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.
Erosion is the wearing away of the surface of the earth! Erosion is the process by which soil and rock are removed from the Earth's surface by natural processes such as wind or water flow, and then transported and deposited in other locations.The wearing away of land or soil by the action of wind, water, or ice.In hydrologic terms, wearing away of the lands by running water, glaciers,winds, and waves, can be subdivided into three process: Corrasion, Corrosion, and Transportation.he wearing away of land or soil by the action of wind, water, or ice. In hydrologic terms, wearing away of the lands by running water, glaciers,winds, and waves, can be subdivided into three process: Corrasion, Corrosion, and Transportation.