The Water Balance Flashcards
What’s the equation for the water balance?
Precipitation = total runoff + evapotranspiration +/- change in storage
What type of changes are the water balance dependent on?
Seasonal variations
Temperature
Precipitation
Runoff
Evapotranspiration
What are the two factors the water cycle are effected by on a local scale?
Deforestation
Storm events
How does deforestation effect the water cycle on a local scale?
Less interception by trees
Increased surface runoff
Soil No longer held together by the roots of trees
Soil water storage decreases
Fewer plants so transpiration decreases
Soil susceptible to erosion
How do storm events effect the water cycle on a local scale?
Large amounts of rainfall
Oversaturated ground
No more water can infiltrate soil
Increases surface runoff
What are the three changes that have a big impact on both global and local scales on the water cycle?
Seasonal changes
Agriculture
Urbanisation
How does seasonal changes in summer and winter vary and how does this effect the water cycle?
Summer is less rain so ground is dryer and harder so more impermeable encouraging surface runoff.
Winter the ground may be frozen so impermeable so encouraging runoff. Snow discourages runoff as it takes time to melt.
How does agriculture effect the water cycle?
Pastoral farming with livestock trample the ground reducing infiltration.
Arable farming increases infiltration with ploughing creating looser soil decreasing surface runoff. Howver digging drainage ditches increases surface runoff and streamflow.
Irrigation can lead to ground water depletion.
What’s the difference between pastoral and arable farming?
Livestock vs crops
What is irrigation?
Movement of water by human intervention
How does urbanisation effect the water cycle?
Roads and buildings are impermeable surfaces which reduce infiltration and increase surface runoff reducing lag time increasing flood risk
