The phrase "river mainstream" is grammatically correct and can be used in written English.
It refers to the main channel or course of a river, as opposed to any tributaries or smaller streams that may branch off from it. Example: The river mainstream was calm and peaceful, with gentle currents and picturesque views of the surrounding landscape. However, as we ventured further upstream, the water became rougher and the current stronger.
Datong Hydrographic Station (DHS; 117°37'E, 30°46'N as shown in Fig. 1), located 625 km inland from the river mouth on the mainstream, is free from tide influence.
Some propose damming the mainstream Mekong, the great river upon which millions of people rely to provide their fish catch and fertilise their rice paddies.
This poster is the visual equivalent of Enoch Powell's "rivers of blood" speech, which ended his mainstream political career in 1968.
Specifically, it consists of creating regional mechanisms for cooperation, engaging mainstream political leaders from rival river-boardering countries, and enabling them to negotiate trade-offs between water and other public goods.
We collected 30 river bed sediment samples along the Yangtze River, including the mainstream and major tributaries.
The trend implies either that we were sampling progressively sandier material downstream (Fig. 9c) or that less altered material is being added to the mainstream from other sources, such as from river terraces.
However, the low-saturation area was not large enough for fish to avoid the negative effects of TDG saturation due to a sharp river slope and a large flow ratio between the mainstream and its tributary.
Table 2 D/z ratio in world rivers D/z (cm/h) Reference Rhône 15 53 Saône 8 15 53 Amazon mainstream 10 13 Amazon tributaries 5 13 St Lawrence 15 58 Ottawa 4 15 Hudson 4.1 6 Changjiang 8 .
If we consider only K2O/Al2O3, then we can see that the chemical weathering state at the river mouth is similar to that through much of the mainstream, although the sediments in the uppermost Jinshajiang do seem to be slightly more altered than most of the mainstream, despite the fact that they are close to their source regions.
The word "mainstream" denotes the vast center of the human river, the "main" part of the "stream" if you will.
