Estimation and Analysis of Seasonal Rainfall Distribution and Potential of Türkiye and Its 25 Main Watersheds

Abstract

In this study, the seasonal rainfall distribution in Türkiye and its 25 main watersheds were estimated, and potentials were calculated and analyzed. Empirical Bayesian kriging (EBK) and ordinary kriging (OK) methods were applied in interpolations. The calculations were made through EBK, which provided the highest estimation accuracy in all seasons. In winter, which is the season with the highest rainfall, Türkiye’s rainfall depth is 208.8 mm, and its volume is 162.87 billion m3. In summer, the season with the lowest rainfall, Türkiye’s rainfall depth is 61.7 mm, and its volume is 48.13 billion m3. The watersheds with the highest rainfall depth are Antalya (480.1 mm) in winter, Ceyhan (222.8 mm) in spring, and East Black Sea in summer (197.5 mm) and autumn (299.7 mm). Conversely, the watersheds with the lowest precipitation depth are Aras (74.9 mm) in winter, Little Meander (16.5 mm) in summer, and Konya in spring (131.3 mm) and autumn (86.2 mm). In summer, rainfall shortage is observed in all watersheds in the Central and Southern parts of Türkiye. As we go from the north to the south, the watersheds’ seasonal rainfall depths and shares become more irregular and variable.

Analysis of Monthly Precipitation at the Basin Scale in Türkiye

“…Considering the high variability of the spatial distribution of monthly precipitations in Türkiye, the performances of OK and IDW methods are also adequate (Moriasi et al, 2007). The increased number of stations also increased the performance of these methods (Dirks et al, 1998;Borges et al, 2016;Frazier et al, 2016;Hurtado et al, 2021;Aksu, 2021, Aksu, 2023.…”

“…There are papers in Türkiye, in which deterministic and geostatistical techniques were used or compared for the interpolation of rainfall data (Türkoğlu et al, 2016;Çıtoğlu et al, 2017;Raja et al, 2017;Aksu, 2021;Aksu, 2023) Monthly rainfall data provide more correct intra-yearly rainfall knowledge than annual and seasonal rainfall data. Only annual assessments of precipitation distribution may hide months of the year with precipitation shortages.…”

“…Monthly rainfall information is an element that makes significant additions to the monitoring of drought and climate change, basin and water resources management, and agricultural and hydrological practices. Although there are many studies investigating the annual and seasonal potential and variability of precipitation in Türkiye (Kadıoğlu et al, 1999;Türkeş et al, 2009;Çiçek and Duman 2015;Raja et al, 2017;Türkeş, 2020a;Aksu, 2021, Aksu, 2023. There is no study in the literature explaining the watershed-based monthly potential and spatial distribution of precipitation.…”

Türkiye'de Yağış Ölçer Ağı Yoğunluğunun Yağış Dağılımı Modellemesine Etkisinin Değerlendirilmesi: Antalya Havzası Örneği

“…Literatürde MGM ve DSİ yağış verilerinin birlikte kullanıldığı çalışmalar vardır (Çetin & Tülücü, 1997;Aksu & Güngör, 2020;Aksu, 2023a;Aksu, 2023b). Fakat MGM verileriyle oluşturulan yağış deseni ile MGM ve DSİ istasyonlarının birlikte kullanılarak oluşturulan yağış desenlerinin karşılaştırıldığı bir çalışma bulunmamaktadır.…”

“…Havzanın Kovada Gölünün kuzeyinde bulunan alanlarında ise Akdeniz geçiş (Akdeniz'den İç Anadolu'ya) iklim özellikleri olan orta yağışlı bir kış ve ilkbahar hüküm sürmektedir (Türkeş, 2010). Havza yıllık ortalama yağışının %23'ünü ilkbahar, %4,4'ünü yaz, %21,4'ünü sonbahar ve %51,2'sini kış mevsiminde almaktadır (Aksu, 2023a). Havzada sıcaklık güneyden kuzeye ve yükseklikte azalmaktadır.…”