Runoff, in the context of environmental and Earth system topics, refers to the portion of precipitation, snowmelt, or irrigation water that does not infiltrate into the soil or evaporate but instead flows over the land surface or through shallow subsurface pathways to streams, rivers, lakes, or coastal waters. It is a central component of the hydrological cycle, governed by factors such as soil permeability, land cover, topography, antecedent moisture, and rainfall intensity. Runoff mediates fluxes of sediments, nutrients, pollutants, and dissolved organic and inorganic constituents, strongly influencing watershed biogeochemistry, aquatic ecosystem function, flood regimes, and water resource availability.
Rowers on the River Po in Turin are battling vast blooms of algae, as high temperatures in northwest Italy and runoff from farms create ideal conditions for rampant plant growth.
Environment
Jul 16, 2026
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Warm, sticky nights are becoming increasingly common in the UK.
Environment
Jul 16, 2026
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After hours of torrential overnight rain lashed Lagos recently, church pastor Samuel Akpan spent most of the next day bailing water from his flooded parsonage in an upscale district of Nigeria's commercial capital.
Environment
Jul 16, 2026
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5
Heavy precipitation becomes more intense with every degree Earth warms. This affects flooding. Using hourly data from 384 rivers in the Alps, researchers from the WSL Institute for Snow and Avalanche Research SLF modeled ...
Earth Sciences
Jul 16, 2026
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7
A new study finds a widely used technique for assessing the health of freshwater streams is not effective at detecting a range of water quality problems, including those related to acidity, oxygen levels and the presence ...
Environment
Jul 13, 2026
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9
Across a narrow watershed in Asakura, a rural city in Fukuoka Prefecture, centuries-old stone channels still guide water through fields and into the river below. Today, those same systems are the focus of researchers at Kyushu ...
Environment
Jul 11, 2026
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12
Florida International University scientists have, for the first time, detected a toxic tire-derived chemical in Florida waterways and developed a new testing method that makes it easier to find and monitor the pollutant at ...
Environment
Jun 24, 2026
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7
Researchers at the University of Tsukuba have discovered that rainwater runoff in the highly rugged sedimentary rock mountains of Japan's Southern Alps is governed by two processes: "deep infiltration" and "shallow drainage ...
Earth Sciences
Jun 18, 2026
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6
Rainfall history is just as critical to predicting air pollution as where the air came from, a team led by University of Michigan Engineering researchers, in collaboration with scientists at the Appalachian Mountain Club ...
Earth Sciences
Jun 17, 2026
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33
While Reno families were celebrating the 1997 New Year, the Truckee River was surging into the city's downtown streets. A rainstorm was falling on the Sierra Nevada's deep snowpack, melting it rapidly and creating a hazardous ...
Earth Sciences
Jun 16, 2026
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11
