Jean-Paul Deroin has spent years watching water behave unpredictably in the vast, sun-baked depressions of North Africa’s Zone of Chotts. His team’s latest work, published in *GeoHazards* under the title “Mapping Flood in Endorheic Depressions Using Multitemporal and Multiresolution Remote Sensing Data,” turns satellite eyes on two of the region’s most dynamic salt lakes—Chotts Merouane and Melrhir—where water isn’t just a resource, but a recurring risk.
“These aren’t just puddles,” Deroin says from his lab in Reims. “They’re barometers of climate and consequence. What happens here ripples through agriculture, urban planning, and even energy infrastructure.”
For decades, the Chotts have oscillated between flood and drought, their cycles shaped by erratic rainfall and human intervention. But something has shifted. Chott Melrhir, once prone to dramatic inundations that drowned farmland and paralyzed cities like Biskra, has seen no major flooding since 2020. “That’s not normal,” Deroin notes. “It aligns with a steady decline in precipitation since the 1980s. Less water in, less water out—but also less dilution of salts, which means creeping soil degradation.”
It’s a slow-moving crisis with fast-moving implications. Salt buildup doesn’t just hurt date palms—it corrodes pipelines, clogs irrigation canals, and threatens desalination plants that energy operators rely on for cooling and process water. Algeria’s energy sector, particularly its sprawling oil and gas facilities in the Sahara, depends on stable water access. When seasonal floods fail to flush the system, salinity rises. When they do come—suddenly, intensely—they can overwhelm drainage networks, flooding substations or blocking access roads to remote rigs.
Chott Merouane tells a different story. Here, water flows almost year-round—not from the sky, but from treated wastewater and agricultural runoff via the Oued Righ. “Human activity has rewritten the hydrology,” Deroin explains. “We’ve turned a seasonal floodplain into a perennial wetland. That’s good for some crops, but it masks a growing vulnerability: aging drainage infrastructure can’t handle sudden storms anymore.”
The research leverages a powerful trio of eyes in the sky—Sentinel-2, MODIS, and Landsat—to stitch together a 60-year hydrological timeline. By layering high-resolution optical data with thermal and radar signals, Deroin’s team can now detect flood onset within days and track salt crust formation over seasons. “We’re not just mapping water,” he says. “We’re mapping risk—where it’s rising, where it’s falling, and where it’s hiding in plain sight.”
For energy companies operating in arid basins, the implications are clear: flood risk isn’t just about water levels anymore. It’s about salinity, infrastructure resilience, and long-term water security. A drier Chott Melrhir might reduce immediate flood damage, but it accelerates land degradation and increases the need for water treatment. Meanwhile, Merouane’s engineered wetlands could become unintended drainage basins during extreme events.
The study suggests a future where remote sensing isn’t optional—it’s operational. Energy planners could use these maps to site facilities away from flood corridors, design corrosion-resistant pipelines, or preemptively upgrade drainage systems in high-risk zones. “We’re moving from reactive crisis management to proactive adaptation,” Deroin observes. “That’s not just smart science. It’s smart business.”
As climate patterns continue to shift, the Chotts remain a living laboratory—and a cautionary tale. The same satellites that once tracked oil spills are now tracking salt. The same data that protects oases may soon protect power plants. And the same story unfolding in Algeria is being written, in different forms, across the world’s endorheic basins.