Country intelligence page
Yemen YEM
Operation Yemen conflict at Admin 1. Every comparison below is confined to this operation, because operations differ in geographic scope, cadence and method and are not additive.
What changed?MOSAIC-derived
Comparing round 40 (01 Feb 2025) with round 39 (30 Sept 2023) inside the Yemen conflict operation. Thresholds are MOSAIC monitoring settings, not IOM categories.
Areas at or above +5 per cent momentum
| Area | Latest | Baseline | Change | Momentum | Comparability | Analysis |
|---|---|---|---|---|---|---|
| Al Maharah | 46,646 | 25,856 | +20,790 | +80.4% | Comparable | |
| Hadramaut | 100,745 | 89,660 | +11,085 | +12.4% | Comparable | |
| Shabwah | 51,290 | 45,881 | +5,409 | +11.8% | Comparable | |
| Marib | 1,792,022 | 1,605,960 | +186,062 | +11.6% | Comparable | |
| Taizz | 419,068 | 380,712 | +38,356 | +10.1% | Comparable | |
| Al Hudaydah | 134,893 | 127,133 | +7,760 | +6.1% | Comparable |
Methodology and provenance
- Source
- International Organization for Migration (IOM), Displacement Tracking Matrix (DTM). Public API v3.
- Endpoint
- /v3/displacement/admin1
- Geographic level
- Admin 1
- Operation
- Yemen conflict
- Reporting period
- 30 Sept 2023 to 01 Feb 2025
- Assessment round
- Round 40 compared with round 39
- Retrieved
- 2026-09-04T01:37:21.800Z
- Calculation
- Rows are summed to a present-IDP figure per area and round, then the latest round is compared with the preceding round of the same operation. Areas present in only one of the two rounds are reported as such and are never treated as zero.
Known limitations
- An area that disappears between rounds may have ceased to be assessed rather than ceased to host displacement.
- A newly reported area may be newly affected or newly assessed. The API does not distinguish between these.
- Threshold bands are MOSAIC monitoring settings and are not calibrated to this country's assessment cadence.
MOSAIC-derived indicator. Not an IOM classification.
National displacement timeline
Present IDPs by assessment round within the Yemen conflict operation. Breaks in the line mark non-consecutive round numbers, where an intervening round exists that this series does not include.
Methodology and provenance
- Source
- International Organization for Migration (IOM), Displacement Tracking Matrix (DTM). Public API v3.
- Endpoint
- /v3/displacement/admin1
- Geographic level
- Admin 1
- Operation
- Yemen conflict
- Reporting period
- 2015-07-30 to 2025-02-01
- Assessment round
- Round 40
- Retrieved
- 2026-09-04 01:37 UTC
- Calculation
- Present IDP figures are summed across all disaggregated source rows for each area, then across areas, for every round of the selected operation.
Known limitations
- Figures may be estimates derived from key informants and secondary sources rather than exact enumeration.
- Assessment coverage and cadence vary by country and operation, so cross-country comparison of change rates is not supported.
- A change in a recorded figure may reflect population movement, altered assessment coverage, changed access, or enumeration method, and the API does not distinguish between these.
- The public API exposes aggregated non-sensitive figures only, and does not carry the full detail of the underlying DTM datasets.
Admin 1 ranking, latest round
Areas ranked by present IDPs reported in the latest round. Bar length is proportional to the largest area.
- +11.6%Marib1,792,022
- +10.1%Taizz419,068
- +0.7%Aden303,053
- +6.1%Al Hudaydah134,893
- +12.4%Hadramaut100,745
- +0.8%Al Dhale'E78,044
- +3.8%Lahj66,910
- +11.8%Shabwah51,290
- +80.4%Al Maharah46,646
- -1.8%Abyan42,726
- +4.9%Al Jawf19,256
- -0.9%Socotra11,159
- -8.3%Al Bayda518
Methodology and provenance
- Source
- International Organization for Migration (IOM), Displacement Tracking Matrix (DTM). Public API v3.
- Endpoint
- /v3/displacement/admin1
- Geographic level
- Admin 1
- Operation
- Yemen conflict
- Reporting period
- 01 Feb 2025
- Assessment round
- Round 40
- Retrieved
- 2026-09-04 01:37 UTC
- Calculation
- Areas assessed in the latest round of this operation, ranked by summed present IDP individuals. Momentum shown alongside is the change from the preceding round.
Known limitations
- Only areas assessed in the latest round appear. An unassessed area is absent, not zero.
- Bar length encodes the reported figure only. It carries no information about area size, population or need.
MOSAIC-derived indicator. Not an IOM classification.
Anomaly signalsMOSAIC-derived
Areas whose latest figure moved unusually relative to their own recent history in this operation. Each signal names the rule that fired and the evidence behind it. A signal is a cue for collection, not a finding.
- MaribSustained multi-round increase
- Latest
- 1,792,022
- Baseline
- 1,605,960
- Magnitude
- 1.33
- Basis
- 14 obs, adequate
Three or more consecutive rounds of positive change, with cumulative growth of at least +25 per cent. Six or more observations available for the historical comparison.
- MaribDeviation from recent trend
- Latest
- 1,792,022
- Baseline
- 1,605,960
- Magnitude
- 40.33
- Basis
- 14 obs, adequate
The latest change exceeds 3.0 times the median absolute change of the prior rounds in the comparison window, requiring at least four prior observations and a non-zero median. Six or more observations available for the historical comparison.
- TaizzDeviation from recent trend
- Latest
- 419,068
- Baseline
- 380,712
- Magnitude
- 4.40
- Basis
- 20 obs, adequate
The latest change exceeds 3.0 times the median absolute change of the prior rounds in the comparison window, requiring at least four prior observations and a non-zero median. Six or more observations available for the historical comparison.
- AdenSustained multi-round increase
- Latest
- 303,053
- Baseline
- 300,843
- Magnitude
- 4.08
- Basis
- 21 obs, adequate
Three or more consecutive rounds of positive change, with cumulative growth of at least +25 per cent. Six or more observations available for the historical comparison.
- AmranSudden surge
- Latest
- 252,246
- Baseline
- 157,812
- Magnitude
- 0.60
- Basis
- 11 obs, adequate
Latest round-to-round change is at or above +30 per cent and the absolute increase is at least 1,000 individuals. Six or more observations available for the historical comparison.
- AmranDeviation from recent trend
- Latest
- 252,246
- Baseline
- 157,812
- Magnitude
- 17.78
- Basis
- 11 obs, adequate
The latest change exceeds 3.0 times the median absolute change of the prior rounds in the comparison window, requiring at least four prior observations and a non-zero median. Six or more observations available for the historical comparison.
- Amanat Al AsimahDeviation from recent trend
- Latest
- 243,738
- Baseline
- 215,346
- Magnitude
- 3.30
- Basis
- 11 obs, adequate
The latest change exceeds 3.0 times the median absolute change of the prior rounds in the comparison window, requiring at least four prior observations and a non-zero median. Six or more observations available for the historical comparison.
- IbbSustained multi-round increase
- Latest
- 216,114
- Baseline
- 190,392
- Magnitude
- 0.47
- Basis
- 14 obs, adequate
Three or more consecutive rounds of positive change, with cumulative growth of at least +25 per cent. Six or more observations available for the historical comparison.
- IbbDeviation from recent trend
- Latest
- 216,114
- Baseline
- 190,392
- Magnitude
- 11.08
- Basis
- 14 obs, adequate
The latest change exceeds 3.0 times the median absolute change of the prior rounds in the comparison window, requiring at least four prior observations and a non-zero median. Six or more observations available for the historical comparison.
- DhamarSudden surge
- Latest
- 186,774
- Baseline
- 121,416
- Magnitude
- 0.54
- Basis
- 11 obs, adequate
Latest round-to-round change is at or above +30 per cent and the absolute increase is at least 1,000 individuals. Six or more observations available for the historical comparison.
- DhamarDeviation from recent trend
- Latest
- 186,774
- Baseline
- 121,416
- Magnitude
- 8.30
- Basis
- 11 obs, adequate
The latest change exceeds 3.0 times the median absolute change of the prior rounds in the comparison window, requiring at least four prior observations and a non-zero median. Six or more observations available for the historical comparison.
- Sa'AdaSudden surge
- Latest
- 170,544
- Baseline
- 121,698
- Magnitude
- 0.40
- Basis
- 11 obs, adequate
Latest round-to-round change is at or above +30 per cent and the absolute increase is at least 1,000 individuals. Six or more observations available for the historical comparison.
Methodology and provenance
- Source
- International Organization for Migration (IOM), Displacement Tracking Matrix (DTM). Public API v3.
- Endpoint
- /v3/displacement/admin1
- Geographic level
- Admin 1
- Operation
- Yemen conflict
- Reporting period
- 2015-07-30 to 2025-02-01
- Assessment round
- Round 40
- Retrieved
- 2026-09-04 01:37 UTC
- Calculation
- Transparent statistical rules applied to each area's own trailing series within the operation. No model is fitted and no learned parameters are used.
Known limitations
- An anomaly can be produced by a change in assessment coverage or method rather than by population movement.
- Areas with short histories are flagged as low quality because normal variation cannot be characterised.
- The public API supplies no adjacency graph, so no claim of spatial contiguity is made.
MOSAIC-derived indicator. Not an IOM classification.
Geographic concentrationMOSAIC-derived
Displacement is moderately concentrated across 13 assessed units, with 82.0 per cent in the largest 3.
| Area | Present IDPs | Share |
|---|---|---|
| Marib | 1,792,022 | 58.4% |
| Taizz | 419,068 | 13.7% |
| Aden | 303,053 | 9.9% |
Normalised concentration index: 0.323 on a zero-to-one scale across 13 assessed areas.
Methodology and provenance
- Source
- International Organization for Migration (IOM), Displacement Tracking Matrix (DTM). Public API v3.
- Endpoint
- /v3/displacement/admin1
- Geographic level
- Admin 1
- Operation
- Yemen conflict
- Reporting period
- 01 Feb 2025
- Assessment round
- Round 40
- Retrieved
- 2026-09-04 01:37 UTC
- Calculation
- Concentration is computed over the administrative units reported in the selected round of the selected DTM operation. It uses the Herfindahl-Hirschman Index of unit shares, normalised so that zero is an even distribution across assessed units and one is total concentration in a single unit. Units not assessed in the round are absent from the calculation, so a narrowing of assessment coverage will raise measured concentration without any population movement.
Known limitations
- Concentration rises mechanically when assessment coverage narrows, with no population movement required.
MOSAIC-derived indicator. Not an IOM classification.
Coverage and confidenceMOSAIC-derived
What the observation process supports, stated separately from what the figures say.
- Assessed areas, latest
- 13
- Assessed areas, baseline
- 13
- Rounds in operation
- 22
- Median round interval
- 59 days
- The most recent assessment in this operation is more than a year old. Treat every derived indicator as historical rather than current.
Confidence derivation
The change rests on two comparable consecutive rounds within one operation, with stable assessment coverage and a recent reporting date.
- −25: Latest assessment is more than a year old
Methodology and provenance
- Source
- International Organization for Migration (IOM), Displacement Tracking Matrix (DTM). Public API v3.
- Endpoint
- /v3/displacement/admin1
- Geographic level
- Admin 1
- Operation
- Yemen conflict
- Reporting period
- 2015-07-30 to 2025-02-01
- Assessment round
- Round 40
- Retrieved
- 2026-09-04 01:37 UTC
- Calculation
- MOSAIC confidence describes how well a change is grounded in comparable DTM observations. It begins at 100 and applies fixed deductions for missing baselines, non-consecutive rounds, coverage changes, short unit histories and assessment age. It is a statement about data comparability and recency only. It carries no claim about the cause of a change.
Known limitations
- Confidence describes data comparability and recency only. It carries no claim about the cause of a change.
MOSAIC-derived indicator. Not an IOM classification.
Recorded displacement reason, latest round
Taken directly from the DTM records. This is a source field, not a MOSAIC classification.
| Reason | Present IDPs | Share |
|---|---|---|
| Conflict | 2,950,779 | 96.2% |
| Economic reasons | 99,390 | 3.2% |
| Natural disaster | 16,161 | 0.5% |
Methodology and provenance
- Source
- International Organization for Migration (IOM), Displacement Tracking Matrix (DTM). Public API v3.
- Endpoint
- /v3/displacement/admin1
- Geographic level
- Admin 1
- Operation
- Yemen conflict
- Reporting period
- 01 Feb 2025
- Assessment round
- Round 40
- Retrieved
- 2026-09-04 01:37 UTC
- Calculation
- The displacementReason field on each source row, summed over the latest round of the selected operation.
Known limitations
- Reason is recorded at assessment. It reflects the reason as reported, and may not capture compound or sequential causes.
Generate analyst brief
A deterministic, template-generated brief covering situation snapshot, key changes, trend, concentration, anomalies, analytic questions, information gaps, collection priorities and methodological caveats. No generative model is in the path, so the same data always produces the same brief.