Geography and environment#

The following parameters determine characteristics of the geography and environment of the simulation. For example, how to use the temperature or rainfall data in the climate files and the size of the nodes in the simulation.

Note

Parameters are case-sensitive. For Boolean parameters, set to 1 for true or 0 for false. Minimum, maximum, or default values of “NA” indicate that those values are not applicable for that parameter.

EMOD does not use true defaults; that is, if the dependency relationships indicate that a parameter is required, you must supply a value for it. However, many of the tools used to work with EMOD will use the default values provided below.

JSON format does not permit comments, but you can add “dummy” parameters to add contextual information to your files. Any keys that are not EMOD parameter names will be ignored by the model.

Parameter

Data type

Minimum

Maximum

Default

Description

Example

Base_Air_Temperature

float

-55

45

22

The air temperature, in degrees Celsius, where Climate_Model is set to CLIMATE_CONSTANT.

 
{
    "Climate_Model": "CLIMATE_CONSTANT",
    "Base_Air_Temperature": 30
}

Base_Land_Temperature

float

-55

60

26

The land temperature, in degrees Celsius, where Climate_Model is set to CLIMATE_CONSTANT.

 
{
    "Climate_Model": "CLIMATE_CONSTANT",
    "Base_Land_Temperature": 20
}

Base_Rainfall

float

0

150

10

The value of rainfall per day in millimeters when Climate_Model is set to CLIMATE_CONSTANT.

 
{
    "Climate_Model": "CLIMATE_CONSTANT",
    "Base_Rainfall": 20
}

Base_Relative_Humidity

float

0

1

0.75

The value of humidity where Climate_Model is set to CLIMATE_CONSTANT.

 
{
    "Base_Relative_Humidity": 0.1
}

Default_Geography_Initial_Node_Population

integer

0

1000000

1000

When using the built-in demographics for default geography, the initial number of individuals in each node. Note that the built-in demographics feature does not represent a real geographical location and is mostly used for testing. Enable_Demographics_Builtin must be set to true (1).

 
{
    "Enable_Demographics_Builtin": 1,
    "Default_Geography_Initial_Node_Population": 1000,
    "Default_Geography_Torus_Size": 3
}

Default_Geography_Torus_Size

integer

3

100

10

When using the built-in demographics for default geography, the square root of the number of nodes in the simulation. The simulation uses an N x N square grid of nodes with N specified by this parameter. If migration is enabled, the N x N nodes are assumed to be a torus and individuals can migrate from any node to all four adjacent nodes.

To enable migration, set Migration_Model to FIXED_RATE_MIGRATION. Built-in migration is a form of “local” migration where individuals only migrate to the adjacent nodes. You can use the x_Local_Migration parameter to control the rate of migration. The other migration parameters are ignored. Note that the built-in demographics feature does not represent a real geographical location and is mostly used for testing.

Enable_Demographics_Builtin must be set to true (1).

 
{
    "Enable_Demographics_Builtin": 1,
    "Default_Geography_Initial_Node_Population": 1000,
    "Default_Geography_Torus_Size": 3
}

Node_Grid_Size

float

0.00416

90

0.004167

The spatial resolution indicating the node grid size for a simulation in degrees.

 
{
    "Node_Grid_Size": 0.042
}