Drainage Basin Flashcards
Processes that drive change in the drainage basin
Evaporation
Percolation
Groundwater flow
Through flow
Surface runoff
Infiltration
Transpiration
Interception
Precipitation
Through fall
Stem flow
Channel flow
How does vegetation density affect the drainage basin system?
Increased interception
Increased evapotranspiration
Decreased infiltration
Decreased runoff
How does relief of land affect processes in the drainage basin system?
Steeper gradients increase surface runoff
Less infiltration
How does precipitation intensity affect the processes in the drainage basin?
More intense precipitation reduces infiltration as the soil becomes more saturated
Increased runoff
What is the water balance?
Amount of water in ground water storage
Outlines the balance between inputs and outputs
What is the equation for water balance?
Precipition= runoff + evapotranspiration +/- change in storage
Water balance during winter
Precipitation exceeds evaporation and soil moisture is recharged
Soil moisture surplus
Water balance first half of summer
Evaporation exceeds precipitation
Soil moisture is utilised
Water balance in second half of summer
Soil moisture deficit
Water balance in autumn
Precipitation higher than evaporation
Soil moisture recharged
What factors cause flashy flood risk
More rounded drainage basin
Steep slopes
Shallow soil
Impermeable rocks
Intense precipitation
Low vegetation density
Urbanisation
Saturated/baked/frozen ground
Which factors cause subdued flood risk
Elongated drainage Bain
Gentle slopes
Deeper soil
Permeable rocks
Gentle storm
Forests
Less urbanised areas
Natural factors that affect the water cycle
Storm events
Seasonal change
Human factors affecting the water cycle
Land use change- deforestion
Farming practices
Urbanisation
Water abstraction
