Mapping Water Availability Across Africa

Human-driven climate change is contributing to extreme weather events around the world, including a record-breaking multi-year drought in the eastern Horn of Africa that has affected the availability of water resources. To track water availability for livestock and agriculture across Africa, scientists with the Famine Early Warning Systems Network (FEWS NET) developed a Water Point Viewer that monitors 338 rangeland ponds from Senegal to Somalia. 

Rangelands are expansive areas of land covered by vegetation and native livestock. Pastoralists and agropastoralists depend on rangelands, including rangeland ponds, to feed and water their animals. In areas of Africa plagued by limited rainfall and arid conditions, rangeland ponds are vital sources of water.

Weendou Lamma Pond, Senegal. Credit: Kimberly Slinski, Assistant Research Scientist, University of Maryland

“Rangelands are characterized by limited and highly erratic rainfall and desiccating weather conditions, which makes pastoral livelihoods extremely vulnerable to climate shocks such as droughts and prone to food insecurity,” said Shraddhanand Shukla, Researcher for the University of California, Santa Barbara Climate Hazards Center. “In August 2023, USAID and FEWS NET projected that 65 million people in countries of sub-Saharan Africa with large rangelands areas required urgent food assistance.”

To help pastoralists and agropastoralists in countries including South Sudan, Nigeria, Ethiopia, and Somalia cope with drought-related detriments to rangeland water resources, FEWS NET and the U.S. Geological Survey launched the Earth Observation-Based Monitoring and Forecasting of Rangeland Water Resources project to help forecast water availability and inform humanitarian needs and pastoral adaptation.

Web interface for the existing FEWS NET Water Point Viewer showing water availability for November 15, 2023. The Water Point Viewer is being updated as part of the Earth Observation-Based Monitoring and Forecasting of Rangeland Water Resources project. Credit: FEWS NET

As part of this project, the team developed the Water Point Viewer, an interactive mapping tool that monitors and visualizes water points throughout arid and semi-arid regions in the Sahel and East Africa. These water points are placed within five distinct categorizations, each demonstrating long-term median water levels and the current conditions of water levels in relation to the long-term average. 

“Monitoring and forecasting rangeland water availability is of critical importance to food security early warning systems in Africa as populations relying on rangeland water resources often make up a substantial portion of people in need of emergency food assistance,” University of Maryland Earth System Science Interdisciplinary Center Assistant Research Scientist Kimberly Slinski said. “Early warning of rangeland water resources can lead to early warning of food insecurity in the population relying on those resources.”

The Water Point Viewer map provides historical data stretching as far back as the early 1980s, with each data point containing graphs that communicate fluctuations in preliminary depth, median depth, and final depth of water points. The data also take into account the correlation between changes in the median and final depth of water points and precipitation and water evaporation measured within the region. 

“In its existing form, the Water Point Viewer helps stakeholders understand the current availability of water for livestock and human use, which in turn informs food security analysis, humanitarian assistance planning, and a range of other activities,” Slinksi said. “[The Earth Observation-Based Monitoring and Forecasting of Rangeland Water Resources project] will significantly expand and improve the existing Water Point Viewer, increasing the locations monitored, developing new time series of water point surface area using high-resolution satellite data, and improving overall model physics. These developments will also lead to one of the most exciting contributions of this work: new predictive capabilities for forecasting water point stress.”

As climate change continues to impact precipitation patterns across the Sahel and East Africa, the Earth Observation-Based Monitoring and Forecasting of Rangeland Water Resources project will help governments, non-governmental organizations, and other key actors with food security analysis, humanitarian assistance planning, and other activities–thereby allowing them to take evidence-based actions to improve livelihoods and ultimately save lives. 

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Original article found at https://www.climatelinks.org/blog/mapping-water-availability-across-africa.