SYSTEMS

• what's a system?


  a set of interrelated components working together towards some kind of process
• open system


  allow energy and mass to pass across the system boundary.e.g Drainage Basin
• closed system

  allows energy but not matter across its system boundary. e.g carbon cycle as the amount of carbon on Earth stays the same
• positive feedback

  increasing effects of change
• negative feedback


  decreasing effects of change