Owens Lake Mono Lake, 1981 •Example of a relatively small system is Mono Lake in California Page 26-28 -Terminal lake -Brine shrimp, alkali fly, algae, migrating birds -Answer Check point questions, pg. 28 (pictures from Wikipedia)
Owens Lake
Mono Lake, 1981
•Example of a relatively small
system is Mono Lake in California
Page 26-28
-Terminal lake
-Brine shrimp,
alkali fly, algae,
migrating birds
-Answer Check point questions, pg. 28
(pictures from Wikipedia)
System Analysis
Environmental Science
Mr. Schisel
•System Analysis
•making observations of the inputs,
outputs, and changes in a system under
various conditions
• inputs: additions to a system
•outputs: losses from a system
•Steady States
•is when inputs = outputs
•the system does not change over
time
•Feedbacks
•adjustments in input or output rates
caused by changes to a system
•2 kinds of feedbacks:
negative feedback loops
positive feedback loops
•Negative Feedback Loops
•when a system responds to a change by
turning back to its original state
or
• the reduction in the rate at which the
system is changing
http://ecoplexity.org/model_feedback
•Example of a Negative Feedback Loop
• Imagine you are out walking in the country. As you
walk, the sun rises higher
in the sky and the air temperature increases. Your
body senses that your internal temperature is rising
above 370C and you start to sweat, which reduces
your body temperature by evaporating water from
your skin, returning your temperature to normal
http://www.slideshare.net/quercuscymru/overview-of-environmental-systems
•Positive Feedback Loop
•when change in a system is
amplified
•Hypothermia
Decomposition
•The health of many
environmental systems
depends on the proper
operation of feedback loops.
•Passage of Time
Natural systems are also affected by the passage
of time.
http://geology.com/records/sahara-desert-map.shtml
http://enviro-map.com/sahara-desert-map
http://knowledge.allianz.com/climate/impacts/?621/green-sahara-how-climate-change-transformed-the-desert
•EcoTipping Point
• An EcoTipping Point is a lever that reverses
environmental decline, setting in motion restoration
and sustainability.
• View the following video identify the positive
feedback loops and the negative feedback loops in
Rainwater Harvesting (Rajasthan, India).
http://www.youtube.com/watch?v=DG2DtF_mWww&feature=youtu.be
•Feedback Loops &
Tipping Points:
• Feedback loops are the key to how EcoTipping
Points work. EcoTipping Points set in motion a
cascade of effects that reverse the vicious
cycles responsible for environmental decline.
• An example of this can be found on
pages 52-55 in your book. Read your book
and complete the worksheet.