain .................................................................................. 33 10.4. Hydroelectricity ....................................................................................................... 38 10.5. Gas extraction in Lake Kivu ....................................................................................... 40 10.6. Oil extraction ........................................................................................................... 41 10.7. Animal husbandry .................................................................................................... 41 10.8. Fish farming and fishing ........................................................................................... 42 10.9. Industries................................................................................................................. 43 10.10. Mines ...................................................................................................................... 45 10.11. Navigation ............................................................................................................... 45 10.12. Tourism.................................................................................................................... 46 10.13. Summary of the WEF NEXUS uses and water demand ............................................... 47 Water balance ......................................................................................................... 47 11.1. Overview of the balance sheet methodology ............................................................ 47 11.2. Summary of the water balance results ...................................................................... 50 11.3. Conclusions of the water balance: adequacy between water availability and water needs of the basin .................................................................................................................. 52 Environmental situation ........................................................................................... 52 12.1. Soil degradation ....................................................................................................... 52 Estimating soil losses: RUSLE model ...................................................................................... 53 Anti-erosion