Chapter 1: The operations and importance of the hydrological cycle Flashcards
Name the 6 water stores in order of volume from largest to smallest
The Ocean, Cryosphere, Ground water, Surface water, Soil moisture and Atmospheric moisture
Name the water stores in order of most to least content of fresh water
Cryosphere, ground water, surface water, soil moisture, atmospheric moisture and the ocean
Name the water stores in order of shortest to longest residence time
Atmospheric moisture, soil moisture, surface water, ground water, the ocean and the cryosphere
How is fresh water distributed across the stores?
69% is stored in the cryosphere
30%is stored in ground water
1% is stored in surface water
How is accessible fresh water distributed?
52% is stored in lakes
38% is stored in soil moisture
Define base flow
Base flow is the flow of water into the river channels
Define through flow
Water seeps laterally past the soils surface but above the table
Define river discharge
The volume of water passing a certain point over time
How much of global water is harvested for human use?
0.07% of global water is both accessible and fresh enough for human us. This is found in rivers and lakes.
Describe the conditions for precipitation
Air cooled for saturation point with a relative humidity of 100%
Condensation of nuclei, eg. dust particles condenses vapor upon contact making droplets
A temperature below dew point
What factors affect the drainage basin?
Amount of precipitation Intensity of precipitation Type of precipitation Variability of precipitation Seasonality of precipitation Distribution of precipitation
What are the 3 types of precipitation variability?
Secular- long term change eg. climate change
Periodic- annual/monthly change
Stochastic- random variability eg. a rainstorm
Name and summarise the 3 types of rainfall
Convectional rain: Hot land heats air which rises and cools. It then condenses creating rain
Cyclonic rain: Warm air rises over cool air so that it condenses and forms rain
Orographic rain: air is forced over a barrier so that it condenses and forms precipitation
Name 6 factors that influence infiltrationrates
Length of periods of rainfall Antecedent rain Porosity of the ground Vegetation The size of the raindrops The steepness of the ground
Define albedo
A measure of the proportion of incoming solar radiation that is reflected back into the atmosphere.
Define PEVT
Potential evapotranspiration which shows the output of water if there was unlimited soil water
Water budgets are used by who?
Farmers, local and international governments
What is a river regime?
A river regime is the annual variation in discharge or flow of a river at a particular point.
Name 6 factors which can influence a rive regime
The size of a river The amount,pattern, density of precipitation Temperature Geology and soil Amount/type of vegetation Human activities e.g dam building
Name 5 physical factors affecting drainage basins
Climate Soils Relief Vegetation Geology
Name 5 human factors affecting drainage basins
Water management Climate Change Urbanisation Deforestation Afforestation
What is a storm hydrograph?
Storm hydrograph’s are data sets which show the variation of discharge over short periods of time. They record change in discharge in response to inputs.
Describe the conditions of a “flashy” river or hydrograph
Impermeable ground less porous ground Steep slope Straight river Saturated Bare/urbanised
Describe the conditions of a “flat” river or hydrograph
Permeable Porous Flatter Several bends Dry ground Lots of vegetation
Compare “flashy” and “flat” hydrograph’s
Flashy hydrograph’s have a steeper rising limb
Flat hydrograph’s have a lower peak
Flat hydrograph’s have a longer lag time
What is a green roof?
A green roof is a vegetation cover that is placed over a water proof membrane
What is am infiltration basin?
A shallow depression dig out to delay runoff and increase infiltration
What’s rainwater harvesting?
collecting rainwater from roofs to be recycled
What does SuDS stand for
Sustainable Drainage system
What are filter drains?
Trenches filled with gravel to take runoff away
What is the NPPF?
The national planning policy framework
