Geography: rivers

• Development along rivers has led to increased pollution levels due to industrialisation and urbanisation.
• Rivers are important to people as they can be used for transport, irrigation, hydroelectric power generation, tourism, recreation, fishing, drinking water supply, flood control, waste disposal.
• Rivers are important sources of water, providing drinking water for human consumption and irrigation for agriculture.
• meanders: water flows faster on the outer bend bend of the river where the channel is deeper and has less resistance from rocks. water is directed around the bend as it flows through the meanders. This causes greater erosion which widens the channel and creates a bigger curve. this results in the formation of a steep river cliff
• In contrast the water on the inner bend of the river is shallow and slow flowing so there is little erosion as it does not have as much energy. because of its lack of energy it cannot transport large rocks so deposition occurs. over time material builds up to create a slip off slope
• The process of meander cut-off happens when the river changes course and cuts across the neck of an oxbow lake
• eventually the outside bend on the meander will erode through to the other side creating a straight channel. This leaves scars on the remaining land where the meanders once were
• these scars are called ox bow lakes or meander loops
• oxbow lakes form when the river changes course due to erosion at the end of one of its bends. The new path that the river takes forms a loop with the old channel becoming isolated from the main flow of the river. Over time vegetation grows within the former river bed forming a small lake known as an oxbow lake
• Ox bow lakes also act as floodplains during times of flooding they store excess water that would otherwise cause damage downstream
• Floodplains are important habitats for many species of plants and animals. They often contain wetlands such as marshes and swamps which support a wide variety of wildlife including birds, insects and mammals. Many rare plant species grow here too
• Levee: A raised bank of earth or stone, built along the edge of a river to prevent flooding. The land behind it are usually flood plains which are used for farmland as building on the land would be hard as the ground is soft and also in case of flood damage
• The levees protect the towns and cities from being destroyed by floodwaters. In some cases, the levees have been breached causing widespread destruction.