Decoupling and Identification of Urbanization-Induced Signals in Precipitation Patterns in Central Türkiye

Abstract

While the relationship between large-scale deforestation and regional hydro-climatic regimes is widely acknowledged, identifying the specific impacts of rapid urbanization on local precipitation patterns remains a formidable challenge. This difficulty arises because the high-amplitude variability (background climatic noise) driven by large-scale synoptic systems typically masks the low-amplitude, micro-climatic signatures of urban expansion. This study aims to decouple and identify anthropogenic land-use signatures within daily precipitation records in Central Türkiye. We examined daily rainfall and harmonized nighttime light-derived urbanization metrics for four geographically proximate provinces—Ankara, Eskişehir, Kütahya, and Afyonkarahisar—from 2000 to 2020. Despite strong regional synchronization, distinct urbanization trajectories were identified: Ankara peaked around 2005–2006, while neighboring cities accelerated during 2013–2015 and 2019. By employing a multi-phase signal processing approach, we established a “common regional mode” as a shared environmental baseline to extract residual local anomalies for each city. The analysis reveals a statistically discernible correlation between periods of intense urban expansion and local precipitation deviations, distinguishing Ankara’s early onset of anomalies from later shifts in surrounding provinces. These findings demonstrate that urbanization fingerprints can be isolated even amidst dominant regional climate trends. 

Keywords

• Urbanization
• Precipitation Patterns
• Climate Change
• Signal Decoupling
• Regional Modes

Thanks

Yazar, Ankara, Eskişehir, Kütahya ve Afyonkarahisar illerine ait uzun süreli ve yüksek çözünürlükte yağış verisini sağladığı için Türkiye Meteoroloji Genel Müdürlüğü'ne teşekkür eder.

İç Anadolu’daki Yağış Örüntülerinde Kentleşme Kaynaklı Sinyallerin Ayrıştırılması ve Analizi

Abstract

Büyük ölçekli ormansızlaşma ile hidro-iklim rejimi arasındaki ilişki bilinmesine rağmen, hızlı kentleşme süreçlerinin yerel yağış örüntüleri üzerindeki etkileri yerel ölçekte zorlayıcı bir çalışma alanı olmuştur. Zira, büyük ölçekli sinoptik hava olaylarının yarattığı yüksek genlikli değişkenlik (arka plan gürültüsü), yerel kentleşmenin yağış örüntüleri üzerindeki düşük genlikli etkilerini genellikle maskelemektedir. Bu çalışma, İç Anadolu’daki günlük yağış kayıtlarında yer alan antropojenik arazi kullanımı değişim imzasını ayrıştırmayı ve tanımlamayı amaçlamaktadır. 2000-2020 dönemini kapsayan çalışmada; birbirine coğrafi olarak yakın dört ilin (Ankara, Eskişehir, Kütahya ve Afyonkarahisar) günlük yağış veri setleri setleri ve uydu tabanlı gece ışıkları verilerinden elde edilen kentleşme metrikleri incelenmiştir. Bu bölgeler güçlü bir zamansal senkronizasyon sergilese de farklı kentleşme yörüngeleri gözlemlenmiştir: Ankara 2005-2006 civarında önemli bir büyüme atağı yaşarken, komşu şehirler 2013-2015 ve 2019 yıllarında hızlanmıştır. Çok aşamalı bir sinyal işleme yaklaşımıyla, yerel anomalileri belirlemek amacıyla ortak bir çevresel temel çizgiyi temsil eden bir “ortak bölgesel mod” oluşturulmuştur. Analizler, yoğun kentsel büyüme dönemleri ile yerel yağış trendlerindeki sapmalar arasında istatistiksel olarak belirgin bir korelasyon olduğunu ortaya koymaktadır. Bu bulgular, baskın bölgesel iklim trendleri altında bile kentleşme "parmak izinin" izole edilebileceğine işaret etmektedir. 

Keywords

• Kentleşme
• Yağış Örüntüleri
• İklim Değişimi
• Sinyal Ayrıştırma
• Bölgesel Mod

Thanks

The author thanks the Turkish State Meteorological Service for kindly providing long and high-resolution precipitation data of Ankara, Eskişehir, Kütahya, and Afyonkarahisar.

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