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.
Tile drainage is a common practice used in agricultural fields to remove excess water, but it also transports harmful nutrients into water bodies, contributing to algal blooms that deprive aquatic life of oxygen. Woodchip ...
Biotechnology
Aug 11, 2025
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Just recently, the world watched as many people were injured and dozens died after a torrential flood swept through a Texas town early in July.
Environment
Jul 28, 2025
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It wasn't just data from maps, machines and rainfall readings that led CSIRO scientists to build Australia's most comprehensive and accurate flood model for the Richmond River catchment.
Environment
Jul 17, 2025
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In an analysis of the best available Earth systems models, Northeastern researchers found that by the turn of the next century, 850 million people will feel the effects of declining runoff from the world's major rivers.
Environment
Jul 16, 2025
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A new study from UNC-Chapel Hill reveals that repetitive flooding in North Carolina is far more common and more widespread than previously recognized, with over 20,000 buildings flooding multiple times between 1996 and 2020.
Earth Sciences
Jul 14, 2025
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For nearly a month, hundreds of thousands of Iowans have not been allowed to water their lawns—even though there's no drought.
Environment
Jul 11, 2025
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Texas Hill Country is known for its landscapes, where shallow rivers wind among hills and through rugged valleys. That geography also makes it one of the deadliest places in the U.S. for flash flooding.
Environment
Jul 7, 2025
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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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36
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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40
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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