1.2 - Sytems And Models Flashcards
What does the term systems approach mean
used to describe a method of simplifying and understanding a complicated set of interactions
What could systems and interactions be
Systems, and the interactions they contain, may be environmental or ecological (e.g. the water cycle or predator-prey relationships), social (e.g. how we live and work) or economic (e.g. financial transactions or business deals)
What does the interactions within a system produce
The interactions within a system, when looked at as a whole, produce the emergent properties of the system
For example, in an ecosystem, all the different ecological interactions occurring within it shape how that ecosystem looks and behaves - if the interactions change for some reason (e.g. a new predator is introduced), then the emergent properties of the ecosystem will change too
What are the 2 main ways of studying systems
A reductionist approach involves dividing a system into its constituent parts and studying each of these separately - this can be used to study specific interactions in great detail but doesn’t give the overall picture of what is occurring within the system as a whole
A holistic approach involves looking at all processes and interactions occurring within the system together, in order to study the system as a whole
What are some examples of interactions between factors in the case of sustainability or sustainable development
These include environmental, social and economic factors (sometimes referred to as the three pillars of sustainability
A systems approach is required in order to understand how these different factors combine and interact with one another, as well as how they all work together as a whole (the holistic approach)
What is a system comprised of
Storages and flows
What does a flow provide
The flows provide inputs and outputs of energy and matter
What are the 2 process of a flow
- transfers (change in location)
- transformations (a change in the chemical nature)
Define transfer
Transfers are the movement of matter or energy from one component of the system to another, without any change in form or quality
- For example, water flowing from a river to a lake is a transfer
Define transformation
Transformations, on the other hand, involve a change in the form or quality of matter or energy as it moves through the system
- For example, when sunlight is absorbed by plants, it is transformed into chemical energy through the process of photosynthesis
How are transfers and transformations represented in a systems diagram
Transfers and transformations are often represented in systems diagrams by arrows that connect the different components of the system
- Arrows that represent transfers are usually labeled with the quantity of matter or energy being transferred (e.g., kg of carbon, kJ of energy), while arrows that represent transformations may include additional information about the process involved (e.g., photosynthesis, respiration)
What does the proccesses of systems diagram show
By understanding these processes, it is possible to identify opportunities to improve the efficiency or sustainability of the system
Do transfers and transformations occur at the same scale
Transfers and transformations can occur at different scales within a system, from the molecular level to the global level
- For example, at the molecular level, nutrients are transferred between individual organisms, while at the global level, energy is transferred between different biomes
How are storages represented of a systems diagram
Storages are commonly drawn as boxes
How are flows represented on a systems diagram,
Flows are commonly drawn as arrows
What are the three main types of systems
Open systems
Closed systems
Isolated systems
How do you determine the type of system
The category that a system falls into depends on how energy and matter flow between the system and the surrounding environment
What energy and matter exchange categorises a open system
Both energy and matter are exchanged between the system and it surrounding
Are open systems inorganic or organic
Open systems are usually organic (living) systems that interact with their surroundings (the environment) by taking in energy and new matter (often in the form of biomass), and by also expelling energy and matter (e.g. through waste products or by organisms leaving a system)
What is an example of a open system
- your body
- ecosystem
What energy and matter exchange categorises a closed system
Energy, but not matter, is exchanged between the system and its surroundings
Are closed systems organic or inorganic
Closed systems are usually inorganic (non-living), although this is not always the case
The International Space Station (ISS) could perhaps be seen as a closed system
It is a self-contained environment that must maintain a balance of resources, including air, water, and food, as well as waste management, energy production, and temperature control
The ISS cannot exchange matter with its surroundings
What type of system could the earth be classified as
The Earth (and the atmosphere surrounding it) could be viewed as a closed system
The main input of energy occurs via solar radiation
The main output of energy occurs via heat (re-radiation of infrared waves from the Earth’s surface)
Matter is recycled completely within the system
Although, technically, very small amounts of matter enter and leave the system (in the form of meteorites or spaceships and satellites), these are considered negligible
Artificial and experimental ecological closed systems can also exist - for example, sealed terrariums, containing just the right balance of water and living organisms (such as mosses, ferns, bacteria, fungi or invertebrates) can sometimes survive for many years as totally closed systems, if light and heat energy is allowed to be exchanged across the glass boundary
What is the energy and matter exchange in an isolated system
Neither energy nor matter is exchanged between the system and its surroundings
What is an example of an isolated system
Isolated systems do not exist naturally - they are more of a theoretical concept (although the entire Universe could be considered to be an isolated system)
What is a model
A model is a simplified version of reality
What is a model used to represent
model is often used to represent a system
The model can then be analysed or tested to learn more about how the system works and to predict how the system might respond to change
For example, weather models are used to predict how our weather systems change over time, allowing us to create weather forecasts
What are the 6 strengths of a model
- Models simplify complex systems
- Models allow predictions to be made about how systems will react in response to change
- System inputs can be changed to observe effects and outputs, without the need to wait for real-life events to occur
- Models are easier to understand than the real system
- Results from models can be shared between scientists, engineers, companies and communicated to the public
- Results from models can warn us about future environmental issues and how to avoid them or minimise their impact
What are the 6 limitations of a model
- Models can be oversimplified and inaccurate
- Results from models depend on the quality of the data inputs going into them
- Results from models become more uncertain the further they predict into the future
- Different models can show vastly different outputs even if they are given the same data inputs
- Results from models can be interpreted by different people in different ways
- Environmental systems are often incredibly complex, with many interacting factors - it is impossible to take all possible variables into account
