Guide for future sub-district (nahiya) mapping — how the folded populations should be split

Several 2024-census units have no boundary of their own in OSM, so their population is currently folded into the district polygon that contains them (each such polygon carries a note:population explaining the composition). If a future mapper draws these missing sub-district boundaries, this guide shows exactly which population moves where, so the totals stay consistent and the parent polygon can be reduced accordingly.

How to use this: when you create a new nahiya polygon, tag it with the figure shown, then reduce its parent district’s population by the same amount (or, if you split the parent completely, retag each piece). Every block below sums to the parent’s current tag, so the arithmetic stays balanced. All figures are from the 2024 Iraq Census; set population:date=2024 and source:population=2024 Iraq Census on any new polygon.

Sub-units marked (markaz) are the district-centre portion that would remain on the existing district polygon after the others are carved out.

Anbar

Al-Ramadi District — relation 11059955, currently 716,314

Al-Falluja District — relation 11059954, currently 710,773

Al-Qa’im District — relation 11059980, currently 185,229

Diyala

Al-Khalis District — relation 11063406, currently 431,184

Balad Ruz District — relation 11063398, currently 166,845

Karbala

Karbala District — relation 11058046, currently 1,476,842

Wasit

Al-Suwaira District — relation 11052280, currently 292,092

Al-Hai District — relation 11052272, currently 197,969

Al-Nu’maniya District — relation 11052275, currently 196,006

Maysan

Amarah District — relation 11045978, currently 759,526

Dhi Qar

Al-Nasiriyah District — relation 11044703, currently 845,276

Souq al-Shuyukh District — relation 11044692, currently 373,378

Al-Rifa’i District — relation 11044709, currently 308,533

Basra

Al-Basrah District — relation 11042188, currently 1,531,202

Al-Zubair District — relation 11042178, currently 682,482

Al-Qurnah District — relation 11042193, currently 345,827

Al-Midaina District — relation 11042180, currently 309,525

Muthanna

Al-Samawa District — relation 11042617, currently 443,656

Al-Rumaitha District — relation 11042619, currently 300,238

Qadisiyah

Al-Diwaniyah District — relation 11048766, currently 704,743

Al-Shamiya District — relation 11048776, currently 292,108

Al-Hamza District — relation 11048771, currently 266,560

Afak District — relation 11048764, currently 213,899

Baghdad

Al-Kadhimiya District — relation 2964709, currently 1,085,792

Al-Istiqlal District — relation 11083458, currently 323,517

Babil

Al-Hamzah Al-Gharbi District — relation 11053204, currently 303,679

Al-Hashimiyah District — relation 11053207, currently 303,242

Erbil

Erbil District — relation 3829919, currently 1,329,246

Soran District — relation 3829924, currently 198,805

Note: the disputed districts are a separate case

Three districts — Kifri, Khanaqin and Al-Shikhan/Shaykhan — are not folded units. Each is a single whole-district polygon whose population is the sum of the shares the census reported under two different governorates, because the OSM polygon spans the entire district. These should not be split by governorate; they are documented in their own note:population and in earlier diary entries.

Ukasz,

It is probable that the subnational polygons are not all mapped at sub-district level and I did no attempt to change those. I added enough detail to this thread so that if someone decides to subdivide them further it is possible to maintain data integrity.

I will write a comment on all the population notes I added to each polygon so that it is self explanatory.

Correction & final checksum — disputed districts now carry whole-district totals (levels 2, 3, 4, 6 all reconcile)

A correction and a milestone. While running a national-vs-governorate sum check, I found that three districts split by the census between two governorates were only carrying one governorate’s share on OSM, even though each district’s OSM polygon covers the whole district and sits entirely within one governorate. Following the project’s rule — population is tagged to the polygon that geographically contains it — each of these polygons should carry the sum of both census shares.

The three corrected districts

Kifri and Khanaqin polygons lie wholly within Diyala; the Shaykhan polygon lies wholly within Nineveh. So the two governorate tags that hold these polygons were raised to match:

Why the Kurdistan Region tag went down to 6,381,082

The Kurdistan Region (5392650) was holding the official census regional figure, 6,519,129. Because Kifri and Khanaqin (now wholly in Diyala) and Shaykhan (now wholly in Nineveh) sit outside the KRI boundary on OSM, their populations are counted in Diyala/Nineveh, not in the KRI. The KRI tag must reflect what its polygon actually encloses — the sum of its four governorate polygons — so it is now 6,381,082. The 138,047 difference from the census figure is exactly the three disputed shares that fall outside the KRI boundary (Kifri 50,714 + Khanaqin 18,054 + Shaykhan 69,279).

Checksums — every level now reconciles

Level 2 (national) = sum of Level 4 (governorates):

• Sum of all 19 governorate tags: 46,118,793
• National tag (304934): 46,118,793
• Difference: 0

Level 3 (Kurdistan Region) = sum of its four Level 4 governorates:

• Erbil + Sulaymaniyah + Halabja + Duhok: 6,381,082
• KRI tag (5392650): 6,381,082
• Difference: 0

Level 4 (each governorate) = sum of its Level 6 (districts): every one of the 19 reconciles to zero — see the table below.

Full breakdown — Level 2 → 4 → 6

Baghdad

Nineveh

Basra

Erbil

Dhi Qar

Babil

Sulaymaniyah

Kirkuk

Al-Anbar

Diyala

Population reference table — admin levels 2, 4 and 6

A consolidated reference for the 2024 census population now tagged on OSM: the national total (admin_level 2), each governorate (admin_level 4), and every district within it (admin_level 6). Names are in English and local script (Arabic, or Kurdish for the Kurdistan Region governorates); relation numbers link to openstreetmap.org.

Each governorate block ends with a checksum row so the arithmetic is visible at a glance: the sum of the district polygons is shown directly beneath the governorate tag, and the two match.

The Kurdistan Region (admin_level 3) relation is deliberately excluded: its tag is the official census regional figure, which does not equal the simple sum of its four governorate polygons (disputed border districts are counted elsewhere on OSM), so listing it here would break the visual checksum.

Method: population is tagged to the polygon that geographically contains each place. Where a district’s OSM polygon sits in a different governorate than the census table lists it under — الشيخان / Shaykhan (in Nineveh), كفري / Kifri and خانقين / Khanaqin (in Diyala) — it is counted once, in the governorate its polygon occupies. That is why a few governorate totals differ from the published census governorate figures.

admin_level 2 — National

admin_level 4 & 6 — Governorates and their districts

Baghdad

Nineveh

Basra

Erbil

Dhi Qar

Babil

Sulaymaniyah

Kirkuk

Al-Anbar

Al-Najaf

Diyala

Saladin

Karbala

Wasit

Duhok

Al-Qadisiyah

Maysan

Muthanna

Halabja

Update — Babil complete: the last two districts are now tagged

A follow-up to close the loop on the two Babil districts I had left untagged: Al-Hashimiyah District (11053207) and Al-Hamzah Al-Gharbi District (11053204). Both now carry 2024 census population, and the reasoning is worth documenting because it turned out to be the most tangled case in the whole country.

Why these two were hard

The published governorate/district summary I worked from originally gave two figures for this area: الهاشمية / “Al-Hashimiya” qada 359,137 and القاسم / “Al-Qasim” qada 247,784 — two separate districts. But OSM does not draw them the same way the census counts them. OSM nests the sub-districts (nawāḥī) like this:

• Al-Hashimiyah District (11053207) contains: القاسم / “Al-Qasim” (11053208), مركز قضاء الهاشمية / “Al-Hashimiyah Central” (11053210), and الطليعة / “Al-Tulayah” (11053209).
• Al-Hamzah Al-Gharbi District (11053204) contains: المدحتية / “Al-Madhatiya” (11053205) and الشوملي / “Al-Shawmali” (11053211).

So OSM’s “Al-Hashimiyah District” polygon is not the same area as the census “Al-Hashimiya qada”: OSM puts القاسم / “Al-Qasim” inside its Hashimiyah polygon, while the census treats القاسم / “Al-Qasim” as a district in its own right. The two schemes cut the same ground differently, which is exactly why I could not resolve these two from the summary alone — I did not want to guess a split.

What resolved it

The Iraqi Central Statistical Organisation (COSIT) published the full, detailed census report — 500+ pages, down to sub-district (nahiya) and even village (qarya / mahalla) level. I retrieved it here:

https://cosit.gov.iq/images/census2024/تقرير%20نتائج%20تعداد%202024.pdf

The nahiya breakdown under الهاشمية / “Al-Hashimiya” qada (report pages 339–342) reads:

• Al-Shawmali — 116,586 (الشوملي)
• Al-Madhatiya / Hamza al-Gharbi — 187,093 (المدحتية / حمزة الغربي)
• Hashimiya district centre — 55,458 (مركز قضاء الهاشمية)
• Sum = 359,137 — matches the Hashimiya qada total exactly.

Al-Qasim is reported separately as its own qada — 247,784 (القاسم).

How the population was assigned (population follows the polygon)

Applying the same rule used throughout this project — each figure goes on the OSM polygon that geographically contains it, not on whichever district the census labels it under — the two OSM district polygons resolve cleanly:

• Al-Hamzah Al-Gharbi District (11053204) = المدحتية / “Al-Madhatiya” 187,093 + الشوملي / “Al-Shawmali” 116,586 = 303,679
• Al-Hashimiyah District (11053207) = القاسم / “Al-Qasim” 247,784 + مركز قضاء الهاشمية / “Hashimiya centre” 55,458 = 303,242

The two OSM district polygons together hold 606,921, which equals the census الهاشمية / “Al-Hashimiya” qada (359,137) + القاسم / “Al-Qasim” qada (247,784). The checksum closes exactly.

One caveat for anyone cross-referencing

Because OSM includes القاسم / “Al-Qasim” inside its Al-Hashimiyah District polygon, the OSM polygon totals do not match the census’s published qada figures, and they are not meant to:

• OSM Al-Hashimiyah District = 303,242, not the census Hashimiya qada 359,137.
• OSM Al-Hamzah Al-Gharbi District = 303,679, which has no single matching row in the census summary at all.

Both numbers are correct for the area each polygon actually encloses. This is the same principle applied to the disputed districts earlier in the project (الشيخان / “Shaykhan”, كفري / “Kifri”): the tag reflects what is inside the polygon, and the composition is spelled out so the figures can be traced back to the census.

Still open (a small one)

At sub-district level, the census reports the مركز قضاء الهاشمية / “Hashimiya district centre” as a single figure of 55,458, but OSM splits that same central area into two nahiya polygons — مركز قضاء الهاشمية / “Al-Hashimiyah Central” (11053210) and الطليعة / “Al-Tulayah” (11053209). The census does not break the 55,458 between them (الطليعة / “Al-Tulayah” does not appear as a separate nahiya in the report), so I have not split it. If a finer source appears, those two sub-district polygons can be populated; the district-level figures above are unaffected and remain exact.

With this, all admin_level 6 district polygons across Iraq now carry 2024 census population — the mapping is complete.