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.
Peak water flows in parts of India's largest river basin have been falling by more than one-sixth every decade, according to a study published in npj Natural Hazards that highlights a similar trend across the country, impacting ...
Earth Sciences
Jul 7, 2025
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Atmospheric rivers are responsible for most flooding on the West Coast of the U.S., but they also bring much-needed moisture to the region. The size of these storms doesn't always translate to flood risk, however, as other ...
Environment
Jun 12, 2025
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California's Central Valley—one of the nation's most critical agricultural regions and home to over 1.3 million people—is prone to flooding. Mapping the extent of winter floods has been challenging for experts, however, because ...
Earth Sciences
Jun 11, 2025
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A study in the International Journal of Environment and Waste Management has found a direct link between Ghana's mounting urban flooding challenges and unregulated waste disposal practices. The findings have significant consequences ...
Environment
Jun 10, 2025
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The 120-mile Tijuana River flows from Baja California into the United States and discharges millions of gallons of wastewater—including sewage, industrial waste and runoff—into the Pacific Ocean every day, making it the dominant ...
Earth Sciences
May 28, 2025
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Gully erosion is the most severe form of soil erosion, and it can seriously impact agricultural fields, contributing to sediment loss and severe nutrient runoff into waterways. Gullies can be triggered suddenly by a single ...
Earth Sciences
May 21, 2025
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A new study from North Carolina State University researchers finds that conversion of forests to urban development or agriculture near streams can have harmful effects on water quality downstream, presenting both health concerns ...
Environment
May 6, 2025
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Growing communities and extensive agriculture throughout the Western United States rely on meltwater that spills out of snow-capped mountains every spring. The models for predicting the amount of this streamflow available ...
Earth Sciences
May 5, 2025
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119
Green spaces play an important role for urban populations, whether by protecting against extreme weather events or providing space for recreation. In two studies, researchers at the Karlsruhe Institute of Technology (KIT) ...
Environment
Apr 29, 2025
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115
Rapid urbanization and climate change are intensifying urban flash floods and waterlogging, especially in coastal cities. In a new study published in Risk Sciences, a duo of researchers explore the growing challenges and ...
Environment
Apr 28, 2025
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