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    Determination of drought intensity in Seyhan and Ceyhan River Basins, Turkey, by hydrological drought analysis
    (Springer Wien, 2020) Altin, Turkan Bayer; Saris, Faize; Altin, Bekir Necati
    This paper studied hydrological drought identified by the Streamflow Drought Index (SDI) at eight river-gauging stations in the Eastern Mediterranean part of Turkey for a roughly 43-year period covering from 1972 to 2014 (4 stations), from 1973 to 2015 (2 stations), and from 1969 to 2011 (2 stations). Results of SDI analyses indicate that the number of drought years was highest during the 3-month October-December period. A considerable part of the drought years was determined to be mild drought. Although moderate drought conditions were observed in all stations, moderate drought conditions were determined especially at Goksu-H in the Seyhan River Basin and Sogutlu and Savrun in the Ceyhan River Basin. Short-term fluctuations of dry and wet conditions are the dominant pattern for most of the stations; however, long-term persistent drought conditions are also prominent, especially at Tacin and Korkun in Seyhan Basin and Goksun in Ceyhan Basin. The starting point for the negative trend in the 12-month series was the years 1996, 1999, and 2000.
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    Late pleistocene glacial history of Mount Karadag, SW Turkiye
    (Elsevier, 2024) Bayrakdar, Cihan; Cilgin, Zeynel; Saris, Faize; Yesilyurt, Serdar; Keserci, Ferhat; Buyukdeniz, Yusuf; Halis, Onur
    Glacial landforms in the southwestern part of the Anatolian Peninsula are found at lower elevations than the rest, suggesting that glaciers were present during the Late Pleistocene. Karadag, located west of the Western Taurus Mountains, provides evidence of the climatic conditions that facilitated this extensive glaciation. It is characterized by numerous peaks exceeding 2300 m above sea level (asl), with the highest peak reaching 2418 m, making it the region's largest glaciation area. This high mountain mass is composed mainly of limestone and dolomite. This study focuses on the glacial landforms in Karadag to reconstruct the Late Pleistocene glacial chronology and palaeoclimate of the Western Taurus Mountains. We employed detailed UAV photogrammetry, extensive fieldwork and mapping, surface exposure dating with cosmogenic 36Cl, meteorological measurements, palaeoglacier reconstruction, and palaeo-equilibrium line altitude (pELA) calculations. Karadag, a topographic barrier to humid air masses from the Mediterranean Sea, ranks as the second wettest area in the Western Taurus Mountains. At a meteorological station we installed in Karadag, an annual precipitation of 1700 mm or more was recorded, highlighting its significant precipitation. In Karadag, we have identified two glacial valleys with a maximum length of 4.5 km and six cirques. The glaciers reached their maximum extent around 22.4 f 2.8 ka during the Last Glacial Maximum (LGM), facilitated by the lowering of the pELA to 2090 m. During the LGM, the glaciers covered an area of approximately 3.5 km2 and reached a maximum thickness of about 140 m. Sample TRKR 10 at 2015 m probably belongs to the LGM period. Although a single sample does not conclude definitive conclusions, the presence of the moraine at its highest position indicates the maximum thickness of the glacier. Following the LGM, two more significant glacier advances occurred during the Lateglacial (15.5 f 2.7 ka) and the Younger Dryas (12.4 f 1.1 ka). During the late Pleistocene glaciations, and especially during the LGM, Karadag probably received more precipitation than today, leading to the formation of glaciers at relatively lower elevations than on the Anatolian Peninsula.
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    Low flow analysis in Porsuk Creek Basin
    (Istanbul Univ, Fac Letters, Dept Geography, 2016) Saris, Faize
    Identifying low flow characteristics in a basin can support meeting water demand by without endangering aquatic ecosystems and by considering water potential of the basin during dry periods. Low- flow analysis is a significant tool that provides information about the period and magnitude of water shortage. This study aims to identify long-term variability of low flows in terms of threshold value, duration and seasonality by analyzing daily streamflow data of 4 gauging stations in Porsuk Creek Basin for the period 1969-2011. Descriptive statistics were employed together with flow duration curve (for Q90 threshold) and Streamflow Deficit Index (SDI) analysis. Threshold values differ between upper and lower parts of the Porsuk Creek basin. Temporal analysis indicated that threshold values tend to decrease and in addition to this low flow periods are starting earlier. These results are not only related with decreasing of precipitation amount and changing in precipitation type but also connected with water use in the basin.
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    Physical Geography in Turkey: An Empirical Analysis of Changing Disciplinary Practices
    (Marmara Univ, 2017) Bekaroglu, Erdem; Saris, Faize
    The aim of this study, as a disciplinary review, is to question the changing disciplinary practices of Turkish physical geography in a historical and empirical context. Four data sets (performances of physical geography publications in geography journals in Turkey, number of Ph.D. thesis made in physical geography, performances of geomorphology articles in the local earth science journals, performances of Turkish physical geography articles in the SCI-SSCI data base) are used in this study. Results show that, on one hand, Turkish physical geography dominated the whole discipline until the mid-1990s but afterwards the sub-discipline gradually became the small partner of geography in Turkey. On the other hand, Turkish physical geography practices simply ignored the quantitative revolution developed firstly in the Anglo-American geography by the time of 1960s, and reproduced its descriptive, pure empiricists and map-making practices onwards. While Turkish physical geography has had a very low publication records in local earth science journals as well as international journals, by 2005; it has been observed a relatively sharp upward trend in the rate of international publication records of Turkish physical geography since that time. This trend, however, is mostly actor-depended and does not indicate any institutional restructuring occurred in the discipline. The study concludes that, apart from its Anglo-American counterparts, Turkish physical geography has its own disciplinary context. Such a context shows that physical geography has been getting smaller in the discipline and also has not renewed its institutional structure considerably and also its international publication records depend mostly on the national/international collaboration in which Turkish partners take a small part. Such a complex disciplinary pattern clearly shows that Turkish geography, now, is represented by non-physical geographers locally while international disciplinary representation is made by physical geographers.
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    Pleistocene Glaciations in Karadag, Western Taurus Mountains, Turkey
    (Tmmob Jeoloji Muhendisleri Odasi, 2017) Bayrakdar, Cihan; Cilgin, Zeynel; Saris, Faize
    Karadag is one of the mountains subjected to the Pleistocene glaciations in the Teke Peninsula (Western Taurus) along with Beydaglari, Akdag, and Sandiras Mountains. Karadag, which reaches 2418 m summit at a 30 km straight distance from the northeast of Fethiye Bay, has many peaks over 2300 m. There are plenty of glacial researches and dating studies aim to reveal Pleistocene glaciation chronology of the mountains such as Sandiras and Akdag in the Teke Peninsula. On the other hand, glaciations in Beydaglari were mentioned superficially and in general terms. Lastly, there has not been known any glaciation phenomenon in Karadag, in other words there are not any studies concerning the glaciation on the mountain. However, Karadag has distinctive cirques and moraines on the slopes of high elevations near the peak. In this study, we identified glacial valleys, cirques developed in different sizes and aspects and lastly frontal and hummocky moraines in front of these cirques. They are descending to the elevation of 1800 m. With this study, a new glacial area was identified in Turkey and made a contribution to the glaciation inventory of Turkey. This study aims to reveal the geomorphological and climatological characteristics of this area with regard to tectonic, climatic and karstic characteristics during Pleistocene. Maps and relevant outputs were created and analyzed by geographic information systems using the spatial data obtained from the field studies, unmanned aerial vehicles and meteorological stations.
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    Spatial variability of precipitation regimes over Turkey
    (Taylor & Francis Ltd, 2010) Saris, Faize; Hannah, David M.; Eastwood, Warren J.
    Turkish annual precipitation regimes are analysed to provide a large-scale perspective and redefine precipitation regions. Monthly total precipitation data are employed for 107 stations (1963-2002). Precipitation regime shape (seasonality) and magnitude (size) are classified using a novel multivariate methodology. Six shape and five magnitude classes are identified, which exhibit clear spatial structure. A composite (shape and magnitude) regime classification reveals dominant controls on spatial variability of precipitation. Intra-annual timing and magnitude of precipitation is highly variable due to seasonal shifts in Polar and sub-Tropical zones and physiographic factors. Nonetheless, the classification methodology is shown to be a powerful tool that identifies physically-interpretable precipitation regions: (1) coastal regimes for Marmara, coastal Aegean, Mediterranean and Black Sea; (2) transitional regimes in continental Aegean and Southeast Anatolia; and (3) inland regimes across Central and Eastern Anatolia. This research has practical implications for understanding water resources, which are under ever growing pressure in Turkey.
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    Spatiotemporal variability of precipitation total series over Turkey
    (Wiley, 2009) Turkes, Murat; Koc, Telat; Saris, Faize
    Long-term changes and trends in the series of monthly, seasonal and annual precipitation totals of 97 stations in Turkey were analysed by considering their spatial and temporal characteristics. Secular trends in precipitation series were examined with the Mann-Kendall rank correlation test for the general period 1930-2002, whereas spatial variabilities of, and relationships between, the precipitation series at 86 of these stations were investigated by the principal component analysis (PCA) for the period 1953-2002 when the length of data is at its best for the stations subjected to the PCA. Major findings of the paper can be summarized as follows: (1) First principal component (PC1) generally describes climatology of the precipitation totals in Turkey that is closely governed by the large-scale and/or synoptic scale atmospheric features (i.e. surface and upper air pressure and wind systems). (2) In winter, it is very likely that the greater PC1 loadings over the western and south-western parts of Turkey characterized mainly with the Mediterranean rainfall regimes indicate influence of the large-scale atmospheric circulation and associated weather patterns. However, smaller PC1 loadings over the north-eastern and eastern parts of Turkey are very likely related to the influence of the northerly mid-latitude cyclones, and the northerly and easterly circulations linked with the Eastern Europe and the Siberian originated high pressures on spatial variations of winter precipitation. (3) As for the long-term temporal variability, it was detected that there is an apparent decreasing trend in the winter precipitation totals of Turkey, whereas a general increasing trend is dominant in the precipitation totals of spring, summer and autumn seasons. (4) Observed decreasing trends are the strongest over the Mediterranean and the Mediterranean Transition rainfall regime regions. (5) Strong decreasing trends are also mostly found in winter months of the year, while apparent increasing trends show up at some stations in the months of April, August and October. Copyright (c) 2008 Royal Meteorological Society
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    The spatial pattern of selected extreme precipitation indices for Turkey (1975-2012)
    (Sciendo, 2020) Saris, Faize
    This paper analyses extreme precipitation characteristics of Turkey based on selected WMO climate change indices. The indices - monthly total rainy days (RDays); monthly maximum 1-day precipitation (Rx1day); simple precipitation intensity index (SDII); and monthly count of days when total precipitation (represented by PRCP) exceeds 10 mm (R10mm) - were calculated for 98 stations for the 38-year overlapping period (1975-2012). Cluster analysis was applied to evaluate the spatial characterisation of the annual precipitation extremes. Four extreme precipitation clusters were detected. Cluster 1 corresponds spatially to Central and Eastern Anatolia and is identified with the lowest values of the indices, except rainy days. Cluster 2 is concentrated mainly on the west and south of Anatolia, and especially the coastal zone, and can be characterised with the lowest rainy days, and high and moderate values of other indices. These two clusters are the most prominent classes throughout the country, and include a total of 82 stations. Cluster 3 is clearly located in the Black Sea coastal zone in the north, and has high and moderate index values. Two stations on the north-east coast of the Black Sea region are identified as Cluster 4, which exhibits the highest values among all indices. The overall results reveal that winter months and October have the highest proportion of precipitation extremes in Turkey. The north-east part of the Black Sea region and Mediterranean coastal area from the south-west to the south-east are prone to frequent extreme precipitation events.