Istanbul's Digital Archives Are Full of the Same Image Twice — Officials and Experts Want That Fixed

Istanbul's municipal digital repositories — spanning earthquake-risk surveys, heritage documentation, and tourism promotion — contain tens of thousands of duplicate image files, a problem that experts say is inflating storage costs, muddying urban planning decisions, and compromising the integrity of records that matter most after a disaster. The issue has surfaced publicly in recent weeks as the Istanbul Metropolitan Municipality's information technologies directorate began an internal audit of its archival systems ahead of a broader digitisation push scheduled for the second half of 2026.

The timing is not accidental. Since the February 2023 Kahramanmaraş earthquakes, Istanbul has been under pressure to complete structural surveys of at-risk buildings across districts including Fatih, Zeytinburnu, and Avcılar — all of which sit on soft alluvial ground close to the main Marmara fault line. Those surveys generate thousands of photographs. When field teams submit the same inspection image under different file names, or when legacy systems automatically re-ingest files during server migrations, the duplicates accumulate. Database administrators at the municipality's Saraçhane headquarters have acknowledged the scale of the problem is larger than initially anticipated, though no official figure has been released publicly.

What the Experts Are Saying

Specialists in digital preservation are watching Istanbul closely. SALT Research, the archive and library operated by Garanti BBVA on İstiklal Caddesi, has dealt with its own image deduplication challenges in managing roughly 1.5 million digitised items from Ottoman and early Republican-era collections. Staff there have spoken publicly at conferences about how automated hashing tools — software that generates a unique fingerprint for each image file — can reduce duplicate rates by more than 60 percent in large municipal datasets, based on comparable projects in European city archives. SALT has not commented specifically on the municipality's current audit.

The Istanbul branch of TMMOB, the Union of Chambers of Turkish Engineers and Architects, has been pressing for cleaner data pipelines in the post-earthquake building inventory since 2023. Engineers working on the urban transformation programme in districts like Bağcılar have noted in professional forums that when duplicate field photographs enter a shared database, assessors can inadvertently review the same structural damage twice, skewing risk scores. The practical consequence: some buildings may be flagged as higher priority for reinforcement than the physical evidence warrants, while others may be deprioritised.

At Istanbul Technical University's Faculty of Architecture, researchers running a separate documentation project on the historic wooden yalıs along the Bosphorus have been open about their own workflows. A project summary published by the faculty in late 2025 noted that deduplication was built into their image management protocol from the start, precisely because earlier pilot surveys in Arnavutköy produced a dataset where roughly one in five photographs was a near-duplicate of another.

What Comes Next for the Municipality

The Metropolitan Municipality has indicated it intends to procure deduplication and asset management software through a public tender process, with a call expected before the end of the third quarter of 2026. Opposition CHP councillors on the city assembly's technology committee have pushed for the tender specifications to be made public before submission, arguing that transparency in procurement is especially important given the lira's continued weakness — any software contract priced in euros or dollars carries a meaningful currency risk for the municipal budget.

For residents and heritage advocates, the practical stakes are clear. The Fatih district alone contains more than 600 structures listed in Turkey's cultural property register. Accurate, deduplicated photographic records are the baseline for any insurance claim, restoration grant, or emergency response plan. If the audit confirms that significant portions of those records contain redundant or mislabelled files, remediation will take months.

Experts advising the process say the municipality should also establish a retention policy — deciding not just how to remove duplicates, but how long original survey images must be kept and in what format. Without that, the same problem will re-emerge within three to five years as new survey cycles begin. The audit report is expected to be presented to the city assembly's relevant committee before the end of July 2026.