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An open lake is a lake where water constantly flows out under almost all climatic circumstances. Because water does not remain in an open lake for any length of time, dissolved solids do not accumulate, and such lakes are usually fresh water. Open lakes form in areas where precipitation is greater than evaporation. Because most of the world's ...
A subterranean river (also known as an underground river) is a river or watercourse that runs wholly or partly beneath the ground, one where the riverbed does not represent the surface of the Earth. It is distinct from an aquifer , which may flow like a river but is contained within a permeable layer of rock or other unconsolidated materials.
The headwaters of a river are the smaller streams that feed a river, and make up the river's source. [4] These streams may be small and flow rapidly down the sides of mountains . [ 5 ] All of the land uphill of a river that feeds it with water in this way is in that river's drainage basin or watershed. [ 4 ]
In situ gold-bearing vein (in brown) at the Toi gold mine, Japan. In many gold mines exploited during the gold rushes of the 19th century, vein material alone was typically sought as ore material. [8] In most of today's mines, ore material is primarily composed of the veins and some component of the wall rocks which surrounds the veins. [9]
The total volume of water in rivers is estimated at 2,120 km 3 (510 cu mi), or 0.49% of the surface fresh water on Earth. [2] Rivers and basins are often compared not according to their static volume, but to their flow of water, or surface run off. The distribution of river runoff across the Earth's surface is very uneven.
A plan and side view of a generic, empty canal lock. A lock chamber separated from the rest of the canal by an upper pair and a lower pair of mitre gates.The gates in each pair close against each other at an 18° angle to approximate an arch against the water pressure on the "upstream" side of the gates when the water level on the "downstream" side is lower.
For details of rivers of the United Kingdom, see List of rivers of England; List of rivers of Scotland; List of rivers of Wales; Northern Ireland: see List of rivers of Ireland and Rivers of Ireland; Longest rivers of the United Kingdom
A bedrock river is a river that has little to no alluvium mantling the bedrock over which it flows. However, most bedrock rivers are not pure forms; they are a combination of a bedrock channel and an alluvial channel. The way one can distinguish between bedrock rivers and alluvial rivers is through the extent of sediment cover. [1]