WOLFRAM SYSTEMMODELER

Scenario_1

1st Scenario

Diagram

Wolfram Language

In[1]:=
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SystemModel["SystemDynamics.WorldDynamics.World2.Scenario_1"]
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Information

This is the original scenario of Jay Forrester's WORLD2 model as described in his World Dynamics book.


References:

  1. Cellier, F.E. (1991), Continuous System Modeling, Springer-Verlag, New York, ISBN: 0-387-97502-0, 755p.
  2. Forrester, J.W. (1971), World Dynamics, Pegasus Communications, 160p.


Simulate the model across 200 years, and plot the state variables as well as the quality of life as functions of the calendar years:


Public Parameters (21)

Population_0

Value: 1650000000.0

Type: Real

Description: World population in 1900

Pollution_0

Value: 200000000.0

Type: Real

Description: Pollution in 1900

Nat_Resources_0

Value: 900000000000.0

Type: Real (ton)

Description: Unrecoverable natural resources in 1900

Cap_Invest_0

Value: 400000000.0

Type: Real (dollar)

Description: Capital investment in 1900

CIAF_0

Value: 0.2

Type: Real

Description: Proportion of capital investment in agriculture in 1900

BRN

Value: 0.04

Type: Real (¹/yr)

Description: Normal birth rate

CIAFN

Value: 0.3

Type: Real (dollar)

Description: CIAF normalization

CIAFT

Value: 15.0

Type: Real (yr)

Description: CIAF time constant

CIDN

Value: 0.025

Type: Real (dollar/yr)

Description: Normal capital discard

CIGN

Value: 0.05

Type: Real (dollar/yr)

Description: Normal capital generation

DRN

Value: 0.028

Type: Real (¹/yr)

Description: Normal death rate

ECIRN

Value: 1.0

Type: Real (dollar)

Description: Capital normalization

FC

Value: 1.0

Type: Real (kg/yr)

Description: Food coefficient

FN

Value: 1.0

Type: Real (kg/yr)

Description: Food normalization

Land_Area

Value: 135000000.0

Type: Real (hectare)

Description: Area of arable land

NRI

Value: 900000000000.0

Type: Real (ton)

Description: Initial natural resources

NRUN

Value: 1.0

Type: Real (¹/yr)

Description: Normal resource utilization

POLN

Value: 1.0

Type: Real (¹/yr)

Description: Normal pollution

POLS

Value: 3599900000.0

Type: Real

Description: Standard pollution

Pop_dens_norm

Value: 26.5

Type: Real (¹/hectare)

Description: Normal population density

QLS

Value: 1.0

Type: Real

Description: Standard quality of life

Outputs (6)

Pop

Type: Real

Description: World population

Pol

Type: Real

Description: Pollution

Pol_rat

Type: Real

Description: Pollution ratio

Cap_inv

Type: Real (dollar)

Description: Capital investment

Qual_life

Type: Real

Description: Quality of life

Nat_res

Type: Real (ton)

Description: Natural unrecoverable resources

Components (78)

Source1

Type: Source

Birth_Rate

Type: Rate_1

Population

Type: Level

Death_Rate

Type: Rate_1

Sink1

Type: Sink

Source2

Type: Source

Generation

Type: Rate_1

Natural_Resources

Type: Level

Depletion

Type: Rate_1

Sink2

Type: Sink

Gen_Const

Type: Const

BRMM

Type: Tabular

DRMM

Type: Tabular

BR_norm

Type: Gain

Prod_5_1

Type: Prod_5

DR_norm

Type: Gain

Prod_5_2

Type: Prod_5

BRFM

Type: Tabular

BRPM

Type: Tabular

BRCM

Type: Tabular

DRCM

Type: Tabular

DRPM

Type: Tabular

DRFM

Type: Tabular

Crowd_Rat

Type: Gain

NR_norm

Type: Gain

Prod_2_1

Type: Prod_2

NRMM

Type: Tabular

Source3

Type: Source

CI_Generation

Type: Rate_1

Capital_Investment

Type: Level

CI_Discard

Type: Rate_1

Sink3

Type: Sink

CIG_norm

Type: Gain

Prod_2_2

Type: Prod_2

CID_norm

Type: Gain

CIM

Type: Tabular

MSL

Type: Gain

NRFR

Type: Gain

ECIR

Type: Gain

Prod_3_1

Type: Prod_3

NREM

Type: Tabular

CIR

Type: Division

Source4

Type: Source

P_Generation

Type: Rate_1

Pollution

Type: Level

P_Absorption

Type: Rate_1

Sink4

Type: Sink

NotCIAF

Type: Linear

Pol_Ratio

Type: Gain

FCM

Type: Tabular

Prod_3_2

Type: Prod_3

Food_Ratio

Type: Gain

Source5

Type: Source

CIAFG

Type: Rate_1

CIAF

Type: Level

CIAFD

Type: Rate_1

Sink5

Type: Sink

CIAF_D

Type: Gain

CIAF_G

Type: Gain

Prod_2_3

Type: Prod_2

P_Abs

Type: Division

Pol_norm

Type: Gain

Prod_2_4

Type: Prod_2

POLCM

Type: Tabular

POLAT

Type: Tabular

CFIFR

Type: Tabular

FPM

Type: Tabular

Prod_2_5

Type: Prod_2

CIRA

Type: Gain

FPCI

Type: Tabular

CIQR

Type: Tabular

QLMF

Type: Division

QLM

Type: Tabular

QLF

Type: Tabular

Prod_4_1

Type: Prod_4

QLC

Type: Tabular

QLP

Type: Tabular

Quality_of_Life

Type: Gain