Environmental Risk Analysis of Turkey under Climate Change Scenarios using Spatial Modelling: Application of Net Primary Productivity

Öz

The aim of this study is to estimate the response of NPP to regional climate changes in Turkey using a biogeochemical modelling approach. The CASA model was utilized to predict annual regional fluxes in terrestrial net primary production for present (2000-2010) and future (2060-2080) climate conditions. A comprehensive data set including percentage of tree cover, land cover map, soil texture, NDVI (Normalized Difference Vegetation Index) and climate variables were used to constitute the model. The multi-temporal metrics were produced using 16 days MODIS composites with 250 m spatial resolution. The future climate projections were based on a RCP (Representative Concentration Pathways) scenario that was defined in 5th Assessment Report of IPCC. In this context, the future NPP modelling was performed with prescribed CO2 concentrations up to 421 ppm and temperature increasing 1.1ºC to 2.0ºC.

The model results indicated that the NPP in Turkey averages 1232 gCm2y-1. Terrestrial NPP ranges from 9.61 to 316.1 gCm2y-1 for the baseline period (2000-2010). Modeled total NPP averages 1320.8 gCm2y-1 per year in the period 2060-2080. Total carbon budget of NPP was estimated as 104.78 MT (million tons) per year. The model results showed that the terrestrial NPP was sensitive to changes in temperature and precipitation. Addressing the model results, the CASA provided a great potential to predict present and future productivity on regional basis. Thus, this study will provide a scientific foundation to understand and assess ecological and economic implications and consequences of climate change on the productivity in Turkey.

Anahtar Kelimeler

• NPP,Modelling,Climate change,Turkey,MODIS,IPCC,RCPs

İklim Değişikliği Senaryoları Altında Konumsal Modelleme Kullanarak Türkiye’nin Çevresel Risk Analizi: Net Birincil Üretim Örneği

Öz

Çalışmanın amacı, Türkiye‟de bölgesel iklim değişikliğinin Net Birincil Üretim (NPP)‟e etkilerinin biyokimyasal modelleme yaklaşımı ile tahmin edilmesidir. Güncel (2000-2010) ve gelecek (2060-2080) iklim koşullarında karasal NPP‟in yıllık bölgesel döngülerinin tahmininde CASA modeli kullanılmıştır Modelin oluşturulmasında ağaç kapalılık yüzdesi, arazi örtüsü, toprak tekstürü, Normalleştirilmiş Fark Vejetasyon İndeksi (NDVI) ve iklim değişkenlerinden oluşan geniş bir veri seti kullanılmıştır. Çoklu zamansal metrikler 250 m çözünürlü MODIS verileri kullanılarak üretilmiştir. Gelecek tahmini için IPCC‟nin 5. Değerlendirme Raporunda tanımlanan RCP (Representative Concentration Pathways) senaryoları baz alınmıştır. Bu kapsamda, 1,1ºC ile 2,0ºC arasında sıcaklık ve 421 ppm‟e kadar CO2 artışı limit alınmıştır.

Model sonuçları, Türkiye için ortalama NPP değerinin 1232 gCm2y-1 olduğunu göstermiştir. Karasal NPP güncel durum için 9,61 to 316,1 gCm2y-1 değişmektedir. Modellenen yıllık toplam NPP ise 2060-2080 yılları için 1320,8 gCm2y-1‟dir. Toplam karbon bütçesi yıllık 104,78 milyon ton tahmin edilmiştir. Model sonuçları karasal NPP‟nin sıcaklık ve yağış değişimlerine hassas olduğunu göstermiştir. CASA modeli, güncel ve gelecek NPP değerlerinin hesaplanmasında bölgesel temelde başarılı sonuçlar vermiştir. Bu çalışma, Türkiye‟de iklim değişikliği altında ekolojik ve ekonomik sonuçların ortaya konması yardımcı veriler üretilmesi bakımından önem taşımaktadır.

Anahtar Kelimeler

• NPP,Modelleme,İklim değişimi,Türkiye,MODIS,IPCC,RCP

Kaynakça

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