In a first regional study, the Water Futures and Solutions Initiative (WFaS) focused on East Africa with the extended Lake Victoria Basin (eLVB) as a key research area, aiming to understand the future water balance in the region toward 2050. The eLVB is part of the African Great Lakes region and covers the up-stream hydrological watershed of the river Nile when it exits Uganda and flows into South Sudan. It covers an area of 464 thousand km2 and is home to more than 70 million people today.
The team used an integrated modelling framework combining the IIASA Community Water Model (CWATM) and the Hydroeconomic Optimization model (ECHO), under two future development scenarios. Based on the East Africa Vision 2050 and the development visions of the East Africa Community member countries, the team developed an East Africa Regional Vision Scenario, while the second scenario, Business As Usual, is based on the Shared Socioeconomic Pathways (SSP2). Two stakeholder workshops helped to deepen the understanding and refine socio-economic and bio-physical drivers (first workshop) which were further used to set modelling parameters and also to verify and discuss the modelling results (second workshop).
Our key results:
A doubling of population in the eLVB combined with strong economic development by 2050 will lead to a high increase in water demand. Depending on scenario, the growth is most pronounced for expanding irrigation and supplying domestic water. Climate change is characterized by increasing temperatures combined with higher precipitation variability, i.e. there is a tendency that rainy seasons become wetter and dry season dryer. Land use changes offset largely the effect of higher evapo-transpiration due to increasing temperature leading to lower runoff. The storage effects of large water bodies in the basin lead to considerable delay in the response time of river discharge. The combination of all development trends of the eLVB water system indicates that despite the increasing water demand, the changes in the discharge and flow regime of the Nile will be small.
The results of the two scenarios show more moderate water scarcity when measured using the Water Exploitation Index (ratio of water resources and demand) compared to water scarcity when measured using the Water Crowding Index (per capita water resources). This points to a high degree of ‘economic water scarcity’ in the eLVB because the regionally estimated water demand is apparently lower than the globally unified ‘entitlement’ of a per capita indicator of water resources only. However, there is a high spatial variability in water scarcity development trends, which are most pronounced in the Kagera, Mara and Simiyu sub-watersheds. Figures 1 & 2 below.
Water Scarcity Atlas:
Our results are also shown on the Water Scarcity Atlas which is developed and maintained by the Water & Development Research Group at Aalto University, Finland, in collaboration with the Water Program at IIASA.
The Water Scarcity Atlas provides an introduction to water scarcity, and showcases analyses that cover the whole world.
For Global results please have a look at:
Our East Africa results on water shortage, water stress and water scarcity are on:
The project is funded by the Austrian Development Agency (ADA) and the Austrian Federal Ministry of Sustainability and Tourism. The results are helping the Lake Victoria Basin Commission and its member states (Burundi, Kenya, Rwanda, South Sudan, Tanzania, and Uganda) to make science based water resource management decisions. Stakeholder workshops attracted researchers and practitioners from across the region. In December 2018, the results were also presented and discussed at a workshop that included training participants on the analysis and interpretation of the modelling results.
The team will expand their work through a project titled, Scaling out Resilient Water and Agricultural Systems (scaleWAYS), which looks at up-scaling options for water and land management practices for the resilient and sustainable intensification of agricultural production and food systems in the extended Lake Victoria Basin. (Link to scaleWAYS).
Figure 1: Change of the Water Exploitation Index for the Lake Victoria Basin from 2010 to 2050. The panels indicate how total water abstraction puts pressure on water resources. Severe water stress can occur in regions with an index over 40%.
Figure 2: Change of the Water Crowding Index for the extended Lake Victoria Basin from 2010 to 2050. Below 1,700m³/capita/year water stress appears regularly, below 1,000 water scarcity is a limitation to economic development and human health, and below 500 water availability is a main constraint to life.
About IIASA Water Futures and Solutions Initiative (WFaS)
The IIASA Water Futures and Solutions Initiative (WFaS) identifies and tests solution pathways across different economic sectors and supports the co-design of future development scenarios and possible solution options through stakeholder engagement. This provides important input for supporting mid- to long-term water management and planning based on informed decision making. This helps to balance supply and demand for all water users across different economic sectors for current and future generations while safeguarding the environment. IIASA research supports the incorporation of water science into policy, planning, and applied management issues.
Last edited: 11 December 2020
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