方法論

1. Sources

Everything shown is group-level statistics published by international organisations. This site never handles person-level data.

Full provenance per source (endpoints, content hashes, retrieval times, caveats) is machine-readable in sources.json. Not used: ACLED (licence forbids dashboard republication), IOM DTM (licence not yet confirmed), UNHCR Operational Data Portal and microdata (non-commercial terms).

2. What these numbers are, and are not

• They are what governments and UNHCR operations report. States have incentives to over- and under-count — funding appeals, sovereignty claims, contested legal statuses. A missing figure is not an absence of displaced people; grey is not zero.
• Coverage and definitions vary by country and year; watch for definition changes when comparing across time (e.g. OIP exists only from 2018).
• IDP figures cover conflict and violence only (IDMC); disaster displacement is not in the annual stocks.
• Nowcast and IDU figures are estimates / preliminary, labelled as such, and never mixed into the annual series.
• Mapping requires a polygon: a few reporting entities (Martinique, Gibraltar, "Stateless", "Unknown"…) have no drawable boundary; they are listed in the legend and included in all totals, tables and downloads.
• UNHCR figures exclude Palestine refugees under UNRWA's mandate (about 6 million), counted separately by UNRWA.

3. Pipeline: daily, static, audited

1. Fetch — a scheduled job calls the UNHCR API (throttled: 2 concurrent requests, ≥ 300 ms apart, retries with back-off) and downloads the WPP CSV and the IDMC IDU dump. The latest year with published data is detected automatically (currently 2025).
2. Normalise — every row is keyed by ISO 3166-1 alpha-3 read from UNHCR's coo_iso/coa_iso fields. UNHCR's internal codes (coo/coa) are never used: they collide with real ISO3 codes (UNHCR "AUS" is Austria, "ARE" is Egypt, "MAR" is Martinique). Numeric fields arrive as "-" (not reported), "0" or numbers; they are converted to null / 0 / integer.
3. Validate — 15 invariants must hold before anything is published, including: the three collision cases are keyed correctly; no negative or non-finite values; mapped total + unmappable total = global total for every metric and year; totals do not drift more than 20 % against the previous snapshot; and three golden numbers (Türkiye refugees 2024, Syria IDPs 2016, world refugees 2024) match within 1 %.
4. Promote — each source is promoted independently. If a source fails, its previous snapshot stays online and the site shows a "partial data update delayed" chip; after three consecutive days the maintainer is e-mailed.
5. Publish — the data files are committed to the repository (a permanent audit trail: git log -- public/data/v1/country/SYR.json answers "what did this number say on day X") and deployed as static files. The browser never calls UNHCR.

4. Definitions

難民

1951年条約／1967年議定書、1969年OAU条約、またはUNHCR規程に基づき難民と認定された人々、および補完的・補助的保護や一時的保護を受ける人々。難民に類似した状況にある人々を含む。UNRWAの任務下にあるパレスチナ難民は含まない。

• 年末（12月31日）時点のストック。
• UNRWA登録のパレスチナ難民（約600万人）は含まない。

庇護希望者

国際保護を申請し、難民認定の判断がまだ出ていない人々（係属中の案件）。

• 年末時点の係属案件。人数ベース。

国内避難民（IDP）

紛争や暴力によって自国内で避難を強いられた人々（IDMCが集計し、UNHCR経由で公表）。自国の下に計上（出身国＝庇護国）。

• 出典：IDMC（UNHCR経由）。災害による避難は含まない。
• 両ビューで同一（国内避難に受入国はない）。

無国籍者

いずれの国の法律によっても国民と認められない人々。国籍未確定の人々を含む。

• 居住国別のみ報告。多くの国は未報告。

その他の支援対象者

他のいずれの区分にも直接は該当しないが、UNHCRが保護・支援を提供している人々。

帰還難民

その暦年中に自発的または組織的に出身国へ帰還した元難民。

• 年中のフロー。ストックではない。

帰還国内避難民

その暦年中に元の居住地域へ帰還した元国内避難民。

• 年中のフロー。ストックではない。

国際保護を必要とするその他の人々

出身国の外にいて国際保護を必要とする可能性が高いが、地位が未確定の人々（2018年から使用。主に国外のベネズエラ人）。

• 2018年から報告。大半は国外に逃れたベネズエラ人。

受入コミュニティ

UNHCRの事業の恩恵を受ける受入コミュニティの構成員（報告は一部の事業のみ）。

• 避難民ではないため合計から除外。

支援対象者合計

難民、庇護希望者、国内避難民、無国籍者、その他の支援対象者、国際保護を必要とするその他の人々の合計（受入コミュニティと帰還者は含まない）。

• クライアント側で構成指標から合算。null の構成要素は、少なくとも1つの構成要素が報告されている場合にのみ 0 として扱う。

All stock figures are year-end (31 December). "Returned" figures are flows during the year.

5. Null is not zero

UNHCR distinguishes not reported ("-") from reported zero. We keep that distinction everywhere: on the map (grey vs the lightest blue), in charts (a gap in the line vs a point at 0), in CSV (empty field vs 0) and in JSON (null vs 0). A country in grey may host many displaced people whose figures simply were not reported that year.

6. Two views: where they are, where they fled from

Every figure has two geographies. Country of asylum ("where they are now") counts people where they currently live. Country of origin ("where they fled from") counts the same people by the country they left. Internally displaced persons are counted in their own country in both views. The "Flows" tab and the flows/ files give the bilateral matrix.

7. Per 1,000 residents

Rate = persons ÷ UN WPP mid-year total population × 1,000. Two caveats: the numerator is a 31 December stock while the denominator is 1 July; and WPP values after the estimate base year are medium-variant projections. Rates are not shown where population is missing.

8. Colour scales

A single-hue blue ramp (ColorBrewer Blues) is used throughout — no red/orange scales, which would visually frame displaced people as a threat. Seven classes. Default breaks are quantiles computed across the whole year range for the countries shown: while you scrub the timeline, colour means magnitude, not a rank that reshuffles every year — so screenshots from different years are comparable. Zero has its own lightest colour; not-reported is grey.

9. Boundaries and names

Boundaries come from Natural Earth, simplified for display. Country names follow the data source being cited (UNHCR), with a small override table for readability (e.g. "Syrian Arab Rep." → "Syria"); the original name is always shown alongside. Disputed territories, Kosovo and Taiwan are handled explicitly — see Boundaries, names and disputed territories.

10. Freshness and failure

UNHCR publishes annual figures around June and mid-year figures around October/November. The pipeline runs daily but only commits when content changes. Three timestamps are kept apart: data_as_of (what the data covers), retrieved_at (when we fetched it — only advances when content changed) and the dataset snapshot_id (content hash of the whole dataset, currently 21506b7d). The bulk CSVs carry the population source's content-hash prefix in their snapshot column, resolvable via sources.json.

11. The live events layer

The "recent internal displacement events" layer republishes IDMC's preliminary event-level estimates. For dignity and safety: coordinates of conflict events are snapped to a ~25 km grid (never settlement-level); events under 100 people are not drawn as individual points; the popup shows figure, type and date and links to IDMC's own report instead of pasting narrative text. Event definitions differ from the annual IDP stock (which excludes disasters).

12. Citing

Every view has a permanent link that reproduces year, metric, view, filters, selection and map position (links produced by Share/Cite pin the year). The "Cite" button gives APA 7, Chicago (author–date), BibTeX (@dataset with version) and a plain "cite this page" string; the publication year is the data year, not the year you clicked, and the snapshot id is included for exact recovery. Please cite the upstream source as well as this site.

Questions or corrections: see このサイトについて.