GEOS1701 Environmental Systems, Processes and Issues - Lecture 1 Notes
Course Themes
Understanding physical environments and the processes that form and modify them (Physical Geography, Climatology, and Biogeography).
Introduce range of environmental management issues by examining the nature of interactions between humans and physical environmental systems (Environmental Science).
Introduce methods used in monitoring and mitigating environmental hazards and change (Environmental Management and Remote Sensing).
Focus on Australian and global examples.
A Short History of Screw Ups
Stage 1: Hunters & Gatherers (> 12,000 years ago)
Overall impact limited and local.
Examples: Fire, stampeding animals.
Effects: Forests to grasslands, extinctions.
Stage 2: Agricultural Society (10,000 years ago)
Activities: Land clearing, irrigation, use of marginal land, mining of ore.
Effects: Soil erosion and land degradation (desertification), wastes.
Stage 3: Industrial Revolution (approx 250 years ago)
Shift from organic and common to inorganic and rare resources (e.g., wood to coal).
Impacts: Huge and immediate.
Environmental effects proliferated.
Local issues became regional/global.
Complexity, magnitude, and frequency of environmental issues are increasing.
Easter Island (Rapa Nui)
Illustrates the 'Tragedy of the Commons.'
Bad combination: Population increase + common/unmanaged resources.
The Shrinking of the Aral Sea
Example of environmental mismanagement where decision-makers didn't understand or care about the environment.
Human Interaction with and Transformation of the Environment
Has cascading effects.
Reasons for Environmental Mismanagement:
Religion
Cultural factors include Democracy and Industrialisation, Tragedy of the Commons, and ‘Frontierism’.
Biological Imperialism
Psychological and Economic factors such as ‘Growth is Good’.
Population and Food
Growing population (8 billion and rising) exacerbates environmental issues.
Nature 'Wins' Sometimes
Natural hazards and their management.
System Theory
System Definition: Any set of related objects or events and the inter-relationships between them linked by flows of energy and matter.
Reductionist Approach: Break the environment down into component parts to examine in detail.
Synthesis Approach: Put that information back together to understand “the big picture”.
Earth Systems: Comprise a set of physical, chemical, and biological systems that:
Are driven (forced) by energy.
Involve flows and transfer of matter.
Closed Systems: A system in which energy can enter or leave, but matter cannot.
Open Systems: A system in which there is an exchange of both energy and matter between the system and its surroundings.
Catchment System Example:
Includes inputs/outputs, flows/processes, stores, and feedback/regulation.
Components: precipitation, interception, evaporation, evapotranspiration, throughfall and stemflow, overland flow, infiltration, percolation, groundwater flow, channel runoff.
Equilibrium: Balance between inputs and outputs over time.
Static equilibrium
Steady state equilibrium
Stable equilibrium
Unstable equilibrium (thresholds)
Feedback: Describes changes or mechanisms in one part of the system that lead to change in another.
Negative Feedback: Resulting changes keep system in check (i.e., self-regulating behavior).
Positive Feedback: Changes result in greater changes, which may be gradual or cataclysmic.
The Morphodynamic Approach
Considers environmental conditions, sediments, geology, external forcing, sediment transport, morphology, stratigraphy, processes, and energy losses.
Time and Space Scales of Change:
Ocean waves: seconds-minutes-days
El Nino Southern Oscillation (ENSO): years to decades
Pacific Decadal Oscillation (PDO): decades to centuries
Ice Ages: millennia
Geological Time: millions of years
Morphodynamic Temporal and Spatial Scales
Addresses the scale cascade: space-time problem domains.
Approaches to Study
'Gurus'
Used explanatory description to identify landforms and infer evolution process.
Key figures: Charles ('Chuck') Lyell (Uniformitarianism, 1830), Charles ('L’il Chuck') Darwin (Coral Reefs, 1842), William Morris ('Chuckles') Davis (Cycle of Erosion, 1889).
Darwins’ theory of coral reef evolution
Sinking volcanic islands produce a sequence of fringing reefs to barrier reefs to atolls
Empirical Approach (post-WW 2)
Based on experiment and observation rather than theory.
Morphodynamic Approach (1970+)
Involves assessing landforms based on integrated process-form relationships.
Summary
Environmental issues are caused by both natural and anthropogenic causes.
An understanding of environmental systems and processes associated with these problems is necessary before appropriate responses can be adopted.
The behavior of ALL earth systems is dictated by various forms of equilibrium and feedback.
The morphodynamic approach is the best way to study physical systems over a variety of time and space scales.
This lecture presents extremely important content and concepts that provide the foundation for much of the material in the course.
Readings?
The Future Eaters by Tim Flannery
Silent Spring by Rachel Carson
Last Chance to See by Douglas Adams
Any old introductory Physical Geography or Environmental Science textbook will have an Introductory chapter similar to this lecture. Chapter 1 in Holden (2021) on the Course Reading list will also work!
Also have a look at this eBook in the UNSW Library: Imura, H. (2013) Environmental Systems Studies.
Review Questions
What does ‘tragedy of the commons’ mean, and how does it impact the environment?
What are some human factors that have led to the ‘mis-treatment’ of the environment?
Try and think of some examples of positive and negative feedback involving human interaction with the physical environment beyond those given in the lecture.
Explain what the morphodynamic approach is to studying physical environmental systems.
Why are spatial and temporal scales important in understanding the behavior of physical environmental systems?