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Drought can despair anyone whose livelihood depends on rain. Crops wither, along with the hope of an income for the year. In countries like Ethiopia, pastoralists’ nomadic search for grass and water becomes more desperate as their animals emaciate.

During dry years, there’s no guarantee that a pond or stream will contain water when the pastoralists arrive. The trek could end in frustration, heartbreak, and scattered animal carcasses.

The Horn of Africa, the large East African peninsula that includes Ethiopia and several other countries, is in the midst of a severe drought. Four consecutive rainfall seasons since 2020 have been below normal, including the March-to-May season that just ended. Agricultural families face drastic losses in income and an increased risk of malnutrition, while all citizens face rising prices and scarce food supplies. The result: a humanitarian crisis.

The Famine Early Warning Systems Network (FEWS NET), created and funded by the United States Agency for International Development (USAID), monitors conditions around the world and provides analysis about current and projected scarcity in the most food-insecure places. Remote sensing scientists and computer programmers at the U.S. Geological Survey (USGS) Earth Resources Observation and Science (EROS) Center contribute to FEWS NET reports with mapping, analysis, and monitoring tools.

Map of marked Ethiopian waterholes
This is Ethiopia's Water Point Viewer, with waterholes marked on the map and details about each listed on the right. (FEWS NET image)

Watching the Waterholes

One tool, called the Water Point Viewer, uses data from several satellites to model the water levels in 234 waterholes that stretch across central Africa from Senegal to Somalia—ponds that pastoralists rely on for their livestock. Ethiopia has found it so valuable it received help setting up a viewer customized for its country.

The Water Point Viewer lists the size, current depth percentage, and median depth percentage of each waterhole for historical perspective. Importantly, it also categorizes each waterhole as “Good,” “Watch,” “Alert,” “Near-dry,” and “Seasonally-dry.” This color-coded information reveals, at a glance, the condition of waterholes to inform government agencies and nonprofit organizations and to guide pastoralists.

Some of the waterholes are natural depressions or modified natural depressions. “They don’t hold a lot of water. Some of them disappear during the dry season,” said Dr. Gabriel Senay, a USGS research physical scientist on the FEWS NET team. “So, what we’re doing is trying to monitor the level of the water. It’s really about knowing whether the waterhole is drying up and how fast it’s drying up compared to an average year. That’s the information we provide on a daily basis.”

Project for Scientists and Programmers

One key goal of FEWS NET is to build capacity in institutions, such as government agencies, in food-insecure countries. So, when the Ethiopian Ministry of Agriculture desired its own water point viewer, a team of scientists and computer programmers with EROS FEWS NET went to work.

“The science is mainly in the development of the model based on hydrologic principles,” Senay said. The water point model’s data inputs include satellite rainfall estimates, evapotranspiration, digital elevation, run-off estimates, and location and surface area via satellite sensors such as Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) and Landsat.  

“But you need to implement them in a computer code, a language. That’s where computer programmers come in, writing physics equations in a computer language and producing useful products,” Senay added.

The code sets up the Water Point Viewer across Africa and draws on a database to produce a rolling median that’s continually updated, according to EROS contractor Max McElhone, a software engineer. With that, the viewer generates tables, charts, and downloadable data.

Chart laid on top of a map
This chart gives historical context for one particular waterhole in Ethiopia in the Water Point Viewer. (FEWS NET image)

EROS gave the Ethiopian Ministry of Agriculture the code to create their own focused water point website. Then, McElhone said, “they went through and generated the data for the areas that they were interested in.”

Virtual Implementation

Generally, a technology transfer like this would see EROS providing at least a couple days of in-person training and workshops, Senay said. For example, an agreement to share irrigation mapping and water consumption modeling technology with Brazil’s National Water Agency involved hands-on training, visits to EROS, and webinars.

However, the Ethiopia effort coincided with the COVID-19 pandemic. Someone who had helped with fieldwork to set up the initial Water Point Viewer project in about 2006 remembered it when, as part of The Alliance of Biodiversity International and CIAT (International Center for Tropical Agriculture), he began working with the Ethiopian Ministry of Agriculture.

The FEWS NET team started with a webinar explaining water points and the program’s implementation and then shared the technology, which also involved many email exchanges with the programmers.

“I’m very impressed that it was pretty straightforward for them to implement the transfer of technology on their servers,” said Jim Rowland, a USGS physical geographer at EROS who has worked with FEWS NET for many years.

“It was good to work with them,” said Claudia Young, a software engineer contractor at EROS who serves as a task lead for FEWS NET. “We communicated with each other very well.”

Ultimately, it achieved the FEWS NET goal to help an institution increase its capabilities.

“We want to implement this in the country so that they will have the flexibility to improve and to expand, just customize it to their needs,” Senay said. “All of the efforts we’ve been putting in for years are not only to create graphics but are being advanced by others—being an innovative solution to address a local problem. It’s very satisfying.”

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