1001 Smart Cities
🇰🇷 Busan

Busan Urban Flood Warning System (Busan Safety ON)

🤖 AI-generated summary · ◆ 10 sourced claims · 🔎 Last verified

This overview was generated with AI from the public sources listed below and checked against them before publication. It has not had a complete human fact-check — treat it as a starting point and follow the sources.

10 sourced claims on this page, none individually verified yet — turn on “Sources in the text” to see each one.

How this atlas is made · What “last verified” means · What “source-checked” means · The full record behind this page

Three drivers drowned in a flooded underpass in 2020. Four years on, the city could tell you an underpass was filling, but 41 of its 57 underpasses were still exempt from the rule requiring an automatic entry barrier.

Outcome🔄 Ongoing
Evidence🏛️ Officialgrades the sourcing — this entry states no impact figure
what does this mean?The strongest source is the operator's or the city's own reporting — an official report, dataset or press release. It grades who did the looking — not how well the project went. All four grades →
Run byBusan Metropolitan City — Citizen Safety Office (Natural Disaster Division)
Scale🏙️ City-wide

Part of 1001 Smart Cities — 1,167 documented projects · 🏙️ 9 more in Busan · 📡 Sensors & IoT guide · 🌱 Environment projects

After the July 2020 Choryang underpass flood killed three drivers, Busan mapped inundation risk across 201 neighbourhoods and in May 2023 put the result online at safecity.busan.go.kr. The portal merges flood-detection sensors, rain gauges, river-level gauges and tide readings with national rainfall forecasts, grading each area safe, caution, alert or danger alongside CCTV, road closures and evacuation routes. The city warned at launch that readings could be inaccurate: too few instruments, an algorithm untested in real storms. Full operation followed in May 2024; a 2026 rebuild widened the portal into Busan Safety ON, covering six hazard fields, with sensors planned on the highest-risk steep slopes to alarm the district office automatically.

Live 📅 since 2023

🎓 Lesson

Busan can tell you an underpass is filling before it can be closed: four years after Choryang, 41 of the city's 57 underpasses still fell outside the rule that makes an automatic entry barrier compulsory, and nationwide only 164 of 402 underpasses had one fitted. Warning outran actuation.

🌱 EnvironmentSensors & IoTFlood resilienceSafety & securityDigital government

Sources

↗ Asiae — Busan pushes an integrated urban flood management system (13 Apr 2023)Carries the city's own caveat that early flood-risk readings may be inaccurate because observation equipment and data are insufficient and the algorithm is unvalidated in real conditions; names the Citizen Safety Office as owner.
↗ Busan Ilbo — integrated urban flood information goes live (22 May 2023)Supports the May 2023 service launch at safecity.busan.go.kr, the trial period running to April 2024 with full operation from May 2024, the Natural Disaster Division as operator, and the real-time data set including river water level, tide level and rainfall.
↗ Busan Metropolitan City — first urban flood hazard maps produced (13 May 2021)Official press release: citywide inundation-cause analysis completed December 2020, maps covering 201 eup, myeon and dong across all 16 districts and counties. This is the map layer the 2023 system was built on.
↗ Segye Ilbo — Busan: from flood maps to shelters at a glance (3 Feb 2026)Published 3 February 2026Supports the February 2026 rebuild into the six-field Busan Safety ON portal (urban flooding, earthquake, nuclear safety, sinkhole and landslide, heat and cold waves, shelters), trial February to April 2026, full operation from May 2026.
↗ Seoul Economic Daily — Busan enters summer storm response posture (13 May 2026)Current status: Busan Safety ON in full operation, integrating river water-level and CCTV data; sensors on high-risk Grade-C steep slopes that alarm local authorities automatically when thresholds are crossed; coastal wave overtopping named as one of six Busan-specific storm risks.
Show 4 more sourcesShow fewer
↗ Busan Safety ON — the live public portalThe operating service itself; confirms the system is live under the city's own domain as of July 2026.
↗ Busan Ilbo — four years after Choryang, 41 underpasses remain flood blind spots (18 Jul 2024)Independent counterweight behind the lesson: 41 of Busan's 57 underpasses (72%) fall outside the mandatory automatic entry-barrier requirement, four years after the 2020 Choryang deaths; barriers are designed to trigger above 15 cm of water.
↗ Busan Metropolitan City — keeping Marine City safe from wave overtoppingPublished 3 February 2025Context for the coastal side: Busan's answer to Marine City overtopping is a 500 m submerged breakwater 150 m offshore, completion targeted end-2027. Cited to show it is passive hard engineering with no sensing or automated-closure layer, so it is not part of this entry.
↗ Busan Metropolitan City — Busan pushes the country’s first integrated urban flood management system (13 Apr 2023)City press release. Names the four risk stages (safe, caution, alert, danger), the sensor mix behind them (flood-detection sensors, rain gauges, river-level gauges) combined with the Korea Meteorological Administration's rainfall forecast, and the 2019-20 study that produced the citywide inundation maps. Replaces the Smart City Korea copy of the same release, which now returns 404.

📅 How old is the evidence?

Two clocks, kept apart: when this entry’s sources were published, and what has happened to its record in the atlas. Documented span: since 2023. 8 of 9 sources carry a publication date, from 13 May 2021 to 13 May 2026.

When the sources were published

  1. Busan Metropolitan City · city governmentBusan Metropolitan City — first urban flood hazard maps produced (13 May 2021)
  2. Asia Economy (아시아경제) · pressAsiae — Busan pushes an integrated urban flood management system (13 Apr 2023)
  3. Busan Metropolitan City · city governmentBusan Metropolitan City — Busan pushes the country’s first integrated urban flood management system (13 Apr 2023)
  4. Busan Ilbo (부산일보) · pressBusan Ilbo — integrated urban flood information goes live (22 May 2023)
  5. Busan Ilbo (부산일보) · pressBusan Ilbo — four years after Choryang, 41 underpasses remain flood blind spots (18 Jul 2024)
  6. Busan Metropolitan City · city governmentBusan Metropolitan City — keeping Marine City safe from wave overtopping
  7. Segye Ilbo · pressSegye Ilbo — Busan: from flood maps to shelters at a glance (3 Feb 2026)
  8. Seoul Economic Daily · pressSeoul Economic Daily — Busan enters summer storm response posture (13 May 2026)

Every source, with links ↑

What happened to this record

  1. Entered the record
  2. Sources last read

Every revision, permanent →

Show your work What this page rests on and what it can’t tell you · all 10 claims with their sources · the forensic record

Evidence Passport · public beta 10 addressable claims, 9 source dossiers, one permanent baseline. The passport is unreviewed — an AI-assisted structural migration, not a human or expert endorsement. Every revision keeps a permanent copy under revision history.

Inspect the claims, one by one — verbatim text, sources and caveats for all 10

The text below is copied verbatim from the published record. Each claim names the source dossiers that carry it; caveats stay attached to the claim they qualify.

Claim 1 clm-5dc35d61dbac5f19 quantitative
After the July 2020 Choryang underpass flood killed three drivers
Published field
snippet · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
Local daily recalling the accident: three people trapped in their vehicles died in the Choryang No. 1 underpass during the record rainfall of 23 July 2020.
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. Busan Ilbo — four years after Choryang, 41 underpasses remain flood blind spots (18 Jul 2024)
Claim 2 clm-2a7fda1d18b22ba8 quantitative
Busan mapped inundation risk across 201 neighbourhoods
Published field
snippet · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
City press release: the flood hazard information map was produced for and distributed to 201 eup, myeon and dong across the 16 districts and counties, after a citywide analysis of inland flooding causes completed in December 2020.
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. Busan Metropolitan City — first urban flood hazard maps produced (13 May 2021)
Claim 3 clm-2c3e1431dc03b01c quantitative
in May 2023 put the result online at safecity.busan.go.kr
Published field
snippet · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
Local daily on the launch: from that month the city ran the country's first site giving real-time urban flooding information, at safecity.busan.go.kr.
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. Busan Ilbo — integrated urban flood information goes live (22 May 2023)
Claim 4 clm-6a1f6b0e02c2a831 descriptive
The portal merges flood-detection sensors, rain gauges, river-level gauges and tide readings with national rainfall forecasts, grading each area safe, caution, alert or danger
Published field
snippet · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
City press release: real-time data from flood-detection sensors, rain gauges and river-level gauges is combined with the Korea Meteorological Administration's rainfall forecast to produce four grades of flood risk — safe, caution, alert, danger.
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. Busan Metropolitan City — Busan pushes the country’s first integrated urban flood management system (13 Apr 2023)
  2. Asiae — Busan pushes an integrated urban flood management system (13 Apr 2023)
Claim 5 clm-0af4a889399e388a descriptive
The city warned at launch that readings could be inaccurate: too few instruments, an algorithm untested in real storms
Published field
snippet · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
The city's own caveat: in the early phase the flood-risk information generated may be somewhat inaccurate because of a shortage of observation equipment and collected data and because the algorithm has not been validated in real conditions.
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. Asiae — Busan pushes an integrated urban flood management system (13 Apr 2023)
  2. Busan Metropolitan City — Busan pushes the country’s first integrated urban flood management system (13 Apr 2023)
Claim 6 clm-a51cb0413f7757be quantitative
Full operation followed in May 2024
Published field
snippet · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
Local daily: trial operation ran from that month until April of the following year, with full operation planned from May 2024.
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. Busan Ilbo — integrated urban flood information goes live (22 May 2023)
Claim 7 clm-a653cfef3f35382b quantitative
a 2026 rebuild widened the portal into Busan Safety ON, covering six hazard fields
Published field
snippet · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
National daily: the integrated site Busan Safety ON is organised in six fields — urban flooding, earthquake and seismic retrofitting, nuclear safety, sinkholes and landslides, heat and cold waves, and shelters — and ran in trial operation until the end of April.
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. Segye Ilbo — Busan: from flood maps to shelters at a glance (3 Feb 2026)
Claim 8 clm-a1e71896ce7e4160 descriptive
with sensors planned on the highest-risk steep slopes to alarm the district office automatically
Published field
snippet · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
Economic daily quoting a city official: sensors are to be installed on grade C, highest-risk steep slopes and will send an automatic warning alarm to the local authority when a risk value is reached.
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. Seoul Economic Daily — Busan enters summer storm response posture (13 May 2026)
Claim 9 clm-28d77448ce0108a6 quantitative
41 of the city's 57 underpasses still fell outside the rule that makes an automatic entry barrier compulsory
Published field
lesson · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
Local daily working from a National Assembly member's figures: of Busan's 57 underpasses only 16 are subject to the mandatory entry-barrier requirement, leaving 41 outside it. The barrier automatically blocks vehicles once water inside the underpass reaches 15 cm.
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. Busan Ilbo — four years after Choryang, 41 underpasses remain flood blind spots (18 Jul 2024)
Claim 10 clm-80ceb3618f723343 quantitative
nationwide only 164 of 402 underpasses had one fitted
Published field
lesson · verbatim
Mapping
mapped · no interpretation or interpolation added by this passport
What the mapping says
Same report: of 402 underpasses nationwide, only 164 had the entry-barrier facility installed.
Caveat
No claim-specific caveat recorded

Sources carrying this claim

  1. Busan Ilbo — four years after Choryang, 41 underpasses remain flood blind spots (18 Jul 2024)
Forensic record — source dossiers, gaps, hashes and the exact revision this page renders

This layer records what is known about each source, what is still missing, and the exact snapshot this page is rendering. A missing date, archive or hash stays visible as missing.

unreviewed Revision 2026-08-26-p1-quality-uplift effective 2026-08-26 · created 2026-08-26

Awaiting operator and domain-expert review; publication of this revision implies neither.

Erratum on this revision's envelope. The snapshot, its hash and its permanent link are untouched.

  • createdAt previously read 2026-08-26T21:00:00Z. The batching script that produced this revision advanced createdAt into the future to satisfy the strictly-increasing order the validator requires per entity. The value never recorded a real event; the corrected value is the moment the revision provably existed in the repository. Corrected to 2026-08-26T14:41:50Z on 2026-08-27; evidence: first appears in commit 9d65ace88e, committed 2026-08-26T14:41:50Z.
sha256:c0b43288580bf702bc5709d0111324f3bff36454f47f83853ebf42d9309dd773
Revision history → Permanent version link → Machine-readable record → Evidence Constitution →
10
of 10 claims mapped
9
source dossiers
8
publication dates recorded
0
archives linked
0
exact locators
0
content captures hashed

Governance facts carried by the record

Operator
Busan Metropolitan City — Citizen Safety Office (Natural Disaster Division)
Actor types
city-government
Funding model
public
Funding description
Not recorded
Cost
Not recorded
Ownership
Not recorded
Decision rights
Not recorded
Exit conditions
Not recorded

9 source dossiers

Asiae — Busan pushes an integrated urban flood management system (13 Apr 2023) asiae.co.kr · 2 linked claims

Open original source ↗

Stable source ID
src-dd42daf8c541b050
Publisher
Name not classified · asiae.co.kr
Type / language
web-page · language not classified
Published
2023-04-13
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-08-26
Dossier created
2026-08-26
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
Locator
Open the recorded source note

Carries the city's own caveat that early flood-risk readings may be inaccurate because observation equipment and data are insufficient and the algorithm is unvalidated in real conditions; names the Citizen Safety Office as owner.

Descriptive only — not page/paragraph exact
Claims linked
Busan Ilbo — integrated urban flood information goes live (22 May 2023) busan.com · 2 linked claims

Open original source ↗

Stable source ID
src-bf55856f5727e463
Publisher
Name not classified · busan.com
Type / language
web-page · language not classified
Published
2023-05-22
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-08-26
Dossier created
2026-08-26
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
Locator
Open the recorded source note

Supports the May 2023 service launch at safecity.busan.go.kr, the trial period running to April 2024 with full operation from May 2024, the Natural Disaster Division as operator, and the real-time data set including river water level, tide level and rainfall.

Descriptive only — not page/paragraph exact
Claims linked
Busan Metropolitan City — first urban flood hazard maps produced (13 May 2021) busan.go.kr · 1 linked claim

Open original source ↗

Stable source ID
src-e002955a1867fa94
Publisher
Name not classified · busan.go.kr
Type / language
web-page · language not classified
Published
2021-05-13
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-08-26
Dossier created
2026-08-26
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
Locator
Open the recorded source note

Official press release: citywide inundation-cause analysis completed December 2020, maps covering 201 eup, myeon and dong across all 16 districts and counties. This is the map layer the 2023 system was built on.

Descriptive only — not page/paragraph exact
Claims linked
Segye Ilbo — Busan: from flood maps to shelters at a glance (3 Feb 2026) segye.com · 1 linked claim

Open original source ↗

Stable source ID
src-4023c30d74a571c7
Publisher
Name not classified · segye.com
Type / language
web-page · language not classified
Published
2026-02-03
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-08-26
Dossier created
2026-08-26
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
Locator
Open the recorded source note

Supports the February 2026 rebuild into the six-field Busan Safety ON portal (urban flooding, earthquake, nuclear safety, sinkhole and landslide, heat and cold waves, shelters), trial February to April 2026, full operation from May 2026.

Descriptive only — not page/paragraph exact
Claims linked
Seoul Economic Daily — Busan enters summer storm response posture (13 May 2026) sedaily.com · 1 linked claim

Open original source ↗

Stable source ID
src-e8a2ef6b5f599cd5
Publisher
Name not classified · sedaily.com
Type / language
web-page · language not classified
Published
2026-05-13
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-08-26
Dossier created
2026-08-26
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
Locator
Open the recorded source note

Current status: Busan Safety ON in full operation, integrating river water-level and CCTV data; sensors on high-risk Grade-C steep slopes that alarm local authorities automatically when thresholds are crossed; coastal wave overtopping named as one of six Busan-specific storm risks.

Descriptive only — not page/paragraph exact
Claims linked
Busan Safety ON — the live public portal safecity.busan.go.kr · background

Open original source ↗

Stable source ID
src-d4942481bc5ecf8d
Publisher
Name not classified · safecity.busan.go.kr
Type / language
web-page · language not classified
Published
Not recorded
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-08-26
Dossier created
2026-08-26
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
Locator
Open the recorded source note

The operating service itself; confirms the system is live under the city's own domain as of July 2026.

Descriptive only — not page/paragraph exact
Claims linked
Background source; no baseline claim points here
Busan Ilbo — four years after Choryang, 41 underpasses remain flood blind spots (18 Jul 2024) busan.com · 3 linked claims

Open original source ↗

Stable source ID
src-6e16c8778b9fc6f8
Publisher
Name not classified · busan.com
Type / language
web-page · language not classified
Published
2024-07-18
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-08-26
Dossier created
2026-08-26
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
Locator
Open the recorded source note

Independent counterweight behind the lesson: 41 of Busan's 57 underpasses (72%) fall outside the mandatory automatic entry-barrier requirement, four years after the 2020 Choryang deaths; barriers are designed to trigger above 15 cm of water.

Descriptive only — not page/paragraph exact
Claims linked
Busan Metropolitan City — keeping Marine City safe from wave overtopping busan.go.kr · background

Open original source ↗

Stable source ID
src-40077e966e102acc
Publisher
Name not classified · busan.go.kr
Type / language
web-page · language not classified
Published
2025-02-03
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-08-26
Dossier created
2026-08-26
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
Locator
Open the recorded source note

Context for the coastal side: Busan's answer to Marine City overtopping is a 500 m submerged breakwater 150 m offshore, completion targeted end-2027. Cited to show it is passive hard engineering with no sensing or automated-closure layer, so it is not part of this entry.

Descriptive only — not page/paragraph exact
Claims linked
Background source; no baseline claim points here
Busan Metropolitan City — Busan pushes the country’s first integrated urban flood management system (13 Apr 2023) busan.go.kr · 2 linked claims

Open original source ↗

Stable source ID
src-0796b5f0903866db
Publisher
Name not classified · busan.go.kr
Type / language
web-page · language not classified
Published
2023-04-13
Updated
Not recorded
Source last checked
No source-level check date
Record last verified
2026-08-26
Dossier created
2026-08-26
Retrieved copy
No local capture recorded
Archive
No archived copy linked
Content hash
No captured content hash
Locator
Open the recorded source note

City press release. Names the four risk stages (safe, caution, alert, danger), the sensor mix behind them (flood-detection sensors, rain gauges, river-level gauges) combined with the Korea Meteorological Administration's rainfall forecast, and the 2019-20 study that produced the citywide inundation maps. Replaces the Smart City Korea copy of the same release, which now returns 404.

Descriptive only — not page/paragraph exact
Claims linked
Known limits of this passport
  • Publisher names and source languages have not yet been classified; domains are recorded without guessing.
  • Existing source notes are descriptive locators, not page- or paragraph-exact citations.
  • A missing archive, publication date or content hash is shown as null rather than inferred.
  • The project-level evidence grade ranks the strongest source in the entry; it is not a truth score for every claim.

Continue exploring

Compare this project

🇯🇵 Tsunami-Alert Automatic Tide Gate Closure · Osaka Warning versus actuation: an alert closes Osaka's tide gates by itself; Busan's portal warns, but 41 of 57 underpasses have no barrier. 🇮🇳 Bengaluru Urban Flood Early-Warning Network · Bengaluru Both name their own limit: Bengaluru's drains hold about 80 mm; Busan warned at launch that its instruments were too few to trust. 🇰🇷 Busan's 16 District CCTV Integrated Control Centres · Busan Busan's flood portal draws on these district CCTV feeds to show closed roads and rising water alongside its sensor readings.

When the river rises: what is the reading allowed to do?

Four flood systems, four answers to the question that organises much of this atlas — whether a measurement triggers anything. The ladder runs from a reading that acts entirely by itself down to a network that watches everything and decides nothing.

ProjectSinceStatusOutcomeEvidenceRun byCostWhat the reading may do
Tsunami-Alert Automatic Tide Gate ClosureOsaka, 🇯🇵 2018 Live Ongoing Official Regional government not public The reading acts by itself: the tide gates close automatically on the national alert, with no human in the loop.
Bangkok Flood Control Centre: Drainage Telemetry & Street-Level ForecastingBangkok, 🇹🇭 2021 Live Ongoing Official City government, Utility or public operator not public Staff decide with the data: radars and level sensors feed a control centre staffed around the clock, and crews operate the pumps.
Busan Urban Flood Warning System (Busan Safety ON)Busan, 🇰🇷 2023 Live Ongoing Official City government not public Warning only: the portal shows risk and alerts residents, and the city itself cautioned at launch that the readings could be wrong.
SIATA Early Warning NetworkMedellín, 🇨🇴 2010 Live Ongoing Media Research institution not public A research-run regional network that watches everything — including, once, a fatal flash flood in real time that no agency acted on.

Explore the wider context

📟 A Reading Is Not a Decision📖 Flood early-warning system📖 Automated speed enforcement (speed cameras)📖 Integrated command and control centre (ICCC)
📎 Cite this project

1001 Smart Cities (2026). “Busan Urban Flood Warning System (Busan Safety ON)” — Busan, South Korea. The Smart City Atlas. https://1001smartcities.org/projects/busan-urban-flood-warning-system/ (last verified 2026-08-26). Data: CC BY 4.0.

The underlying data is free to reuse with attribution — see the open data page.

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