Quick guide on how to read our data

This is a quick guide describing our main metrics. To get a more comprehensive understanding of how we monitor and report on internal displacement, please visit our “About our data” page.  

Defining internal displacement 

Internal displacement refers to the forced movement of people within the country they live in. IDMC adopts the definition of an internally displaced person (IDP) categorised in the Guiding Principles on Internal Displacement

Internally displaced persons are persons or groups of persons who have been forced or obliged to flee or to leave their homes or places of habitual residence, in particular as a result of or in order to avoid the effects of armed conflict, situations of generalized violence, violations of human rights or natural or human-made disasters, and who have not crossed an internationally recognized State border. 

For accounting purposes, we focus on these key elements of this definition when determining whom to include in our estimates: forced displacement; from their habitual residence; and without crossing an internationally recognized State border.  

Monitoring internal displacement 

We monitor events across the globe to identify instances of internal displacement. We use the most reliable sources of data from each context, including UN organizations and government agencies, local authorities, international and local NGOs, civil society and human rights organizations, media outlets and academia. One way we determine the reliability of our figures is to review the methodology used to collect the data and triangulate the information using several sources whenever necessary and possible. 

Measuring internal displacement 

We measure two main metrics, the number of internally displaced people and the number of internal displacements.  

Internally displaced people (IDPs) 

The number of IDPs is a snapshot of the total number of people living in internal displacement at a specific point in time in a specific location. For our Global Report on Internal Displacement (GRID) and the Global Internal Displacement Database (GIDD), we make these snapshots as of the end of each year. This number includes people uprooted within a year who have not been able to return home or find another solution to displacement, plus people who have been displaced in previous years and have not found a lasting solution.  

This figure illustrates the scale of displacement in a specific country and worldwide while also highlighting progress on solutions to internal displacement. Because the total number of IDPs includes people displaced in previous years and still living in internal displacement, the number can be higher than the number of new movements within a year.  

Internal displacements 

An internal displacement refers to each new forced movement of a person within the borders of the country of their habitual residence recorded during the year. The same person or people can be displaced several times over a given period before finding a solution to their displacement. We count each time a person is forced to move as an internal displacement. This figure illustrates dynamics of displacement in a specific crisis. 

Given the challenges in tracking population movements, it is difficult to determine what portion of internal displacements refer to people being displaced for the first time and what portion represents the same people being displaced a second, third, fourth or fifth time. As a result, internal displacements could include secondary or multiple displacement movements.  

The number of internal displacements within a specific year is usually higher than the increase in the number of internally displaced people from one year to another. The number of internal displacements includes movements of newly displaced people as well as repeated and multiple movements of people already living in displacement. 

Understanding the triggers of internal displacement 

We focus on internal displacement due to disasters and conflict and violence and do not track displacement due to human-rights violations, or human-made disasters. When monitoring displacement, any displacement is recorded as a displacement event triggered by conflict and violence or by disasters. Each group is broken down into types. 

Conflict and violence 

We track internal displacements triggered by conflict and violence, and try to disaggregate, to the extent possible, the type of violence that triggers displacement. This includes international armed conflict, non-international armed conflict, communal violence, crime-related violence, civilian-state violence and other forms of violence. Most often, we categorize each conflict-related displacement in line with the Rule of Law in Armed Conflicts online portal by the Geneva Academy of International Humanitarian Law and Human Rights. 


We group movements of people triggered by disasters into two categories: weather-related and geophysical. Based on EM-DAT, the international disaster database of the Centre for Research on the Epidemiology of Disasters, we categorize displacements according to more than 20 different hazard types. Weather-related displacements, for example, include hazards such as floods, droughts, landslides, storms – including cyclones and other storms –, wildfires and extreme temperatures. Geophysical displacements include, for example, earthquakes, volcanic eruptions and landslides.