Rivers:
          Rivers form part of the water cycle - the continuous circulation of water between the land, sea, and atmoshphere. The source of a river may be a mountain spring or lake, or a melting glacier. The course that the river subsequently takes depends on the slope of the terrain and on the rock types and the formations over which it flows. In its early, upland stages, a river tumbles steeply over rocks and boulders and cuts a steep - sided V- shaped valley. Farther downstream, it flows smoothly over the sediments and forms winding meanders, eroding sideways to create broad valleys and plains. on reaching the coast, the river may deposit sediment to form an estuary or delta.

 

 
Features:
             Rivers are one of the major forces that shape the landscape. Near its soirce, a river is steep. it erodes downwards, carving out V- shaped valleys and deep gorges. Waterfalls and rapids are formed where the river flows from hard rock to softer, more easily eroded rock. Farther downstream, meanders may form and there is greater side ways eroison, resulting in the broad river valley. The river sometimes erodes through the neck of a meander to form an oxbow lake. Sediment deposited on the valley floor by meandering rivers and during floods helps to create a flood - plain. Floods may also deposit sediment on the banks of the river to form levees. As a river spills into teh sea or a lake, it deposits large amount of sediment, and may form a delta. A delta is an area of sand - bars, swamps, and lagoons through which the river flows in several channels called distributaries for example. Often, a rise in the sea level may have flooded the river - moth to form a broad estuary, a tidal section where sea water mixes with the fresh water.  

Glaciers:
             A valley glacier is a large mass of ice that forms on land and moves slowly downhill under its own weight. It is formed from snow that collects in cirques and compresses into ice as more and more snow accumulates. The cirque is deepened by frost wedging and abrasion and aretes develop between adjacent cirques. Eventually, so much ice builds up that the glacier begins to move downhill. As the glacier moves its collects moraine, which may range in size from particles of dust to large boulders. The rocks at the base of the glacier erode the glacial valley, giving it a U - shaped cross-section.  Under the glacier, eroded outcrops of hard rock and drumlins are left behind the valley floor. The glacier end s at a terminus where the ice melts as fast as it arrives. If the temperature increases, the ice melts faster than it arrives, and the glacier retreats . the retreating glacier leaves behind its moraine and also erratics. Glacial streams form the melting glacier deposit eskers and kames, but carry away the finer sediment to form a stratified outwash plain. Lumps of ice carried on to this plain melt, creating holes called kettles.