Still River

Still River

This is taken Great Ocean Road's secret place. There is these river like water on the beach and it's still (well, at least to me). The colour of the deep blue sky is vividly reflected on the non moving mirror-like water. The opposite of this place has some Koalas living in its natural environment.

Topography

A river is a large natural waterway. The source of a river may be a lake, a spring, or a collection of small streams, known as headwaters. From their source, all rivers flow downhill, typically terminating in the ocean. The mouth, or lower end, of a river is known as its base level.

Over time, rivers cut away at their beds, eventually forming a more gentle gradient.

• Youthful river - a river with a steep gradient that has very few tributaries and flows quickly. Its channels erode deeper rather than wider.
• Mature river - a river with a gradient that is less steep than those of youthful rivers and flows more slowly than youthful rivers. A mature river is fed by many tributaries and has more discharge than a youthful river. Its channels erode wider rather than deeper.
• Old river - a river with a low gradient and low erosive energy. Old rivers are characterized by flood plains.
• Rejuvenated river - a river with a gradient that is raised by the earth's movement.

Rating systems

• International Scale of River Difficulty - The scale is used to rate rivers -- particularly those with rapids -- for navigation. Class I is the easiest and Class VI is the hardest.
• Strahler Stream Order - The Strahler Stream Order is a method to rank rivers based on the connectivity and hierarchy of contributing tributaries. Headwaters are first order while the Amazon River is twelfth order. Approximately 80 percent of the rivers and streams on Earth are of the first and second order.
  
  

The world's ten longest rivers

It is difficult to measure the length of a river, mainly because rivers have a fractal property, which means that the more precise the measure, the longer the river will seem. Also, it is difficult to determine exactly where a river begins or ends, as very often, upstream rivers are formed by seasonal streams, swamps, or changing lakes.

These are average measurements.

1. Nile (6,690 km)
2. Amazon (6,452 km)
3. Mississippi-Missouri (6,270 km)[2]
4. Yangtze (Chang Jiang) (6,245 km)[3]
5. Yenisey-Angara (5,550 km)
6. Huang He (Yellow) (5,464 km)
7. Ob-Irtysh (5,410 km)
8. Amur (4,410 km)
9. Congo (4,380 km or 4,670 km). (The source of this river is disputed.)
10. Lena (4,260 km)

(courtesy wikipedia.com)