Insight diagram
Ecology Hudson River Estuary Environment Material Transfer
Material/Energy Transfer in the Hudson River Estuary
Angelo Rivas
Two households with PV systems and electric vehicles sharing a battery and connected to the grid. What are the advantages? This model prototypes the working of an Smart Grid with Electric Vehicles The objective is testing the theoretical advantages of batteries (also batteries in Electric Vehicle
Energy Environment Electric Vehicles Renewable Energies Home Storage
Two households with PV systems and electric vehicles sharing a battery and connected to the grid. What are the advantages?

This model prototypes the working of an Smart Grid with Electric Vehicles

The objective is testing the theoretical advantages of batteries (also batteries in Electric Vehicles) in combination with renewable energies. The model considers two houses, that store energy both in Electric Vehicles (Vehicle to Grid), and in a communal battery.

Except when specified otherwise, the units of all variables are expressed in W/h.

Press "Story" in the lower bar for a guided tour over the model. Better seen at 50% zoom.

by Carlos Varela (cvarela@gmx.at)
Clone of Vehicle to Grid Simulation
Ida Mannoh
Modeling forest succession in a northeast deciduous forest.
Succession Ecology Environment
Modeling forest succession in a northeast deciduous forest.
Lab1 Forestry Succession Model
Owen Stuart
6
Insight diagram
Cleanliness Environment Beggary Jute Bag Recycling
jute bag project: prototype
Shweta Rastogi
Simple model to illustrate oyster growth based on primary production of Phytoplankton as a state variable, forced by light and nutrients, running for a yearly period. Phytoplankton growth based on on Steele's and Michaelis-Menten equations), where:  Primary Production=(([Pmax]*[I]/[Iopt]*exp(1-[I]
Phytoplankton Bivalves Environment Primary Production Growth
Simple model to illustrate oyster growth based on primary production of Phytoplankton as a state variable, forced by light and nutrients, running for a yearly period.

Phytoplankton growth based on on Steele's and Michaelis-Menten equations), where: 

Primary Production=(([Pmax]*[I]/[Iopt]*exp(1-[I]/[Iopt])*[S])/([Ks]+[S]))

Pmax: Maximum production (d-1)
I: Light energy at depth of interest (uE m-2 s-1)
Iopt: Light energy at which Pmax occurs (uE m-2 s-1)
S: Nutrient concentration (umol N L-1)
Ks: Half saturation constant for nutrient (umol N L-1).

Further developments:
- Nutrients as state variable in cycle with detritus from phytoplankton and oyster biomass.
- Light limited by the concentration of phytoplankton.
- Temperature effect on phytoplankton and Oyster growth.


Clone of Clone of Oyster Growth based on Phytoplankton Biomass
Joana Ferreira Cardoso
23
Life and Death
Animals Environment
Life and Death
Clone of Mooses & Wolves
ribal awad
In Chile, 60% of its population are exposed to levels of Particulate Matter (PM) above international standards . Air Pollution is causing 4,000 premature deaths per year , including health costs over US$8 billion. The System Dynamics Causal Loop Diagram developed herein shows an initial study o
Heating Environment Air Pollution
In Chile, 60% of its population are exposed to levels of Particulate Matter (PM) above international standards. Air Pollution is causing 4,000 premature deaths per year, including health costs over US$8 billion.

The System Dynamics Causal Loop Diagram developed herein shows an initial study of the dynamics among the variables that influences the accumulation of PM in the air, in particular the case of Temuco, in the South of Chile. In Temuco, 97% of the PM inventories comes from the combustion of low quality firewood, which in turns is being burned due to its low price and cultural habits/tradition.
Clone of Air Pollution Dynamics - Firewood Combustion
David Bonin
This stock and flow diagram is an updated working draft of a conceptual model of a dune-lake system in the Northland region of New Zealand.
Environment Nutrient Cycling Lake Management Leaching

This stock and flow diagram is an updated working draft of a conceptual model of a dune-lake system in the Northland region of New Zealand.

Clone of Stock and flow diagram of phosphorus in a lake
Caleb Jacob Coffey
7
Simulates Ag biogeochemical cycling using data from Rauch and Pacyna (2009). This Insight forms part of the engaged lear​ning exercise for a SESYNC case study about the human relationship with silver as a natural resource throughout history.
Case Study Geoscience Environment
Simulates Ag biogeochemical cycling using data from Rauch and Pacyna (2009). This Insight forms part of the engaged lear​ning exercise for a SESYNC case study about the human relationship with silver as a natural resource throughout history.
Silver Biogeochemical Cycling v2
Meghan Wagner
307
For Sustainability & Eco Innovation class
Sports Environment
For Sustainability & Eco Innovation class
Clone of Clone of The Olympics Stock & Flow + Stakeholders
Nhan Dung
C
Prey Environment Ecology Predator
C
Predator-Prey Interactions (Wolf & Moose) QC
Josh Kruhm
B
Environment Prey Predator Ecology
B
Predator-Prey Interactions (Wolves & Moose) QB
Josh Kruhm
Marine plastic is rapidly increasing due to increasing production and use of plastic in all economic activities, short use times and long life times of plastic, and large mismanagement of plastic waste. With this, the threat plastic poses to the marine biosphere is also increasing and will continue
Environment Plastic
Marine plastic is rapidly increasing due to increasing production and use of plastic in all economic activities, short use times and long life times of plastic, and large mismanagement of plastic waste. With this, the threat plastic poses to the marine biosphere is also increasing and will continue to increase over a long time into the future. Risk knowledge is limited and risk perception and awareness are not resulting in significant mitigation efforts. The case study will aim at modeling the use and life cycles of plastic and the transport paths that lead to plastic entering the ocean. The models will be used to simulate possible futures based on a scenario approach. The results of these efforts will be visualized with the goal to increase risk awareness.
Group Plastics Model
Gregory Michael Joern
THE 2018 MODEL (BY GUY LAKEMAN) EMPHASIZES THE PEAK IN POLLUTION BEING CREATED BY OVERPOPULATION. WITH THE CARRYING CAPACITY OF ARABLE LAND NOW BEING 1.5 TIMES OVER A SUSTAINABLE FUTURE (PASSED IN 1990) AND NOW INCREASING IN LOSS OF HUMAN SUSTAINABILITY DUE TO SEA RISE AND EXTREME GLOBAL WATER R
Death Strategy Engineering Technology Science Mortality Energy Failure Climate Economics Weather Politics Fertility Population Population Growth Demographics Environment Health Services Resources Land Jobs Labor Urban Industrial Rural Lifetime Pollution Regeneration Yield Ocean Sea Fish Plants Animals Flood Drought Loss Hurricane Typhoon Tornado Cyclone Agriculture Transport Silicene Graphene Resource Solar Food Nuclear

THE 2018 MODEL (BY GUY LAKEMAN) EMPHASIZES THE PEAK IN POLLUTION BEING CREATED BY OVERPOPULATION.
WITH THE CARRYING CAPACITY OF ARABLE LAND NOW BEING 1.5 TIMES OVER A SUSTAINABLE FUTURE (PASSED IN 1990) AND NOW INCREASING IN LOSS OF HUMAN SUSTAINABILITY DUE TO SEA RISE AND EXTREME GLOBAL WATER RELOCATION IN WEATHER CHANGES IN FLOODS AND DROUGHTS AND EXTENDED TROPICAL AND HORSE LATTITUDE CYCLONE ACTIVITY AROUND HADLEY CELLS

The World3 model is a detailed simulation of human population growth from 1900 into the future. It includes many environmental and demographic factors.

THIS MODEL BY GUY LAKEMAN, FROM METRICS OBTAINED USING A MORE COMPREHENSIVE VENSIM SOFTWARE MODEL, SHOWS CURRENT CONDITIONS CREATED BY THE LATEST WEATHER EXTREMES AND LOSS OF ARABLE LAND BY THE  ALBEDO EFECT MELTING THE POLAR CAPS TOGETHER WITH NORTHERN JETSTREAM SHIFT NORTHWARDS, AND A NECESSITY TO ACT BEFORE THERE IS HUGE SUFFERING.
BY SETTING THE NEW ECOLOGICAL POLICIES TO 2015 WE CAN SEE THAT SOME POPULATIONS CAN BE SAVED BUT CITIES WILL SUFFER MOST. 
CURRENT MARKET SATURATION PLATEAU OF SOLID PRODUCTS AND BEHAVIORAL SINK FACTORS ARE ALSO ADDED

Use the sliders to experiment with the initial amount of non-renewable resources to see how these affect the simulation. Does increasing the amount of non-renewable resources (which could occur through the development of better exploration technologies) improve our future? Also, experiment with the start date of a low birth-rate, environmentally focused policy.

2018 OVERPOPULATION LEADS TO POLLUTION based on Weather & Climate Extreme Loss of Arable Land and Ocean Fertility by Guy Lakeman - The World3+ Model: Forecaster
Guy Lakeman
24
European Masters in System Dynamics 2016 New University of Lisbon, Portugal  Model to represent oyster individual growth by simulating feeding and metabolism. Builds on the core model in three ways: (i) partitions metabolic costs into feeding and fasting catabolism; (ii) adds allometry to clearance
Environment Aquaculture
European Masters in System Dynamics 2016
New University of Lisbon, Portugal

 Model to represent oyster individual growth by simulating feeding and metabolism. Builds on the core model in three ways: (i) partitions metabolic costs into feeding and fasting catabolism; (ii) adds allometry to clearance rate; (iii) adds temperature dependence to clearance rate.
EMSD 2016 full
Joao G. Ferreira
7
Primitives for Watershed modeling project. Click Clone Insight at the top right to make a copy that you can edit.
Rainwater Water Environment
Primitives for Watershed modeling project. Click Clone Insight at the top right to make a copy that you can edit.
Primitives for Rainwater Harvesting ENVS 270 S21
Rivka Fidel
231
The World Socio-Economics model is computer model to simulate the consequence of interactions between the earth and human systems based on the World3 model by the work of Club of Rome, The Limits to Growth[1]. The World3 model builds by system dynamics theory that is has an approach to underst
Sustainability Environment
The World Socio-Economics model is computer model to simulate the consequence of interactions between the earth and human systems based on the World3 model by the work of Club of Rome, The Limits to Growth[1].

The World3 model builds by system dynamics theory that is has an approach to understanding the nonlinear behaviour of complex systems over time using stocks, flows, feedback loops, table functions and time delays.

The Limits to Growth concludes that, without substantial changes in resource consumption, "the most probable result will be a rather sudden and uncontrollable decline in both population and industrial capacity". 

Since the World3 model was originally created, it has had minor tweaks to get to the World3-91 model used in the book Beyond the Limits[2], later improved to get the World3-03 model used in the book Limits to Growth: the 30 year update[3].

References;
[1] Meadows, Donella H., Meadows, Dennis L., Randers, Jørgen., Behrens III, William W (1972). The Limits to Growth. 

[2] Meadows, Donella H., Dennis L. Meadows, Randers, Jørgen., (1992). Beyond the limits: global collapse or a sustainable future.

[3] Meadows, Dennis., Randers, Jørgen., (2004). The limits to growth: the 30-year update.
Clone of World Socio-Economics model 2000-2100
Nathan LB
Very simple model demonstrating growth of phytoplankton using Steele's equation for potential production and Michaelis-Menten equation for nutrient limitation. Both light and nutrients (e.g. nitrogen) are modelled as forcing functions, and the model is "over-calibrated" for stability. The phytopla
Environment Phytoplankton Shellfish
Very simple model demonstrating growth of phytoplankton using Steele's equation for potential production and Michaelis-Menten equation for nutrient limitation.

Both light and nutrients (e.g. nitrogen) are modelled as forcing functions, and the model is "over-calibrated" for stability.

The phytoplankton model approximately reproduces the spring-summer diatom bloom and the (smaller) late summer dinoflagellate bloom.
 
Oyster growth is modelled only as a throughput from algae. Further developments would include filtration as a function of oyster biomass, oyster mortality, and other adjustments.
Clone of Simple phytoplankton and oyster model
Eduardo
This model illustrates predator prey interactions using real-life data of wolf and moose populations on the Isle Royale. We incorporate logistic growth into the moose dynamics, and we replace the death flow of the moose with a kill rate modeled from the kill rate data found on the Isle Royale websi
Ecology Populations Midterm Environment
This model illustrates predator prey interactions using real-life data of wolf and moose populations on the Isle Royale.

We incorporate logistic growth into the moose dynamics, and we replace the death flow of the moose with a kill rate modeled from the kill rate data found on the Isle Royale website.

I start with these parameters:
Wolf Death Rate = 0.15
Wolf Birth Rate = 0.0187963
Moose Birth Rate = 0.4
Carrying Capacity = 2000
Initial Moose: 563
Initial Wolves: 20

I used RK-4 with step-size 0.1, from 1959 for 60 years.

The moose birth flow is logistic, MBR*M*(1-M/K)
Moose death flow is Kill Rate (in Moose/Year)
Wolf birth flow is WBR*Kill Rate (in Wolves/Year)
Wolf death flow is WDR*W

Clone of Final Midterm Student version of A More Realistic Model of Isle Royale: Predator Prey Interactions
Donna Odhiambo
Demonstration of excretion vs immobilization as function of feedstock C:N
Ecosystem Environment Nutrient
Demonstration of excretion vs immobilization as function of feedstock C:N
Clone of C:N-bacteria-DOM
Amanda Freele
This model illustrates predator prey interactions using real-life data of wolf and moose populations on the Isle Royale. We incorporate logistic growth into the moose dynamics, and we replace the death flow of the moose with a kill rate modeled from the kill rate data found on the Isle Royale websi
Ecology Populations Environment Midterm
This model illustrates predator prey interactions using real-life data of wolf and moose populations on the Isle Royale.

We incorporate logistic growth into the moose dynamics, and we replace the death flow of the moose with a kill rate modeled from the kill rate data found on the Isle Royale website.

I start with these parameters:
Wolf Death Rate = 0.15
Wolf Birth Rate = 0.0187963
Moose Birth Rate = 0.4
Carrying Capacity = 2000
Initial Moose: 563
Initial Wolves: 20

I used RK-4 with step-size 0.1, from 1959 for 60 years.

The moose birth flow is logistic, MBR*M*(1-M/K)
Moose death flow is Kill Rate (in Moose/Year)
Wolf birth flow is WBR*Kill Rate (in Wolves/Year)
Wolf death flow is WDR*W

Clone of Midterm - Hollings Type III Model
Maria E Ruwe
The following insight shows the level of crime in the town of Bourke in comparison to the levels of Police and Community Engagement
Engagement Environment Youth Crime Marketing
The following insight shows the level of crime in the town of Bourke in comparison to the levels of Police and Community Engagement
Clone of Crime vs. Engagement
Brett Ely
This model describes phosphorus cycling in a dune-lake system in the Northland region of New Zealand. It is based on stock and flow diagrams where each orange oval represents an input, while each blue box represents a stock. Each arrow represents a flow. Flows involve a loss from the stock at which
Environment Nutrient Cycling Management Lake Leaching

This model describes phosphorus cycling in a dune-lake system in the Northland region of New Zealand. It is based on stock and flow diagrams where each orange oval represents an input, while each blue box represents a stock. Each arrow represents a flow. Flows involve a loss from the stock at which they start and add to the stock at which they end.

Clone of Story of phosphorus dynamics in a shallow lake
Caleb Jacob Coffey
3
This model is a classic simulation of the production cycle in the ocean, including the effects of the thermocline in switching off advection of dissolved nutrients and detritus to the surface layer. It illustrates a number of interesting features including the coupling of three state variables in a
Phytoplankton Environment Primary Production Biogeochemistry Ocean
This model is a classic simulation of the production cycle in the ocean, including the effects of the thermocline in switching off advection of dissolved nutrients and detritus to the surface layer.

It illustrates a number of interesting features including the coupling of three state variables in a closed cycle, the use of time to control the duration of advection, and the modulus function for cycling annual temperature data over multiple years.

The model state variables are expressed in nitrogen units (mg N m-3), and the calibration is based on:

Baliño, B.M. 1996. Eutrophication of the North Sea, 1980-1990: An evaluation of anthropogenic nutrient inputs using a 2D phytoplankton production model. Dr. scient. thesis, University of Bergen.
 
Fransz, H.G. & Verhagen, J.H.G. 1985. Modelling Research on the Production Cycle of Phytoplankton in the Southern Bight of the Northn Sea in Relation to Riverborne Nutrient Loads. Netherlands Journal of Sea Research 19 (3/4): 241-250.

This model was first implemented in PowerSim some years ago by one of my M.Sc. students, who then went on to become a Buddhist monk. Although this is a very Zen model, as far as I'm aware, the two facts are unrelated.
Clone of NPD model (Nutrients, Phytoplankton, Detritus)
Diana Cristina Cardona Duque