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    Climatic and social change during the Little Ice Age in Cappadocia Vicinity, Southern Central Anatolia, Turkey
    (Springer Heidelberg, 2020) Bayer Altin, Turkan; Kaya, Mehmet
    This study presents the effects of the Little Ice Age (LIA) from ca. 1300 to the mid-nineteenth century in the Cappadocia Vicinity, Turkey and surrounding area. Using historical and geographic data, it focuses on important social-economic problems during the cold period corresponding to the LIA and also the small-scale glacial expansion of Aladaglar Mts. south of Nigde. Archive records of the vicinity together with the literature were examined, and significant historical events were determined. A digital elevation model (DEM) map was drawn up from 1/25,000-scale topographical maps of the Aladaglar Mts. and aerial photos. Socio-economic problems such as drought, famine, breakdown in public order, and epidemics occurred around Cappadocia during the LIA, along with transportation difficulties due to heavy snowfall. Moraines on the Aladaglar Mts. that were created by the deposition of glacial melts are striking due to their newly formed appearance and are located immediately behind the old moraines and on valley slopes at elevations between 3000 and 3100 m. These moraines have advanced 20-50 m along the valleys. The small-scale advance of glaciers in mountainous areas, hardships caused by colder conditions in the lowlands, and difficulties of human adaptation are all important indicators of the LIA.
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    CLIMATIC AND TECTONIC EFFECTS ON TERRACE FORMATION DURING THE LATE QUATERNARY IN THE UPPER YESILIRMAK VALLEY, NORTHERN TURKEY
    (Comitato Glaciologico Italiano, 2017) Bayer Altin, Turkan; Necati Altin, Bekir; Zeynel Ozturk, Muhammed
    This study was carried out in the upper course of the Yesilirmak River, which is one of the biggest rivers reaching the Black Sea, northern Turkey. We distinguished two fluvial terraces and dated them using OSL technique. T2 is the young terrace and situated at similar to 11 m above the actual river (at 620 m asl). T1 is the youngest and situated at similar to 5-6 m above the actual river (at 605 m asl). From the lower dated terrace (T1) was dated 6735 ka, 5277 ka and 4226 ka, respectively. From the higher dated terrace (T2) was dated 24,139 ka, 22,008 ka, 12,694 ka and 11,307 ka, respectively. While the higher terrace aggraded during three important cold periods (Heinrich 2 event (H2), the Last Glacial Maximum (LGM) and the Younger Dries (YD), the lower terrace (the present floodplain) aggraded during the Holocene Climatic Optimum (HCO). The river incised during transition from the LGM to Holocene transition and after the HCO. the Yesilirmak has incised its valley similar to 11 m during the last 24 ka. These results indicate an average incision rate of 1.25 mm/yr (1.25 m/ka).
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    Response of hydrological drought to meteorological drought in the eastern Mediterranean Basin of Turkey
    (Springer Heidelberg, 2021) Bayer Altin, Turkan; Altin, Bekir N.
    The hydrographic eastern Mediterranean Basin of Turkey is a drought sensitive area. The basin is an important agricultural area and it is necessary to determine the extent of extreme regional climatic changes as they occur in this basin. Pearson's correlation coefficient was used to show the correlation between standardized precipitation index (SPI) and standardized streamflow index (SSI) values on different time scales. Data from five meteorological stations and seven stream gauging stations in four sub-basins of the eastern Mediterranean Basin were analyzed over the period from 1967 to 2017. The correlation between SSI and SPI indicated that in response to meteorological drought, hydrological drought experiences a one-year delay then occurs in the following year. This is more evident at all stations from the mid-1990s. The main factor causing hydrological drought is prolonged low precipitation or the presence of a particularly dry year. Results showed that over a long period (12 months), hydrological drought is longer and more severe in the upper part than the lower part of the sub-basins. According to SPI-12 values, an uninterrupted drought period is observed from 2002-2003 to 2008-2009. Results indicated that among the drought events, moderate drought is the most common on all timescales in all sub-basins during the past 51 years. Long-term dry periods with moderate and severe droughts are observed for up to 10 years or more since the late 1990s, especially in the upper part of the sub-basins. As precipitation increases in late autumn and early winter, the stream flow also increases and thus the highest and most positive correlation values (0.26-0.54) are found in January. Correlation values (ranging between -0.11 and -0.01) are weaker and negative in summer and autumn due to low rainfall. This is more evident at all stations in September. The relation between hydrological and meteorological droughts is more evident, with the correlation values above 0.50 on longer timescales (12- and 24-months). The results presented in this study allow an understanding of the characteristics of drought events and are instructive for overcoming drought. This will facilitate the development of strategies for the appropriate management of water resources in the eastern Mediterranean Basin, which has a high agricultural potential.