Natural Geographical Systems

what is a system?

what is a system?

an assemblage of interrelated parts that work together by way of some driving process. They are a series of stores or components that have flows or connections between them

why are systems important in geography?

many aspects of geography are very complex so we try to simplify them by using models (like systems) - they are a simplification of reality

inputs

adding energy/matter to a system

stores

a part where energy/matter is stored (or transformed)

flows

energy/matter moving from one store to another

outputs

removing energy/matter from a system

3 types of systems

isolated - no inputs or outputs (very rare)

closed - only inputs/outputs is energy

open - inputs and outputs of matter and energy (most environmental systems)

dynamic equilibrium

when opposing forces, or inputs and outputs, are balanced, the system is said to be in a state of dynamic equilibrium. If one element changes due to external influence, it upsets the equilibrium and affects the other components

positive feedback

a cyclical sequence of events where the initial change is amplified

negative feedback

a cyclical sequence of events where the initial change is neutralised

positive feedback example

warmer land increases microbial activity in soils, which releases CO2. More CO2 in the atmosphere leads to a warmer climate, further increasing microbial activity

negative feedback example

increased plant productivity due to higher CO2 levels. More plants and growth lead to more CO2 being taken from the atmosphere during photosynthesis

why is it important to understand the global stores of water and carbon?

• so we can protect them and don't fully deplete them

• so we can use them (eg fossil fuels)

• to understand how they are linked and could affect each other

global stores of water

oceanic water cryosphere (stored as ice) lithosphere (groundwater, lakes, rivers etc) atmosphere (mainly water vapour) pedosphere (soils)

hydrosphere definition

a discontinuous layer of water at or near the Earth's surface (including all liquid and frozen surface waters, groundwater and atmospheric water vapour)

global stores of carbon

lithosphere (crust and upper mantle) biosphere (living things) hydrosphere (water, mainly oceans) atmosphere pedosphere (soil)