EQ1: What are the processes operating within the hydrological cycle from global to local scale? Flashcards
What is essential to life on Earth?
Water
What kind of resource is water?
A scarce resource.
What does failure to carefully manage water promise?
Water insecurity.
The global hydrological cycle isโฆ
of enormous importance to life on Earth.
The drainage basin is an openโฆ
subsystem within the global hydrological cycle.
Water budgets and river systems are strongly influenced by theโฆ
hydrological cycle.
The complex hydrological system adjusts and changes as a result of what?
Physical and human factors.
What is a system?
Any set of interrelated components that are connected together to form a working whole, characterised by inputs, stores, processes (or flows) and outputs.
What are the two types of system?
โข a closed system
โข an open system
When does a closed system occur?
When there is transfer of energy but not matter between the system and its surroundings (the inputs come from within the system).
What does an open system receive?
Inputs from and transfers outputs of energy and matter to other systems.
Why is a hydrological cycle a closed system?
Because all the water is continually circulated through the stores and there is a constant amount of water in the system. The system does not change because there are no gains from or losses to other systems.
What is the global circulation of water driven by?
Solar energy and gravitational potential energy.
How does solar energy drive the cycle?
Global circulation of water is heated by the sun, water on the Earthโs surface evaporates into the atmosphere, while water is also drawn from the soil by plants and evaporated from leaves and stems by the process of evapotranspiration.
What happens when humid air rises?
Condensation occurs at the cooler temperatures, forming clouds, and this eventually leads to precipitation and water is returned back to the land and oceans on the Earthโs surface.
On land, what is gravitational potential energy converted to?
Kinetic energy as the water moves through the system by plant interception, or over land as surface runoff. Water also flows through the soil by processes of infiltration and throughflow.
What happens when water flows through soil by the processes of infiltration or throughflow?
Here it may be stored as soil moisture, or if the bedrock is permeable or porous, will percolate into the rock where itโs stored as groundwater. Some of this water will return to the oceans via streams and rivers
As the global hydrological system is a closed system of interlinked processes, what does this mean for the amount of global water?
It is finite and constant.
What does gravitational potential energy do in the hydrological cycle?
Causes rivers to flow downhill and precipitation to fall to the ground. Keeps water moving through the system in a sequence of inputs, outputs, stores and flows.
Define ๐ฒ๐๐ฎ๐ฝ๐ผ๐ฟ๐ฎ๐๐ถ๐ผ๐ป
Water heated by the sun turns to gas and rises. The conversion of water to vapour.
Define ๐๐๐ฟ๐ณ๐ฎ๐ฐ๐ฒ ๐ฟ๐๐ป๐ผ๐ณ๐ณ
Water that runs across the land into rivers/lakes/oceans.
Define ๐๐ฟ๐ฎ๐ป๐๐ฝ๐ถ๐ฟ๐ฎ๐๐ถ๐ผ๐ป
Water taken up by plants and transpired onto the leaf surface.
Define ๐ด๐ฟ๐ผ๐๐ป๐ฑ๐๐ฎ๐๐ฒ๐ฟ ๐ณ๐น๐ผ๐
Water contained within the soil and underlying rocks, and derived mainly from the percolation of rainwater and meltwater.
Define ๐ฝ๐ฟ๐ฒ๐ฐ๐ถ๐ฝ๐ถ๐๐ฎ๐๐ถ๐ผ๐ป
Rain, sleet, snow etc. Moisture in any form.
Water that fall from clouds
Define ๐ถ๐ป๐๐ฒ๐ฟ๐ฐ๐ฒ๐ฝ๐๐ถ๐ผ๐ป
Temporary storage, as water is captured by plants, buildings, and hard surfaces before reaching the soil.
e.g trees and plants catch the precipitation and slows surface runoff.
Define ๐ถ๐ป๐ณ๐ถ๐น๐๐ฟ๐ฎ๐๐ถ๐ผ๐ป
Water entering the topsoil. Water moves from the surface into the soil and rock below.
Define ๐ฐ๐ผ๐ป๐ฑ๐ฒ๐ป๐๐ฎ๐๐ถ๐ผ๐ป
Water vapour turns back into a liquid and forms clouds
Does the total amount of water in the world change?
NO. Doesnโt change.
What happens when more evaporation occurs as the climate warms?
- Increases moisture levels in the air
- Therefore greater condensation and precipitation.
What are stores?
โReservoirsโ where water is held - all the elements of the hydrological cycle where water remains for a period of time. There are four main stores.
What are the four main water stores?
- Oceans
- Glaciers and ice sheets (cryosphere)
- Surface runoff (in this context, an umbrella term for a number of land based stores such as rivers, lakes, groundwater and the moisture held in soils and vegetation)
- The atmosphere
Define ๐ฎ๐ป๐ป๐๐ฎ๐น ๐ณ๐น๐๐ ๐ฒ๐
The movement of water between the stores over the course of a year.
Define ๐ณ๐น๐ผ๐๐
The transfers of water from one store to another. There are four main flows.
What are the four main flows?
- Precipitation (an input)
- Evaporation
- Transpiration
- Vapour transport
What are fluxes?
The rates of flow between stores.
Where do the greatest fluxes occur?
Over the oceans.
What is the largest water store?
The ocean.
What is the second largest water store?
The cryosphere.
Out of freshwater stores, what is the largest?
The cryosphere (glaciers), accounting for 69% of global freshwater.
What is the second largest freshwater store?
Groundwater, 30% of global freshwater.
Less than 1% of freshwater is stored where?
In the biosphere (vegetation and soil moisture).
In the system of inputs, outputs, stores and flows, what is the ๐ถ๐ป๐ฝ๐๐ into this system?
Precipitation
In the system of inputs, outputs, stores and flows, what are the ๐ผ๐๐๐ฝ๐๐๐ in this system?
Evapotranspiration, runoff
In the system of inputs, outputs, stores and flows, what are the ๐๐๐ผ๐ฟ๐ฒ๐ in this system?
โข interception storage
โข surface storage
โข soil moisture storage
โข groundwater storage
โข channel storage
In the system of inputs, outputs, stores and flows, what are the ๐ณ๐น๐ผ๐๐ in this system?
โข throughfall
โข stemflow
โข surface runoff
โข infiltration
โข throughflow
โข percolation
โข groundwater flow
โข interception
Where is most water on the planet stored?
In the oceans. Oceans hold about 97.5% of water.
About ____ of the Earthโs surface is water-covered.
71%
Whatโs the problem with glaciers being the largest freshwater store?
Theyโre predicted to melt, so could be a problem.
Is there more water stored in the soil or in the atmosphere/rivers?
More water stored in the soil!
What are flows also referred to as?
Transfers.
Define ๐๐ฒ๐ด๐ฒ๐๐ฎ๐๐ถ๐ผ๐ป ๐๐๐ผ๐ฟ๐ฎ๐ด๐ฒ
Ant moisture taken up by vegetation and held within plants.
Define ๐๐๐ฟ๐ณ๐ฎ๐ฐ๐ฒ ๐๐๐ผ๐ฟ๐ฎ๐ด๐ฒ
Any surface water in lakes, ponds, puddles.
Define ๐ด๐ฟ๐ผ๐๐ป๐ฑ๐๐ฎ๐๐ฒ๐ฟ ๐๐๐ผ๐ฟ๐ฎ๐ด๐ฒ
Water held within permeable rocks (also known as an aquifer)
Define ๐ฐ๐ต๐ฎ๐ป๐ป๐ฒ๐น ๐๐๐ผ๐ฟ๐ฎ๐ด๐ฒ
Water held in rivers and streams.
Define ๐๐ต๐ฟ๐ผ๐๐ด๐ต๐ณ๐น๐ผ๐
Also known as inter-flow; water seeping laterally through soil below the surface, but above the water table.
Define ๐ฝ๐ฒ๐ฟ๐ฐ๐ผ๐น๐ฎ๐๐ถ๐ผ๐ป
The downward seepage of water through rock under gravity, especially on permeable rocks e.g sandstone and chalk.
Define ๐๐๐ฒ๐บ ๐ณ๐น๐ผ๐
Water flowing down plant stems or drainpipes.
Define ๐ฏ๐ฎ๐๐ฒ ๐ณ๐น๐ผ๐ (groundwater flow)
Slow-moving water that seeps into a river channel.
Define ๐ฐ๐ต๐ฎ๐ป๐ป๐ฒ๐น ๐ณ๐น๐ผ๐
The volume of water contained within a river channel (also called discharge and runoff)
Define ๐๐๐ฟ๐ณ๐ฎ๐ฐ๐ฒ ๐ฟ๐๐ป๐ผ๐ณ๐ณ
Flow over the surface during an intense storm, or when the ground in frozen, saturated or on impermeable clay.
Define ๐ฟ๐ถ๐๐ฒ๐ฟ ๐ฑ๐ถ๐๐ฐ๐ต๐ฎ๐ฟ๐ด๐ฒ
The volume of water passing a certain point in the channel over a certain amount of time.
What is ๐ฏ๐น๐๐ฒ ๐๐ฎ๐๐ฒ๐ฟ?
The amount of rainfall that enters lakes, rivers and groundwater.
What is ๐ด๐ฟ๐ฒ๐ฒ๐ป ๐๐ฎ๐๐ฒ๐ฟ?
The amount of rainfall that is either intercepted by the vegetation, or enters the soil and is picked up by plants and evapotranspired back into the atmosphere.
What is the largest flux?
Ocean evaporation, 413 thousand kmยณ
What is residence time?
The average length of time that water remains in each store within the hydrological cycle.
What is fossil water?
Untapped ancient stores of freshwater. These are often non-renewable stores.
What is the cryosphere store?
Water stored in glaciers and ice sheets.
What are two stores with the longest residence time?
โข groundwater (up to 10,000 years)
โข oceans and seas (4000 years)
Whatโs a non-renewable water store?
One that is not naturally recharging and is finite (limited in size) and can be used up
What is the store with the shortest residence time?
Biospheric water (1 week)
Pros and cons of groundwater?
Reasonably accessible but difficult to obtain.
What is the ๐ด๐น๐ผ๐ฏ๐ฎ๐น ๐๐ฎ๐๐ฒ๐ฟ ๐ฏ๐๐ฑ๐ด๐ฒ๐?
The balance of water between the stores in the hydrological cycle.
How could water be considered a renewable resource?
The constant circulation, albeit at variable speeds, means that water is generally considered a renewable resource, replenished naturally.
What type of water is an exception to being renewable?
Fossil water, water that has been contained in an undisturbed space, usually groundwater in an aquifer, for millennia or longer. In arid regions e.g Sahara, the fossil water in these aquifers may be extracted for human purposes (agriculture, industry), but there is little to no significant recharge, effectively making this type of groundwater a non-renewable resource.
What percentage of freshwater is locked up in glaciers and ice sheets?
70%. Only 1% of all freshwater is โeasily accessible surface freshwaterโ.
Do oceans lose more water through evaporation or gain more water from precipitation?
Lose more water through evaporation.
Do landmasses lose more water through evaporation or gain more water from precipitation?
Gain more from precipitation.
What makes up the difference between the processes from oceans and landmasses?
Surface runoff - known as the balance.
What happens if this balance (oceans losing more water through evaporation rather than gaining more from precipitation) is disturbed?
The oceans would receive more water and the continents would be dry. The global water budget ensures this doesnโt happen.
Does water reside in oceans for shorter or longer periods?
Longer periods.
What is a ๐ฑ๐ฟ๐ฎ๐ถ๐ป๐ฎ๐ด๐ฒ ๐ฏ๐ฎ๐๐ถ๐ป?
An area of land that is drained by a river and its tributaries, and separated from neighbouring drainage basins by a ridge of high land called a watershed or divide.
It includes water found in the water table and surface runoff.
Is a drainage basin an open or closed system?
An open system. Itโs a subsystem within the global hydrological cycle linked to other systems by inputs and outputs and involves a number of linked processes and stores.
Define ๐๐ฎ๐๐ฒ๐ฟ๐๐ต๐ฒ๐ฑ
The boundary of a drainage basin, a high ridge of land marking the edge of a drainage basin.
Can drainage basins vary in size?
Yes, from that of a small local stream up to a huge river like the Amazon.
What is the ๐๐ฎ๐๐ฒ๐ฟ ๐๐ฎ๐ฏ๐น๐ฒ?
The boundary between the unsaturated zone and the saturated zone underground
Whatโs a ๐ฐ๐ผ๐ป๐ณ๐น๐๐ฒ๐ป๐ฐ๐ฒ?
Occurs when two or more flowing bodies of water join together to form a single channel.
