Feed the Future
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Finding the Ephemeral: Satellite Data Guide Pastoralists to Water

This post was written By Abdoul Aziz Boubacar Mainassara, Communications Lead, SERVIR-West Africa/AGRHYMET

The Ferlo region of north-central Senegal is a vast expanse of dry savannah covering over a third of the country’s total area. With only a few small, scattered settlements, this region is almost exclusively reserved for pastoralism, both by tradition and government policy. Inhabited primarily by the Serer and Fulani peoples, the region is characterized by an extremely dry climate with a long dry season – up to nine months of the year – making living conditions very difficult.

During the rainy season from July to September, water and forage are fairly abundant for livestock. But during the dry season that extends through June, pastoralists rely on ephemeral water bodies – temporary ponds that hold remnants of water left over from the rainy season – to sustain their animals. In the past, local populations could rely on historical knowledge, passed on from generation to generation, to find these watering holes during the dry season. However, changing weather patterns have made the historical knowledge less reliable, requiring a different approach.

A screenshot of the ephemeral water body service dashboard. Red indicates <25% water coverage in this waterhole, indicating a drying source of water.  

After multiple consultations with key stakeholders*, the SERVIR-West Africa consortium partner, Senegal-based Centre de Suivi Ecologique (CSE), and Dr. Niall Hanan, NASA Applied Sciences Team partner, developed an innovative solution to help address this problem. Using free and open source satellite imagery from NASA’s Landsat suite and the European Space Agency’s Sentinel-2, SERVIR launched a new service that provides accurate and timely information concerning the availability of water in all parts of the Ferlo throughout the dry season.

This service monitors the location of watering holes and produces high-resolution maps with sufficient accuracy to assist local authorities with decision-making on natural resource management. The forecasts generated by this system will be disseminated directly to affected populations through cell phone text messages and local radio broadcasts.

“As a result of their importance in the life of pastoralists, ponds that retain water for a quite long time (5-6 months) all bear a name and are known by most pastoralists who move locations based on the change of seasons. Having reliable information to better manage them would be of great help to us,” notes Demba BA, President, Entente des Groupements Associés pour le développement à la Base (EGAB).

Pastoralists receiving information on the location of ephemeral
water bodies during the dry season in the Ferlo.
Photo credit: USAID/West Africa  

SERVIR-West Africa and its consortium partners will continue to work with local stakeholders and beneficiaries to improve the accuracy and availability of this service to strengthen the resilience of agropastoral systems in response to regional climate change. This service is a great example of how SERVIR connects space to village with an innovative solution that addresses a critical water resource challenge, thereby improving livelihoods and fostering self-reliance.

*Stakeholder consultations and needs assessments are part of SERVIR's approach to designing user-focused geospatial information services. For more on this approach, see the Service Planning Toolkit: https://www.servirglobal.net/about-Servir

This figure shows where the research in today's post contributes to the Feed the Future Results Framework