1.1 – Systems in Physical Geography
Inputs:
- Precipitation
- Leaf fall during autumn
- Seeds carried by wind and birds
Stores/ components:
- Water
- Soil
- Plants
Outputs:
- Water soaking through soil and rocks
- Evaporation
- Seed dispersal
Flows/ transfer:
- Photosynthesis
- Infiltration
- Transpiration
Input Material or energy entering a system from the outside
Output Material or energy moving from a system to the outside
Energy Power or driving force
Stores/Components A part of the system where energy/ mass is stored or transformed
Flows/transfers A form of linkage between one store/ component and another that
involves movement of energy or mass. (precipitation...)
Dynamic when the inputs and outputs are balanced in a system over a long period
equilibrium of time.
Positive Feedback When the effect of an action is amplified or leads to further effects.
Negative Feedback When the effect of an action is cancelled out by knock-on effects.
Open system Matter and energy can be transferred from the system across the
boundary into the surrounding environment.
Closed System These have transfers of energy into and out of the system boundary but
not a transfer of matter
, 1.2 - The Global Water Cycle
These components fall into two kinds of process:
• Stores: oceans, lakes, rivers, the atmosphere...
• Transfers: the processes involved in transferring water between stores.
The main stores in the water cycle à subsystems:
• Atmosphere – air
• Lithosphere – land
• Hydrosphere – water (97.5% in ocean)
• Biosphere – living things
• Cryosphere –snow and ice (almost 2.5%)
The global distribution of water stores: on land there is an uneven distribution of rivers,
lakes and groundwater
Global distribution of groundwater aquifers: 30% of freshwater is stored in rocks in
underground reservoirs called aquifers.
Inputs:
- Precipitation
- Leaf fall during autumn
- Seeds carried by wind and birds
Stores/ components:
- Water
- Soil
- Plants
Outputs:
- Water soaking through soil and rocks
- Evaporation
- Seed dispersal
Flows/ transfer:
- Photosynthesis
- Infiltration
- Transpiration
Input Material or energy entering a system from the outside
Output Material or energy moving from a system to the outside
Energy Power or driving force
Stores/Components A part of the system where energy/ mass is stored or transformed
Flows/transfers A form of linkage between one store/ component and another that
involves movement of energy or mass. (precipitation...)
Dynamic when the inputs and outputs are balanced in a system over a long period
equilibrium of time.
Positive Feedback When the effect of an action is amplified or leads to further effects.
Negative Feedback When the effect of an action is cancelled out by knock-on effects.
Open system Matter and energy can be transferred from the system across the
boundary into the surrounding environment.
Closed System These have transfers of energy into and out of the system boundary but
not a transfer of matter
, 1.2 - The Global Water Cycle
These components fall into two kinds of process:
• Stores: oceans, lakes, rivers, the atmosphere...
• Transfers: the processes involved in transferring water between stores.
The main stores in the water cycle à subsystems:
• Atmosphere – air
• Lithosphere – land
• Hydrosphere – water (97.5% in ocean)
• Biosphere – living things
• Cryosphere –snow and ice (almost 2.5%)
The global distribution of water stores: on land there is an uneven distribution of rivers,
lakes and groundwater
Global distribution of groundwater aquifers: 30% of freshwater is stored in rocks in
underground reservoirs called aquifers.
