The friction factor is affected by variations of fluid physical properties caused by variations in temperature and by the action of buoyancy forces. In rough channels the hydraulic resistance increases due to formation of vortices at the roughness elements leading to additional loss of flow specific energy. Three types of roughness can be distinguished: Natural roughness, which is formed as a result of long operation of pipelines.
Erosion by Glaciers. Like flowing water, flowing ice erodes the land and deposits the material elsewhere. Glaciers cause erosion in two main ways: plucking and abrasion. Both are illustrated at this link: [Insert a link to an animation showing how glaciers cause erosion by plucking and erosion.] Plucking is the process by which rocks and other sediments are picked up by a glacier.
Types of Water Erosion. The four types of water erosion are as follows: 1  Inter-rill erosion: the movement of soil by rain splash and its transport by this surface flow. 2  Rill erosion: erosion by concentrated flow in small rivulets.3  Gully erosion: erosion by runoff scouring large channels (deeper than 1 foot). Inter-rill erosion: the movement of soil by rain splash and its transport by this surface flow. 2  Rill erosion: erosion by concentrated flow in small rivulets. 3  Gully erosion: erosion by runoff scouring large channels (deeper than 1 foot). 4  Streambank erosion: erosion by rivers or streams cutting into banks.