Geography chapter 10

• A distributary is an alternative channel that branches out from a river at the river mouth.

  
• A delta is formed where layers of sediment are deposited at the river

  mouth over time.

  
• Condensation is the process through which water vapour in the saturated air changes into very small water droplets.

  
• A drainage basin refers to the area that is drained by a river and its

  tributaries.

  
• Evaporation is the process through which water from the oceans, lakes, rivers and ground is changed into water vapour.

  
• A floodplain is low-lying land that becomes flooded when a river overflows its banks.

  
• The hydrologic cycle is the continuous movement of water from the Earth's surface into the air, and from the air back onto the Earth's surface.

  
• A meander refers to a curve or bend in a river.

  
• Rainfall refers to the amount of rain that an area receives over a period of time.
• The river mouth is the place where the river ends its flow, usually at a sea or lake.

  
• The river source refers to the place at which a river begins.

  
• Runoff refers to the water that does not seep into the ground but flows on the surface from highlands to lowlands.

  
• Transpiration is the process through which plants give out water vapour into the air through their leaves.

  
• A tributary is a stream or river that joins a main river.

  
• A valley is a low area between hills or mountains.
• A waterfall is a vertical flow of fast-moving water falling from a

  great height.

  
• A watershed is an imaginary boundary of a drainage basin, marked by the tops of the surrounding highland.

  
• Almost three quarters of Earth’s surface is covered with water.
• 97 percent of the water on the Earth’s surface is salt water contained in the seas and oceans.
• The remaining three percent of the Earth’s water is fresh water.
• Even then 70 percent of this fresh water is frozen in the form of glaciers and ice sheets.
• 1 percent of the earth’s fresh water is contained in the streams, rivers and lakes.
• People use fresh water for drinking, farming, industry and other activities.
• Water exists in three states: solid, liquid and gas.
• A river is a body of water flowing in a channel.
• The course of river usually begins at the highlands and ends in a lake or sea at the lowlands.
• Steep-sided valley

  
• Fan shaped delta

  
• Bird foot delta

  
• Positive impact of rivers are water supply for farming, fertile soil for farming, water supply for industry, recreation and tourism, source of drinking water and food, production of hydroelectric power and means of transport.
• Negative impact of rivers are loss of lives and property.