EVALUATION OF KRIGING WITH EXTERNAL DRIFT METHOD IN SPATIAL MODELLING OF PRECIPITATION: A CASE OF AEGEAN REGION, TURKEY

Öz

The structures and geographical formations observed in the Aegean region of Turkey differ from the other coastal regions of the country. Especially, elevation and aspect have different characteristics in this region. Thus, the precipitation conditions are influenced and the annual precipitation amounts observed in the plains are not consistent. In this study, Kriging with an External Drift was applied to obtain a prediction map of precipitation in the Aegean region. Annual mean total precipitation data obtained from 36 stations (1976–2010) were used. Elevation was used as a secondary variable in Kriging with an External Drift calculations. The R² of 0.35 shows that at least one quarter of the precipitation behaviour can be explained by the model. A distribution that complies with the orographic extension draws attention in the Kriging with an External Drift precipitation estimation map. The results show that Kriging with an External Drift and incorporation of elevation as a secondary variable could be used to supplement sparse observations in the mapping of precipitation.

Anahtar Kelimeler

• precipitation,elevation,geostatistics

YAĞIŞIN MEKÂNSAL OLARAK MODELLENMESINDE KRIGING WITH EXTERNAL DRIFT YÖNTEMININ DEĞERLENDIRILMESI:EGE BÖLGESI

Öz

TEge Bölgesi’nde görülen coğrafi oluşumlar ve yapılar, Türkiye’nin diğer kıyı bölgerinden farklılık göstermektedir. Özellikle bu bölgedeki yükseklik ve bakı, farklı karekteristiklere sahiptir. Bu nedenle, yağış durumu etkilenmektedir ve düzlük alanlarda görülen yıllık yağış miktarlarında bir istikrar gözlenmemektedir. Bu çalışmada, Ege Bölgesi’nde yağış haritası tahmini için Kriging with External Drift yöntemi kullanılmıştır. Çalışmada 36 istasyonda 1976–2010 yıllarında ölçülmüş aylık ortalama yağış değerlerinden elde edilen yıllık toplam yağış verisi kullanılmıştır. Yağış tahmininde yardımcı değişken olarak yükseklik verisinden yararlanılmıştır. Kriging with External Drift yağış tahmin haritasında orografik uzanımlar ile uyumlu bir dağılım dikkat çekmektedir. Sonuçlar, yüksekliğin yardımcı değişken olarak kullanıldığı Kriging with External Drift analizinin seyrek gözlemlerin olduğu yerlerin yağış haritalarının oluşturulmasına yardımcı bir yöntem olduğunu göstermiştir. 

Anahtar Kelimeler

• Yağış,Yükseklik,Jeoistatistik,Kriging with External Drift

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