1 Answer | Add Yours
Most rivers are sustained by both groundwater and runoff. Surface runoff is a major contributor after a rain, but runoff also can result from snow or ice melting, which can last through much of the summer at high altitudes. Additionally, some runoff may be captured and retained for a time by wetlands or impoundment areas, and may feed the river's flow for some period of time after the last precipitation has fallen.
Groundwater will continue to sustain a stream's flow even when there is no precipitation. Water contained in an aquifer can flow to the surface as a spring or seep, or can fill a lake or river basin from beneath. Aquifers occur wherever geological conditions are right, and an aquifer can be the headwaters of a river.
We’ve answered 288,398 questions. We can answer yours, too.Ask a question