Mountain river

This article is about a type of stream. For other meanings, see Mountain River.

The Korkeakoski rapids of Tuovilanlahti in Maaninka, Kuopio, Finland are formed by a fan-shaped area of jagged rocks.

Mountain rivers are a type of river, which flow in narrow, deep valleys with steep banks, rocky stream beds, and typically accumulated rock debris.

They are characterized by high slope and flow velocity, insignificant depth and frequent rapids and waterfalls. ^[1] The stream gradient of a mountain river is normally significantly greater than typical rivers. ^{[2] : 16–17}

They play an essential role in shaping the surrounding landscape through erosion and deposition, creating deep valleys, gorges, and waterfalls. Waterfalls are known to contribute to the erosion profile of mountain rivers as the water descends from the mountain. ^[3]

Pollution by humans has affected mountain rivers and their river ecology, influencing both their bacterial ecosystems ^[4] as well as temperature due to climate change. ^[5] Mountain rivers are some of the most vulnerable to increases in temperature, which causes drying that affects the water supply for many people. ^[6] Since the 2000s, there has been an increase in restoration and rehabilitation of mountain rivers. ^[6]

Morphology

The channel of a mountain river often changes chaotically as it progresses downstream, ^{[2] : 16} changing width and depth significantly both over space and over time as erosion alters the shape of the stream.

Mountain rivers with high flow, either persistently or transiently as the result of annual summer periods of greater flow, typically carrying large sediment greater than 64 millimeters in diameter. ^{[2] : 17} The lack of finer sediment can create exceptionally clear water. ^{[2] : 24} While mountain water may appear clean, it can still contain a diverse ecosystem of bacteria and viruses, which must be filtered and disinfected to become potable. ^[7]

Human uses

Mountain rivers play a significant role in providing water for agricultural and urban use. As of 2011, up to 80% of US drinking water originated from mountain snow. ^[6] Increases in population has spurred settlement into mountainous areas, influencing the local ecology and contributing to deforestation. ^{[2] : 8}

See also

• Upland and lowland (freshwater ecology)
• Category:Rivers by mountain range

References

1. "River Systems and Fluvial Landforms – Geology (U.S. National Park Service)". National Park Service. Retrieved 14 July 2024.
2. Wohl, Ellen E. (2001). Virtual rivers : lessons from the mountain rivers of the Colorado front range . New Haven. ISBN   9780300084849. LCCN   00043771.
3. Rothman, Sophie; Scheingross, Joel; McCoy, Scott; Dow, Helen (2023). "Impacts of spontaneous waterfall development on bedrock river longitudinal profile morphology". Journal of Geophysical Research – Earth Surface. doi:10.1029/2022JF007057.
4. Lenart-Boroń, A.; Boroń, P.; Kulik, K.; et al. (28 October 2022). "Anthropogenic pollution gradient along a mountain river affects bacterial community composition and genera with potential pathogenic species". Scientific Reports. 12 18140. doi: 10.1038/s41598-022-22642-x .
5. Niedrist, G.H. (18 February 2023). "Substantial warming of Central European mountain rivers under climate change". Regional Environmental Change. 23 43. doi: 10.1007/s10113-023-02037-y .
6. Wohl, Ellen E. (6 December 2011). "Mountain Rivers Revisited". Eos (Interview). 92 (49). Interviewed by Schultz, Colin. doi: 10.1029/2011EO490012 .
7. "Two Ways to Purify Water". National Park Service . Retrieved 14 August 2025.