# Data Dictionary

This document provides definitions for the data fields and values in the IFVI Value Factors dataset.

## Value Factor Structure

Each value factor in the dataset follows this general structure:

```json
{
  "Category": "String",         // Environmental impact category (e.g., "PM2.5", "SOx")
  "Location": "String",         // Geographic location (e.g., "Urban", "Rural")
  "Impact": "String",           // Impact type (e.g., "Primary Health", "Visibility")
  "Unit": "String",             // Measurement unit (e.g., "/metric ton", "/ha", "/kg")
  "ValueFactorKey": "String",   // Unique identifier for the value factor
  "ValueFactor": Number         // Monetary value in USD
}
```

## Categories

The dataset includes the following main categories of environmental impacts:

### Air Pollution
- **PM2.5**: Particulate matter with diameter less than 2.5 micrometers
- **SOx**: Sulfur oxides
- **NOx**: Nitrogen oxides
- **NH3**: Ammonia
- **VOC**: Volatile organic compounds

### Land Use and Conversion
- **Agricultural Land Types**: Various types of agricultural land (e.g., "Wheat - conventional", "Oilseeds - conventional")
- **Forestry**: Forest land
- **Urban Land Types**: Various types of urban land (e.g., "Paved", "Built")

### Waste
- **Hazardous**: Hazardous waste
- **Non-Hazardous**: Non-hazardous waste

### Water Pollution
- **Water Consumption**: Water usage and pollution impacts

## Locations

Locations in the dataset can refer to:
- Geographic settings (e.g., "Urban", "Rural", "Peri-Urban")
- Specific usage contexts (e.g., "Transport", "Industry")
- "N/A" for categories where location is not applicable

## Impacts

Impact types include:
- **Primary Health**: Direct health effects on humans
- **Visibility**: Effects on visibility
- **Lost Ecosystem Services**: Degradation of ecosystem services
- **Leachate**: Contamination from waste leachate
- **Waste Air Pollution**: Air pollution from waste
- **Heavy Metals and Dioxins**: Contamination by heavy metals and dioxins
- **Disamenity**: Reduction in amenity value
- **Waste GHGs**: Greenhouse gas emissions from waste

## Units

Units in the dataset include:
- **/metric ton**: Per metric ton of emissions (for air pollutants)
- **/ha**: Per hectare (for land use)
- **/kg**: Per kilogram (for waste)
- **/m³**: Per cubic meter (for water)

## Territories

The dataset covers 268 territories, including:
- Sovereign nations
- Dependencies
- US states (for air pollution data)

## Value Factor Calculation

Value factors are calculated based on IFVI methodologies that consider:
- Local economic conditions
- Population density
- Environmental sensitivity
- Health impacts
- Ecosystem service valuation

For detailed methodology information, refer to the IFVI documentation at [https://ifvi.org/methodology/environmental-topic-methodology/interim-methodologies/](https://ifvi.org/methodology/environmental-topic-methodology/interim-methodologies/).