Hudson River Estuary Food Web
This story contains a conceptual model of phosphorus cycling in a dune-lake system in the Northland region of New Zealand. It is based on the concept of a stock and flow diagram. Each orange ellipse represents an input, while each blue box represents a stock. Each arrow represents a flow. A flow involves a loss from the stock at which it starts and an addition to the stock at which it ends.
Story of phosphorus dynamics in a shallow lake
This model explains the mussel growth (Mytillus Edulis) based on primary production of phytoplankton biomass.
Light, nutrients and temperature were used as forcing functions over a two year period.
Mussel Growth based on Phytoplankton Biomass
Elements of Human Security
This model describes the flow of energy from generation to consumption for neighborhoods in the metro Atlanta area. It also calculates the cost of energy production and the number of years it will take to recover that cost.
Clone of Microgrid with storage
Primitives for Watershed modeling project. Click Clone Insight at the top right to make a copy that you can edit.
The converter in this file contains precipitation for Phoenix only.
Clone of Primitives for Rainwater Harvesting -Phoenix ENVS 270 F21
UDB 100 Assignment 1D
This simulation shows the drastic decline in the SEQ koala population due to various issues including human urban development, environmental issues, disease, habitat loss and domestic animals.
Koala Population in SEQ- Hayley Watts
FORCED GROWTH GROWTH GOES INTO TURBULENT CHAOTIC DESTRUCTION
BEWARE pushing increased growth blows the system!
(governments are trying to push growth on already unstable systems !)
The existing global capitalistic growth paradigm is totally flawed
The chaotic turbulence is the result of the concept and flawed strategy of infinite bigness this has been the destructive influence on all empires and now shown up by Feigenbaum numbers and Dunbar numbers for neural netwoirks
See Guy Lakeman Bubble Theory for more details on keeping systems within finite limited size working capacity containers (villages communities)
FORCED GROWTH INTO TURBULENCE
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 Clone of Air Pollution Dynamics - Firewood Combustion
Combining electromobility and renewable energies since 2014.
http://www.amsterdamvehicle2grid.nl/
Clone of Clone of Amsterdam V2G simulation 2.0
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)
Simple mass balance model for lakes based on the Vollenweider equation:
dMw/dt = Min - sMw + pMs - Mout
The model was first used in the 1960s to determine the phosphorus concentration in lakes and reservoirs for eutrophication assessment.
This version considers mercury, and adds diagenesis, using an extra state variable (mercury in the sediment), and incorporates desorption processes that release mercury trapped in the sediment back to the water column.
The temporal dynamics of the model simulate the typical development of pollution in time.
1. Low loading, low Hg concentration in lake
2. High loading, increasing Hg concentration in lake
3. Desorption rate is low, Hg in sediment increases
4. Measures implemented for source control, loading reduces
5. Hg in lake gradually decreases, but below a certain point, desorption increases, and lake Hg concentration does not improve
6. Recovery only occurs when the secondary load in the sediment is strongly reduced.
Clone of Mercury pollution model with diagenesis
Interplay between wolves eating sheep and farmers killing wolves who kill deer that eat crops that feed sheep.
Complex Sheep, Wolves, Deer, Crops
My AP Environmental Homework for the Cats Over Borneo Assignment
Taiga Food Web
Sagebrush Ecosystem- Cheatgrass Management
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
Westley, F. R., O. Tjornbo, L. Schultz, P. Olsson, C. Folke, B. Crona and Ö. Bodin. 2013. A theory of transformative agency in linked social-ecological systems. Ecology and Society 18(3): 27. link
Clone of Transformative Agency in Social-Ecological System
Interplay between wolves eating sheep and farmers killing wolves.
Sheep and Wolves
Simple (Kind of) food web of the Cane Toad Species. Includes different levels of consumers including predators.
Clone of Cane Toad Food Web
Interplay between wolves eating sheep and farmers killing wolves.
Simple Sheep and Wolves
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.
Oyster Growth based on Phytoplankton Biomass
This model shows the cycling of Mercury within a coastal wetland system. This cycling shows Elemental Mercury, Hg 2+, and Methylmercury within the soil, water, and air, and also interaction with the plants in the system.
Total wetland transpiration: 1.95x10^-5 m^3 m^-2 s^-1
Settling rate and resuspension units (%of settling): g m^-2 day^-1
Project 2 Wetland Mercury
The time-variable solution to a step-function change in inflow concentration for an ideal, completely mixed lake.
ENVE 431 - HW5 - PROBLEM 7
