Türkiye'nin Doğu Karadeniz Havzası'ndaki Uzun Vadeli Yağış Değişimlerinin Çift Yöntemli Değerlendirmesi

Abstract

Bu çalışmada, 1994-2024 dönemi için altı meteoroloji istasyonundan alınan aylık toplam yağış verileri kullanılarak Doğu Karadeniz Havzası'ndaki uzun vadeli ve mevsimsel yağış dinamikleri araştırılmıştır. Çalışmada trend analiz yöntemleri arasında en güncel iki olan: Çoklu Risk Düzeyi Belirleme (MRLI) ve Trend Poligon Yıldızlama (TPSCM) yöntemleri kullanılmıştır. MRLI yaklaşımı, Kolmogorov-Smirnov testi ile doğrulanan en uygun teorik dağılımlardan türetilen kritik yağış değerlerini belirleyerek, birden fazla risk yüzdesi boyunca artan, azalan veya sabit trendlerin belirlenmesini sağlamıştır. Sonuçlar, dikkate değer bir mekansal değişkenliği ortaya koymuştur: Giresun tüm risk düzeylerinde artan trendler sergilerken, Artvin ve Trabzon farklı yüzdelikler arasında hem artan hem de azalan eğilimlerle karışık davranışlar göstermiştir. Geriye kalan istasyonlar düşük, orta ve yüksek risk sınıfları arasında değişen trend örüntüleri göstermiştir. Trend Poligon Yıldızlama yöntemi, yıllık değişkenlik ve mevsimsel geçişler hakkında önemli bilgiler sağlamıştır. Aylık yağış geçişleri, erken ve geç alt dönemler arasındaki değişiklikleri de kapsayacak şekilde dört yönlü bölgeye ayrılmıştır. Bölgelerin mekansal dağılımı, iller arasında önemli ölçüde farklılık göstermiş ve mevsimsel yağış yapısında zaman içinde değişimler meydana geldiği sonucuna varılmıştır. Bu çalışmada, MRLI ve Trend Poligonu yöntemlerinin birlikte kullanılması, uzun vadeli ve mevsimsel yağış davranışının kapsamlı bir değerlendirmesini sunmuş, Doğu Karadeniz Havzası için gelişmiş hidrolojik planlama ve iklim adaptasyon stratejilerine alt yapı hazırlamıştır.

Keywords

• MRLI
• TPSCM
• Doğu Karadeniz Havzası
• Trend Analizi
• Yağış

A Dual-Method Evaluation of Long-Term Precipitation Changes in Türkiye’s Eastern Black Sea Basin

Abstract

In this study, the long-term and seasonal precipitation dynamics of the Eastern Black Sea Basin were investigated using monthly total precipitation data from six meteorological stations for the period 1994–2024. Two contemporary trend analysis techniques—the Multi-Risk Level Identification (MRLI) method and the Trend Polygon Star Concept Method (TPSCM)—were applied to provide a comprehensive evaluation of precipitation behavior. The MRLI approach identified increasing, decreasing, or stable trends across a range of risk percentiles by determining critical precipitation thresholds from best-fitting theoretical distributions validated through the Kolmogorov–Smirnov (K-S) test. The results revealed substantial spatial variability: while Giresun exhibited consistently increasing trends at all risk levels, Artvin and Trabzon showed mixed behavior with both upward and downward tendencies depending on the percentile. In addition, a basin-wide evaluation indicated that approximately 65% of the overall trends were increasing, whereas 35% displayed decreasing tendencies, highlighting a general intensification of precipitation conditions in the region. The remaining stations showed diverse responses across low-, medium-, and high-risk classes. The TPSCM method offered further insights into intra-annual variability by categorizing month-to-month precipitation transitions into four directional regions representing shifts between early and late sub-periods. The spatial distribution of these regions varied considerably among provinces, indicating notable temporal changes in seasonal rainfall structures. Overall, the combined application of MRLI and TPSCM enabled a detailed assessment of both long-term and seasonal precipitation characteristics, providing a robust basis for advanced hydrological planning and climate adaptation strategies in the Eastern Black Sea Basin.

Keywords

• MRLI
• TPSCM
• Eastern black sea basin
• Trend analysis
• Precipitation

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