For thousands of years, the people living around Lake Chad have adapted their livelihoods to the rhythm of the annual flood. The coastlines of Lake Chad naturally shift inward and outward each year; the lake level rises in the rainy season, then recedes during the dry season. The communities are well-adapted to cope with the changes, overlapping farming with fishing and cattle-raising.
Lake Chad is the main source of food security and livelihoods in the region, however, a number of risks, including climate change, variability, and aquifer contamination, are threatening the Lake’s socio-ecological system and public health. With a low human development index in the region, lack of access to basic water and sanitation services, and one of the highest population growth rates in the world, investments in development projects are sorely needed. To design sustainable and climate resilient projects, adequate knowledge is needed about the water resources dynamics and how these will be affected by proposed projects.
“While rainfall-runoff models, lake models, and groundwater models exist separately, no integrative understanding of the dynamics between surface water, groundwater and abstractions exist,” said Aleix Serrat Capdevila, Senior Water Resources Specialist at the World Bank. “Thus, there is no understanding of how a sustainable or a “balanced” basin would be in terms of abstractions and their sustainability.”
As a result, to consolidate existing knowledge and build a common understanding of hydrologic dynamics of water resources, a World Bank team and the Lake Chad Basin Commission (LCBC), with the support of the Cooperation in International Waters in Africa (CIWA) program, are collaborating with United Nations Educational, Scientific and Cultural Organisation (UNESCO) and a broad range of partners – the German Federal Institute for Geosciences and Natural Resources (BRG), Bureau de recherches géologiques et minières (BRGM), ResEau, Sahara and Sahel Observatory (OSS), Permanent Interstate Committee for Drought control in the Sahel (AGRHYMET), and member state agencies. A workshop in May 2017 with partner organizations set in motion the collaborative process and consolidated a working group to create updated groundwater and surface water models which will ‘talk’ to each other.
“There are several organizations doing a lot of work, collecting data on surface water or groundwater, or operating in particular regions within the basin,” said Serrat Capdevila. “We thought ‘let’s bring all these pieces of the puzzle together to understand better the system as a whole’”
There are several CIWA-funded efforts being led to collect this data, including the development of an updated groundwater model of the Lake Chad Basin that integrates all the existing data and knowledge. In addition, the Remote Sensing Initiative of the Global Water Security and Sanitation Partnership (GWSP), is also supporting these CIWA-funded efforts by leveraging the power of satellites to monitor surface water dynamics. With real-time satellite rainfall estimates, weather predictions, seasonal forecasts, and a hydrologic model, water resources are monitored and hydrologic predictions are displayed through a user-friendly interface: The Lake Chad Flood and Drought Monitor.
The development of linked surface and groundwater modeling systems, with data from multiple organizations, will help establish a foundation to inform the good management of the Lake Chad basin’s water. This system, transparent and collaboratively developed, will let decision-makers assess the impacts of potential future projects and investments as well as their sustainability and resilience under different climate scenarios. In other words, it can inform a common view of what a sustainable, balanced basin would be in terms of abstractions from surface and groundwater for development purposes.
Monitoring water resources is essential to better inform development decisions because you need to know what you have in order to manage it well. Strong and informed water management at the basin scale will ensure the shared water resources of Lake Chad can be utilized to alleviate poverty while also protecting and preserving them.