2.2.1 Hydrological Characteristics

The Characteristics & Processes of Rivers

The Characteristics & Processes of Rivers

Water on Earth

• Only 2.5% of the water on Earth is freshwater

• 68.7% of freshwater is stored in glaciers and ice sheets and 30% is groundwater

• The remaining 1.3% of freshwater is in rivers, soil moisture, lakes and the atmosphere

• All water is part of the hydrological cycle

Sources of Water

Hydrological cycle 

• The hydrological cycle is a closed system 

• Water is constantly recycled through the system

• Within the hydrological cycle, there are stores and transfers (flows)

The Hydrological Cycle

• Stores are those places where water is held for a period of time. These include:

  • Water in the atmosphere in the form of water vapour or water droplets in clouds

  • Surface stores such as puddles, lakes, rivers and reservoirs

  • Interception is how precipitation is prevented from reaching the ground, usually by being caught on leaves or branches

  • Aquifers are permeable rocks such as limestone and sandstone which can hold water 

  • Ice and snow

  • Seas and oceans 

• Flows  are the ways in which water is moved around the hydrological cycle. They include:

  • Evaporation

  • Condensation

  • Transpiration 

  • Evapotranspiration

  • Precipitation

  • Overland flow

  • Infiltration

  • Percolation

  • Through flow 

  • Groundwater flow