Search

Water resources in semi-arid regions like the Mediterranean Basin are highly vulnerable because of the high variability of weather systems. Additionally, climate change is altering the timing and pattern of water availability in a region where growing populations are placing extra demands on water supplies. Importantly, how reservoirs and dams have an influence on the amount of water resources available is poorly quantified. Therefore, we examine the impact of reservoirs on water resources together with the impact of climate change in a semi-arid Mediterranean catchment. We simulated the Susurluk basin (23.779-km(2)) using the Soil and Water Assessment Tool (SWAT) model. We generate results for with (RSV) and without reservoirs (WRSV) scenarios. We run simulations for current and future conditions using dynamically downscaled outputs of the MPI-ESM-MR general circulation model under two greenhouse gas relative concentration pathways (RCPs) in order to reveal the coupled effect of reservoir and climate impacts. Water resources were then converted to their usages - blue water (water in aquifers and rivers), green water storage (water in the soil) and green water flow (water losses by evaporation and transpiration). The results demonstrate that all water resources except green water flow are projected to decrease under all RCPs compared to the reference period, both long-term and at seasonal scales. However, while water scarcity is expected in the future, reservoir storage is shown to be adequate to overcome this problem. Nevertheless, reservoirs reduce the availability of water, particularly in soil moisture stores, which increases the potential for drought by reducing streamflow. Furthermore, reservoirs cause water losses through evaporation from their open surfaces. We conclude that pressures to protect society from economic damage by building reservoirs have a strong impact on the fluxes of watersheds. This is additional to the effect of climate change on water resources.

In this study, projected future changes for the period of 2020 – 2050 in mean air temperature and precipitation climatology and year-to-year variability with respect to the control period of 1970 – 2000 were investigated for the domain of Turkey via regional climate model simulations. In order to investigate the projected changes in near future climate conditions, Regional Climate Model (RegCM4.3.5) of ICTP (International Centre for Theoretical Physics) was driven by three different global climate models. HadGEM2 global climate model of the Met Office Hadley Centre, MPI-ESM-MR global climate model of the Max Planck Institute for Meteorology, GFDL-ESM2M global climate model of the National Oceanic and Atmospheric Administration Geophysical Fluid Dynamics Laboratory were dynamically downscaled to 50 km for Turkey and its surrounding region. The projections were performed based on the RCP4.5 and the RCP8.5 emission scenarios of the Intergovernmental Panel on Climate Change (IPCC). According to the model results, there will be an increase between 0.5 °C and 4 °C in mean air temperatures of Turkey for the period of 2020 – 2050 with respect to the period of 1970 – 2000. This warming will be more severe in warm seasons than cold seasons. Precipitation decreases varying from approximately 0.4 mm/day to 1.2 mm/day in precipitation climatology of Turkey are expected to occur in all seasons particularly over the southern and western regions of the country dominated by the Mediterranean climate, according to the regional climate model results.Keywords: Turkey, climate change, emission scenarios, regional climate model simulation, future climate projections., Bu çalışmada 1970 – 2000 referans dönemi iklimine göre 2020 – 2050 dönemi için Türkiye’nin ortalama hava sıcaklığı ve yağış klimatolojilerinde öngörülen değişiklikler, bölgesel iklim modeli benzetimleri kullanılarak araştırıldı. Yakın gelecekteki iklim koşullarında öngörülen değişimleri incelemek için Uluslararası Teorik Fizik Merkezi’ne ait olan RegCM4.3.5 isimli bölgesel iklim modeli üç farklı küresel modelden yararlanılarak koşuldu. Max Planck Meteoroloji Enstitüsü’ne ait MPI-ESM-MR, Met Office Hadley Merkezi’ne ait HadGEM2 ve Amerikan Ulusal Okyanus ve Atmosfer Dairesi Jeofiziksel Akışkanlar Dinamiği Laboratuvarı’na ait GFDL-ESM2M modelleri Türkiye ve çevresi için dinamik olarak 50 km’ye alt ölçeklendirildi. Öngörüler, Hükümetlerarası İklim Değişikliği Paneli’nin (IPCC) RCP4.5 ve RCP8.5 salım senaryolarına göre gerçekleştirildi. Model sonuçlarına göre, Türkiye’de ortalama hava sıcaklıklarında 1970 – 2000 dönemine göre 2020 – 2050 döneminde 0.5 °C ile 4 °C arasında değişen artışlar olacaktır. Bu artış, sıcak mevsimlerde soğuk mevsimlere göre daha fazla olacaktır. Türkiye’nin yağış klimatolojisinde ise, bölgesel iklim modeli sonuçlarına göre, özellikle ülkenin Akdeniz ikliminin egemen olduğu batı ve güney bölgelerinde ve tüm mevsimlerde, yaklaşık 0.4 mm/gün ile 1.2 mm/gün arasında değişen belirgin yağış azalışlarının oluşması beklenir.Anahtar kelimeler: Türkiye, iklim değişikliği, salım senaryoları, bölgesel iklim modeli benzetimi, gelecek iklim kestirimi.

Bu çalışmada 1970 – 2000 referans dönemi iklimine göre 2020 – 2050 dönemi için Türkiye’nin ortalama hava sıcaklığı ve yağış klimatolojilerinde öngörülen değişiklikler, bölgesel iklim modeli benzetimleri kullanılarak araştırıldı. Yakın gelecekteki iklim koşullarında öngörülen değişimleri incelemek için Uluslararası Teorik Fizik Merkezi’ne ait olan RegCM4.3.5 isimli bölgesel iklim modeli üç farklı küresel modelden yararlanılarak koşuldu. Max Planck Meteoroloji Enstitüsü’ne ait MPI-ESM-MR, Met Office Hadley Merkezi’ne ait HadGEM2 ve Amerikan Ulusal Okyanus ve Atmosfer Dairesi Jeofiziksel Akışkanlar Dinamiği Laboratuvarı’na ait GFDL-ESM2M modelleri Türkiye ve çevresi için dinamik olarak 50 km’ye alt ölçeklendirildi. Öngörüler, Hükümetlerarası İklim Değişikliği Paneli’nin (IPCC) RCP4.5 ve RCP8.5 salım senaryolarına göre gerçekleştirildi. Model sonuçlarına göre, Türkiye’de ortalama hava sıcaklıklarında 1970 – 2000 dönemine göre 2020 – 2050 döneminde 0.5 °C ile 4 °C arasında değişen artışlar olacaktır. Bu artış, sıcak mevsimlerde soğuk mevsimlere göre daha fazla olacaktır. Türkiye’nin yağış klimatolojisinde ise, bölgesel iklim modeli sonuçlarına göre, özellikle ülkenin Akdeniz ikliminin egemen olduğu batı ve güney bölgelerinde ve tüm mevsimlerde, yaklaşık 0.4 mm/gün ile 1.2 mm/gün arasında değişen belirgin yağış azalışlarının oluşması beklenir. In this study, projected future changes for the period of 2020 – 2050 in mean air temperature and precipitation climatology and year-to-year variability with respect to the control period of 1970 – 2000 were investigated for the domain of Turkey via regional climate model simulations. In order to investigate the projected changes in near future climate conditions, Regional Climate Model (RegCM4.3.5) of ICTP (International Centre for Theoretical Physics) was driven by three different global climate models. HadGEM2 global climate model of the Met Office Hadley Centre, MPI-ESM-MR global climate model of the Max Planck Institute for Meteorology, GFDL-ESM2M global climate model of the National Oceanic and Atmospheric Administration Geophysical Fluid Dynamics Laboratory were dynamically downscaled to 50 km for Turkey and its surrounding region. The projections were performed based on the RCP4.5 and the RCP8.5 emission scenarios of the Intergovernmental Panel on Climate Change (IPCC). According to the model results, there will be an increase between 0.5 °C and 4 °C in mean air temperatures of Turkey for the period of 2020 – 2050 with respect to the period of 1970 – 2000. This warming will be more severe in warm seasons than cold seasons. Precipitation decreases varying from approximately 0.4 mm/day to 1.2 mm/day in precipitation climatology of Turkey are expected to occur in all seasons particularly over the southern and western regions of the country dominated by the Mediterranean climate, according to the regional climate model results. Publisher's Version