Environment | Insight Maker

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

Simple model to illustrate an annual cycle for phytoplankton biomass in temperate waters.
Potential primary production uses Steele's equation and a Michaelis-Menten (or Monod) function for nutrient limitation. Respiratory losses are only a function of biomass.

Clone of Phytoplankton model URI

Sara Gomes

This model describes the N isotope dynamics in a marine system where the shallowness of the chemocline prevents significant nitrification near the base of the photic zone.

N isotope dynamics in a suboxic Paleozoic water column

Michael Tuite

The Logistic Map is a polynomial mapping (equivalently, recurrence relation) of degree 2, often cited as an archetypal example of how complex, chaotic behaviour can arise from very simple non-linear dynamical equations. The map was popularized in a seminal 1976 paper by the biologist Robert May, in part as a discrete-time demographic model analogous to the logistic equation first created by Pierre François Verhulst.

Mathematically, the logistic map is written

where:

is a number between zero and one, and represents the ratio of existing population to the maximum possible population at year n, and hence x0 represents the initial ratio of population to max. population (at year 0)r is a positive number, and represents a combined rate for reproduction and starvation. To generate a bifurcation diagram, set 'r base' to 2 and 'r ramp' to 1
To demonstrate sensitivity to initial conditions, try two runs with 'r base' set to 3 and 'Initial X' of 0.5 and 0.501, then look at first ~20 time steps

Clone of Clone of The Logistic Map

Aaron Bouchard

This model illustrates predator prey interactions using real-life data of wolf and moose populations on the Isle Royale. It was "cloned" from a model that InsightMaker provides to its users, at
https://insightmaker.com/insight/2068/Isle-Royale-Predator-Prey-Interactions
Thanks Scott Fortmann-Roe.

I've created a Mathematica file that replicates the model, at
http://www.nku.edu/~longa/classes/2018spring/mat375/mathematica/Moose-n-Wolf-InsightMaker.nb

It allows one to experiment with adjusting the initial number of moose and wolves on the island.

I used steepest descent in Mathematica to optimize the parameters, with my objective data being the ratio of wolves to moose. You can try my (admittedly) kludgy code, at
http://www.nku.edu/~longa/classes/2018spring/mat375/mathematica/Moose-n-Wolf-InsightMaker-BestFit.nb

{WolfBirthRateFactorStart,
WolfDeathRateStart,
MooseBirthRateStart,
MooseDeathRateFactorStart,
moStart,
woStart} =
{0.000267409,
0.239821,
0.269755,
0.0113679,
591,
23.};

Clone of Isle Royale: Predator/Prey Model for Moose and Wolves

Allison Zembrodt

The time-variable solution to a step-function change in inflow concentration for an ideal, completely mixed lake.

Clone of Clone of Clone of ENVE 431 - HW5 - PROBLEM 7

Anna Messing

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

Fooodwaste happens everywhere and in every part of the food cycle even if nobody wants it to happen.

We created a local solution to reduce the waste. This solution is situated in Belgium (Kotrijk) where an exchange system (for services) already exists and it is called letsleie http://www.letsleie.be. We did choose letstlei because their exchange system doesn’t work with money but with a fictive money system "vlasbloemen". In their system we want to integrate the exchange of food leftovers. After some years the system could become world wide.

Our solution begins with an event in a neighbourhood or apartments. This event brings the neighbours together who don't know each anymore. It explains the existing system and the problems of the food waste. Every person had to take a leftover and chefs will create a delicious meal of it. The members will receive a food box who is biodegradable and contains a QR code that will simplify the food/ service exchange.

People will talk to each other after the event and more and more people will join without needing new publicity.

Foodwaste Reducing by exchanging

DESTREBECQ

This stock and flow diagram is a 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 shallow lake

mereana wilson

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 Oyster Growth based on Phytoplankton Biomass

Francisco Xavier

jute bag project: prototype

Shweta Rastogi

Lynx vs Hares

Ivan Pešić

How the 4-H club became a marketing thingy for DuPont

Clone of 4-H impact on African Farming

Nautk

European Masters in System Dynamics 2016
New University of Lisbon, Portugal

Simple model to represent oyster individual growth by simulating feeding and metabolism.

EMSD 2016

Joao G. Ferreira

12

Second Draft

Koala Population Dynamic Systems

Ty

This story presents a conceptual model of nitrogen 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.

Clone of Story of nitrogen dynamics in a shallow lake

Duncan Golicher

Ce modèle est une simulation classique du cycle de productivité dans l'océan, incluant les effets de la thermocline pour désactiver l'advection d'éléments nutritifs dissous et de détritus à la couche superficielle.

Ce modèle illustre un certain nombre de caractéristiques intéressantes notamment le lien de trois variables d'état dans un cycle fermé, l'utilisation du temps pour contrôler la durée de l'advection et la fonction modulus pour les données de température qui cyclent annuellement sur plusieurs années.

Les variables d'état du modèle sont exprimées en unités d'azote (mg N m-3), et l'étalonnage est basé sur:

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.

Traduction du modèle de Joao G Ferreira (https://insightmaker.com/insight/6838/NPD-model-Nutrients-Phytoplankton-Detritus)

Le modèle NPD (nutriments, phytoplancton, détritus) basé sur la productivité primaire de la Mer du Nord - CHANGEMENT TEMPERATURE 1 DEGRE

Alexia Parhas

•Dry Period Case

– 25 years of historical dry period on record (1947-1973)-including drought of record (1947-1956)

–Represents the dry period case

–Future dry cycle includes dry cycle of AMO and overlay of IPCC climate change predictions

Clone of Clone of EA dry conditions 1947-1973

David Anderson

Carbon Cycle

Liz

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

Rhino poaching in South - Africa

Anneli Ritzell

A simulation illustrating simple predator prey dynamics. You have two populations.

L&I4: Predator Prooi

MK Biologie

Clone of Clone of Group 1 Project

Cassidy Mellott

This model describes nitrogen 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 reduce the stock at which they start and add to the stock at which they end.

Clone of Story of nitrogen dynamics in a shallow lake

Caleb Jacob Coffey

Environment Models