A river is a natural flowing watercourse, usually freshwater, flowing towards an ocean, sea, lake or another river. In some cases, a river flows into the ground and becomes dry at the end of its course without reaching another body of water.

1An artificial underground passage, especially one built through a hill or under a building, road, or river. ‘Local villagers cut a tunnel road through the mountain and named it Guoliang Cave. ‘

mouth of the river

headwaters

3 Stages of a River

• YOUTHFUL STAGE (UPPER COURSE) – V- Shaped Valley > Erosion.
• MATURE STAGE (MIDDLE COURSE) – Meanders > Erosion and Deposition.
• OLD AGE STAGE (LOWER COURSE) – Floodplains > Deposition.
• Advantages. Scenic Attraction.
• Dangers. Flooding – Damage to property, land, animals and homes.
• Advantages.
• Disadvantages.

These categories are: Youthful, Mature and Old Age. A Rejuvenated River, one with a gradient that is raised by the earth’s movement, can be an old age river that returns to a Youthful State, and which repeats the cycle of stages once again. A brief overview of each stage of river development begins after the images.

The headwater can come from rainfall or snowmelt in mountains, but it can also bubble up from groundwater or form at the edge of a lake or large pond. The other end of a river is called its mouth, where water empties into a larger body of water, such as a lake or ocean.

In limnology (the study of inland waters), a stream bank or river bank is the terrain alongside the bed of a river, creek, or stream. Stream banks are of particular interest in fluvial geography, which studies the processes associated with rivers and streams and the deposits and landforms created by them.

Rivers are split up into three parts: the upper course, the middle course, and the lower course. The upper course is closest to the source of a river. The land is usually high and mountainous, and the river has a steep gradient with fast-flowing water. There is a lot of vertical erosion and weathering.

An estuary is an area where a freshwater river or stream meets the ocean. When freshwater and seawater combine, the water becomes brackish, or slightly salty.

Upper course river features include steep-sided V-shaped valleys, interlocking spurs, rapids, waterfalls and gorges. Middle course river features include wider, shallower valleys, meanders, and oxbow lakes. Lower course river features include wide flat-bottomed valleys, floodplains and deltas.

The water mass in rivers is in motion, unidirectional and sometimes of great force. Their outstanding function is the transport of water; with changes of discharge and velocity of water movement they erode the land and carry sediment and often bedload for, sometimes, long distances.

Rivers are split up into three parts: the upper course, the middle course, and the lower course. The upper course is closest to the source of a river. The land is usually high and mountainous, and the river has a steep gradient with fast-flowing water.

For instance, the Amazon River receives water from more than 1,000 tributaries. Together, a river and its tributaries make up a river system. A river system is also called a drainage basin or watershed. A river’s watershed includes the river, all its tributaries, and any groundwater resources in the area.