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Öğe Land use suitability analysis of rural tourism activities: Yenice, Turkey(Elsevier Sci Ltd, 2020) Kaptan Ayhan, Çiğdem; Cengiz Taşlı, Tülay; Özkök, Ferah; Tatlı, HasanIn this study, a land use suitability analysis was conducted for rural tourism in the Yenice district, located in the north-west of Turkey. As part of the research process involved dividing the area in question into landscape units using GIS and RS techniques. A suitability rating for tourism activities in each landscape unit was obtained by following through the steps of the ELECTRE method, individually repeated for each landscape unit. It is considered that the 1st-, 2nd- and 3rd-degree suitable activities were most relevant in the rating of the nine different tourism activities. Therefore assessments were made on the basis of these first three ranks. As a result of the analysis, from the 1st-degree suitable activities identified, the first three were found to be mountaineering, trekking and wildlife observation. From the 2nd-degree suitable activities, the first three were flora observation, trekking and hiking, and from the 3rd-degree suitable activities, the first three trekking, orienteering and mountaineering.Öğe Multivariate-drought indices-case studies with observations and outputs of NCAR CCSM-4 ensemble models(Springer, 2021) Tatlı, HasanThis study suggests developing a new drought index using the conditional probability of precipitation associated with a wide range of other weather variables, such as temperature, to monitor droughts. Once the marginal probability distributions of the variables become known, it is possible to determine the joint and conditional probabilities through the choice of suitable copula functions. This new drought index of the so-called conditional standardized precipitation index (CSPDI) allows for evaluation of droughts just like the standardized precipitation index (SPI). The L-Moment method was used in the application part of the study to estimate the marginal probabilities of temperature and precipitation; on the other hand, both French-Gumbel Morgenstein (FGM) and Gaussian copula types were used within the case studies to assess joint and conditional probabilities. To evaluate the potential of the proposed drought index, drought patterns were reviewed through this index across several climate zones obtained through the Holdridge Life Zone (HLZ) method. To demonstrate the proposed approach’s capabilities regarding climate change studies, the CSPDI has been applied to the production of the Community Climate System Model (CCSM-4) selected near the major provinces in the country that stand out in population, agriculture, and industrial development. In addition to this, the kriging interpolation technique has been used to embed temperature and precipitation variables recorded by the country’s meteorological stations within the same grid points as the CCSM-4 models. The spatial analysis of the drought patterns using the results of the CCSM4 models and the weather stations established at grid points in the vicinity of the five largest cities of the country provide a useful basis in terms of measuring drought conditions. All these results showed that the CSPDI results changed significantly according to the time characteristics; choosing the temperature as a secondary variable in the CSPDI calculation did not affect the drought model of a rainy weather station such as Rize. But in semi-arid regions such as Izmir and Antalya, both coastal regions, the temperature had a strong effect on drought patterns. Furthermore, the suggested methodology has been applied to the results of GCM models used with CCSM-4 built on the RCP 8.5 scenario. The precipitation and temperatures used in the CSPDI calculations were derived from the NCAR GIS climate model, which allowed the IPCC to apply the CCSM-4 simulation methods in the fifth assessment of the AR5 report.Öğe Climate classification in Turkey: a case study evaluating Holdridge life zones(Springer, 2021) Tekin, Mehmet Kadri; Tatlı, Hasan; Koç, TelatThe Holdridge life zone (HLZ) method is applied to map potential vegetation types in Turkey. The HLZ map is compared to a map of actual vegetation in order to assess the degradation status of vegetation in Turkey. Data required to identify HLZ classes are provided by the General Directorate of Meteorology, while the current vegetation status is estimated with data provided by the General Directorate of Forestry. After weather data are cleaned and missing values are replaced, the HLZ type is estimated for each station, and then thematic maps are created using the ArcGIS software. The study reveals that there are 12 HLZ types in Turkey. The three dominant types are as follows: cool temperate steppe, warm temperate dry forest, and cool temperate moist forest. In regions where physical geographical controls change in short distances, the biodiversity is greater, and linked to this, the HLZ diversity also appears to be greater. Comparing the identified life zones to the actual vegetation, in some areas, remarkable mismatches can be found. Although, in some regions, the life zone type is consistent with the land cover type, in some narrow areas, the potential vegetation does not reflect features of the current vegetation cover. Considering limitations and capabilities of the assessment approach used in this study, we think that the incompatibility between actual and modelled vegetation types in the eastern region of Turkey is caused by the intensive landscape use. The goal of this research is to support future bioclimatic studies and land use management strategies.Öğe Analysis of temporal diversity of precipitation along with biodiversity of Holdridge life zones(Springer, 2021) Tatlı, Hasan; Dalfes, H. NuzhetMany ecological studies show that diversity of vegetation is generally sensitive to hydrometeorological variables such as temperature, precipitation, and evaporation. Furthermore, it is also known that there have been changes in the precipitation regimes due to climate change and/or land use (such as urbanization). This study investigates the temporal diversity of the precipitation along with the Holdridge life zones (HLZ) using the biodiversity indices of true Hill numbers and Rényi entropy. The results show that there are no statistically significant changes in the “biodiversity” with respect to the HLZ. However, it was found that, although the biodiversity has remained more or less stable through 45 years, the HLZ classes have widened toward much warmer and drier vegetation cover. One can propose that the water regime of the rivers of the country has also changed due to the early melting of snow and an increase in evapotranspiration as a result of warming. Furthermore, using the Gini-Simpson diversity index for daily rainfall types recorded in a spatially homogeneous manner over Turkey, one can show that there are no significant changes in rainfall diversity in the coastal regions, but significant changes are observed in the internal and relatively high-altitude areas of the country.Öğe Analysis of drought intensity, frequency and trends using the spei in Turkey(Springer, 2023) Serkendiz, Hıdır; Tatlı, Hasan; Kılıç, Ayşegül; Çetin, Mahmut; Sungur, AliThis study addresses into the critical issue of drought as a natural disaster, especially in regions characterized by arid and semi-arid climates like Turkey. The primary aim of this study is to investigate the historical occurrences of meteorological drought events in Turkey, focusing on their past frequency, intensity, and spatial distribution. The study employs the Standardized Precipitation Evapotranspiration Index (SPEI) method and utilizes 50 years of monthly temperature and precipitation data collected from 222 meteorological stations across the country. Drought severity is assessed using the run theory method, and trends in drought patterns are analyzed through the Mann–Kendall trend test. Additionally, the text explores the connection between elevation and the geographical distribution of drought events. The study’s findings reveal a noticeable increase in the occurrence of drought periods over time. Among the selected periods, the most widespread drought event was observed in the year 2001. The Bozcaada meteorology station exhibited the highest frequency of drought with a value of 223, while the Ispir meteorology station recorded the lowest frequency with a value of 151. Over the course of the 50-year analysis, no significant correlation was found between drought and elevation, although a gradual increase was noted in the last 10 years. The results also indicate a gradual north-to-south increase in drought intensity in Turkey. The study identifies four distinct drought hotspots in the country: the Western Anatolia Region, Central and Southern Anatolia Region, Southeastern Anatolia Region, and Eastern Anatolia Region.Öğe Turkey: Clımate Variability, Extreme Temperature, and Precipitation(Springer Science and Business Media Deutschland GmbH, 2021) Gönençgil, Barbaros; Acar, ZahideClimate variability and climate change have significant impacts in many areas of the world with different effects. It is generally accepted that changing climate variability and consequently changes in the intensity and frequency of extreme climatic events may have strong effects on sensitive areas. The east of the Mediterranean Basin in Turkey is one area where significant effects of climate variability may be experienced. Increases in extreme hot weather events and weak but distinct decreasing tendencies in extreme cold weather events are worth noting. Therefore, the increase in temperature, which has been rising since the early 2000s, is also combined with decreases in very cold days. In addition, the decreasing tendencies in total precipitation are accepted in many weather stations as important signals of long-term drought. The increasing trend of consecutive dry days and the decreasing trend of consecutive wet days can be considered as an indication that severe precipitation events will be more pronounced in annual total precipitation.Öğe Interannual Variability of Stormy Day Over Turkey(İstanbul University Press, 2021) Kurtuluş, Yusuf Fırat; Acar, ZahideThe effects of climate variability are seen in many areas of the globe. In addition to the changes experienced in climates for many years, the variability in climate elements due to the effects of climate change in recent years is critical. In this study, spatial and temporal changes of the year to year experienced variability and trends in storm records in Turkey were examined. Also, atmospheric teleconnections that control storm frequency were examined within the scope of the study. According to the results of the study, significant reductions in recent years in the frequency of storm events are being experienced across Turkey. Stormy days show statistically significant upward trends in the interior and eastern half of Turkey. All coastal regions of Turkey, especially the western coasts and terrestrial areas in the eastern parts of the Mediterranean region experienced statistically significant downward trends. In Turkey, the NAO’s activity on the number of stormy days is quite evident in winter. NCP and frequency of storms is characterized by significant positive correlations in eastern Turkey. When evaluating the relationships between Turkey’s storm frequency and Atmospheric oscillations, one can say that NAO and AO are atmospheric oscillation indices that best explain storm frequency across the country.Öğe Konya Kapalı Havzası’nda Meteorolojik Kuraklık Analizi(İstanbul University Press, 2021) Sarış, Faize; Gedik, FurkanBu çalışmada Konya Kapalı Havzasında meteorolojik kuraklık durumu farklı zamansal ölçeklerde, 20 ayrı yağış serisi oluşturularak Standartlaştırılmış Yağış İndisi (SPI) yöntemiyle analiz edildi. Havzada yer alan 11 meteoroloji istasyonunun 1930-2019 yılları arasında değişik uzunluklarda kaydedilmiş aylık toplam yağış verileri kullanıldı. Veri setleri kısa süreli (aylık, mevsimlik ve 6 aylık) ve uzun süreli (12, 24 ve 36 aylık) yağış serileri olarak hazırlandı ve SPI hesaplamasından sonra Gidişler Sınaması uygulanarak, kuraklık indis değerlerindeki ısrar bileşeni istatistiksel olarak belirlendi. Konya Kapalı Havzasında farklı sınıflara (hafif, orta, şiddetli ve aşırı kurak) göre kuraklığın şiddeti değerlendirildi. Orta, şiddetli ve özellikle aşırı kuraklığın belirgin olduğu dönemler Aralık, Kış, 6 aylık ve daha uzun süreli (12, 24, 36 aylık) dönemlerdir. Gidişler sınaması sonucunda, tüm istasyonların 24 ve 36 aylık serilerin SPI değerlerinin istatistiksel olarak anlamlı olduğu belirlendi. Kurak dönemler açısından istasyonlar arasında bazı farklılıklar gözlense de, genel olarak havza da kurak dönemlerin yaklaşık olarak 10’ar yıllık aralıklarla gerçekleştiği belirtilebilir. 12 Aylık dönem için Cihanbeyli, Beyşehir, Ereğli ve Niğde; 24 aylık dönemde Aksaray, Karaman, Seydişehir ve Çumra; 36 aylık dönemin indis sonuçlarına göre ise Konya, Kulu ve Karapınar en fazla kurak yıl sayısına sahiptir. Uzun süreli kuraklıklardaki bu anlamlı eğilimler Konya Kapalı Havzasında meteorolojik kuraklığın, tarımsal ve hidrolojik kuraklığa doğru yayıldığını ve buna bağlı olarak havzanın su yenilenmesi açısından kırılganlığını açık bir şekilde gösterir.
