THE WATER CYCLE - LOCAL SCALE

Inputs

• precipitation

Outputs

• Evapotranspiration ( water returning to atmosphere by evaporation and transpiration )

• Streamflow ( water that flows through streams into the sea or rivers )

Stores

• groundwater ( water stored in pores of rock )

• Soil water

• Rivers

• Interception ( water stored temporarily by trees before it reaches the ground )

• Surface

Flows

• infiltration ( above ground into soil )

• Percolation ( ground or soil into porous rocks )

• Throughflow ( through the soil )

• Surface run off

• Groundwater flow

• Stream flow

• Stem flow ( flow of water that has been intercepted )

Water balance

• expresses process of water storage and transfer in a drainage system

• Uses the formula: precipitation = total run off + evapotranspiration ± storage

Water cycle impacted on local scale by

• deforestation ( less interception,less storage )

• Storm events ( increased run off, increased water storage )

• Seasonal changes

• Agriculture ( ground is compacted= less infiltration)

• Urbanisation ( impermeable surfaces = more run off )