Please enable JavaScript.
Coggle requires JavaScript to display documents.
The Hydrological Cycle (Factors affecting river regime (Drainage basin…
The Hydrological Cycle
Stores = this is where water is held
The main stores are the Oceans, ice caps, groundwater, rivers and lakes
Some stores are non-renewable such as fossil water and cryosphere
Water stores all have different residence times
Flows = the process of transferring water from one area to another
Precipitation / evapotranspiration / percolation / runoff
Only 1% of global fresh water is accessible
Hydrological cycle as a closed system
Water is continually circulated
Constant amount of water
No gains or losses from other systems
Physical Factors affecting drainage basin
Climate = amount of evaporation
Soils = determine amount of infiltration
Geology = amount of runoff
Relief = surface runoff
Vegetation = interception rates
Human factors affecting drainage basin
Evaporation - increased
Runoff - increased
Interception - reduced
Infiltration - reduced
Groundwater - reduced
Hurricane Harvey - Case Study
In a 4 day period more than 40 inches of rain
Displaced 30,000 people
Economic losses at $75 billion
Houston vulnerable because of flat geography
800 miles of creeks makes it easy to flood
Water budget = shows the annual balance between inputs and outputs P = R+E+S
Soil moisture surplus = precipitation > potential ept
Soil moisture utilisation = pet > precipitation
Soil moisture recharge = pet decreases so soil stores fill up
Field capacity = the point where the soil is full of water
Factors affecting river regime
Drainage basin area
Maximum altitude
Geology
Annual precipitation
Land use
Mean discharge
Storm Hydrograph
Shows variation in a river's discharge at a specific point
Rising limb = increase in discharge in response to surface runoff
Peak discharge = maximum discharge in response to rainfall
Falling limb = decline in discharge that occurs after peak flow
Lag time = difference in hours between maximum ppt and time of peak discharge