The Hydrological Cycle

?
  • Created by: Helena26
  • Created on: 02-02-13 19:30
What is the The Hydrological Cycle?
This describes the process whereby water in its various forms is continually cycled between the land, sea and atmosphere. It also makes its way into the biosphere to influence animal and plant ecosystems around the globe.
1 of 32
What type of system is The Hydrological Cycle?
A closed system.
2 of 32
What is The drainage basin system?
An open system.
3 of 32
What do they both consist of?
Both consist of transfers, stores, inputs of water
4 of 32
Why is the hydrological cycle a closed system?
The hydrological cycle is a closed system as no gains or losses from outside are added to the system.
5 of 32
Why is the drainage basin system said to be open?
The drainage basin system is said to be open as both inputs and outputs of energy and material occur.
6 of 32
What do all systems in their natural state aim to be?
All systems in their natural state aim to be in a state of balance (dynamic equilibrium) as this is when they function best.
7 of 32
What can easily upset the balance?
Heavy rainfall, drought and human activity such as deforestation can easily upset the balance.
8 of 32
Within the hydrological cycle, what four main processes operate?
Interception, Evapotranspiration, Infiltration and Precipitation.
9 of 32
What is interception?
This is when plants prevent some rainfall from directly reaching the ground, for example, water on leaves or foliage. It may later reach the floor via stem flow or through-fall, where water drips to the ground.
10 of 32
What is evapotranspiration?
Water lost from vegetation via both evaporation and transpiration.
11 of 32
What is the definition of evaporation?
A physical process where moisture is lost directly to the atmosphere from soil and water surfaces due to the suns heat.
12 of 32
What is the definition of transpiration?
A biological process where water is lost from stomata pores in plant leaves.
13 of 32
What is Potential Evapotranspiration?
The amount of water that could be lost by evapotranspiration. For example, this is potentially high in deserts, but the amount that can take place is limited due to the minimal moisture available.
14 of 32
What is actual evapotranspiration?
Actual evapotranspiration is what actually occurs. In the UK there is more water available for evapotranspiration than takes place.
15 of 32
What is infiltration?
Where water slowly soaks into the soil from the ground. The maximum rate at which this can occur is known as infiltration capacity (mm/hour) and it is dependent on the amount of water already present in soil structure and vegetation.
16 of 32
What is precipitation?
The most important input into the system forms includes snow, hail, rain, and fog.
17 of 32
What is Percolation?
Water in the soil does not remain there but moves down slowly into the lower layers of soil and rock. It creates groundwater storage found in rocks and this may later be moved sideways through the rock via groundwater flow.
18 of 32
What three ways can water flow through the hydrological cycle?
Throughflow, Channel flow, Groundwater flow.
19 of 32
What is throughflow?
Where water moves downwards through layers of soil.
20 of 32
What is Channel flow?
Downhill movement of water in rivers.
21 of 32
What is groundwater flow?
Lateral movement of water from the water table.
22 of 32
What is a drainage basin?
All rivers receive a water supply and the area of land this comes from is known as a drainage basin.
23 of 32
What are the boundaries of a drainage basin called and where are they normally marked?
Watershed and will usually be marked by areas of higher land.
24 of 32
What influences drainage basins on how quick or slow the main river within them responds to intense rainfall.
Drainage basins have many different characteristics.
25 of 32
What is drainage density?
This relates to the number of streams in a particular drainage basin and can be measured by dividing total length of all streams in a basin (L) by its area (A). As a rule, the higher the drainage density (D) the more quickly water drains to a river.
26 of 32
What are the characteristics of high-density drainage basins?
High density (+2km per km2) Impermeable land surface, steep slopes, limited vegetation cover, limited rainfall, gentle slopes, large channel frequency (tributaries).
27 of 32
What are the characteristics of low-density drainage basins?
Low density (-2km per km) Permeable rock, for example, chalk, much vegetation cover, limited rainfall, gentle sloes, lower channel frequency.
28 of 32
What are first-order streams?
Original, single source tributaries.
29 of 32
What are the second-order streams?
The joining of two first order streams.
30 of 32
What are the third-order streams?
The merging of two-second order streams.
31 of 32
What are relationships are also found between?
Stream order and the number of stream in a drainage basin (negative correlation). Stream length and stream order (positive correlation). Area of drainage basin and stream order (positive correlation).
32 of 32

Other cards in this set

Card 2

Front

What type of system is The Hydrological Cycle?

Back

A closed system.

Card 3

Front

What is The drainage basin system?

Back

Preview of the front of card 3

Card 4

Front

What do they both consist of?

Back

Preview of the front of card 4

Card 5

Front

Why is the hydrological cycle a closed system?

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Geography resources:

See all Geography resources »See all Rivers and fluvial processes resources »