Landslide-Triggering Factors in Korucak Subbasin, North Anatolian, Turkey

AbstractKorucak Creek Basin is located within upper course of the Yeşilırmak River Basin and southern Middle Karadeniz (Black Sea) section which is known to have the potential of landslide and flood risk. The purpose of identification of landslide-triggering factors is to highlight the regional distribution of potentially unstable slopes and to guide decision makers for regional planning purposes. We assessed morphometric parameters for landslide-triggering factors of Korucak Creek Basin using GIS (Geographical Information System). These parameters are Stream Power Index (SPI) and Compound Topographic Index (CTI). Moreover, slope and elevation values of the basin were classified and superposed over the geologic map. Landslide locations were identified from topographic maps and verified with field observation. The total catchment area of the basin is about 55 km2. More than half of the total basin is covered by metamorphic rock types such as schist, which has high permeability and weakness against erosion and is one of the main causes of the landslides. The results show that the main triggering factors are slope and lithology. Thus, northern and western of the Korucak subbasin are under the highest-risk landslide areas

Distribution of Pleateaus (Yayla) and Sheep-barns According to Topographic Factors Around Melendiz and Hasan Mountains

Aksaray-Niğde illeri arasındaki Hasandağı ve Melendiz Dağı çevresindeki ağılların ve yaylaların topografik faktörlere (yükselti, eğim ve bakı) göre dağılışı incelenmiştir. GPS ile belirlenen ağıl ve yaylalar sayısallaştırılmış 1/25000 ölçekli topografya haritaları üzerine yerleştirilerek bunların topografik birimler ile korelasyonu değerlendirilmiştir. Çalışmanın amacı, ağılların ve yaylaların dağılışında topografik faktörlerin nasıl etkili olduğunu belirlemektir. Çalışma, fiziki faktörlerin ekonomik faaliyetler ve yerleşmeler üzerinde yarattığı olumlu ve olumsuz etkileri ortaya koymak bakımından önem taşımaktadır. Topografik faktörler kısa mesafelerde değiştiğinden ağıl ve yayla dağılışı da her yerde aynı değildir. Çalışma alanında 153 yayla ve 1055 ağıl tespit edilmiştir. Bunların belirli yükseltilerde yoğunlaşmasında su kaynakları ve biyoklimatik faktörler etkili olmuştur. Her eğim gurubunda yaylalara rastlanırken, ağılların yapımı için düz bir zemine ihtiyaç olduğundan 5º-10º eğimli yamaçlarda ağılların toplandığı gözlenir. Yaylalar, su kaynaklarının en fazla bulunduğu çalışma alanının batı tarafında toplanmışlardır. Ağıllar ise güneşlenme süresinden yararlanmak ve kötü hava şartlarından korunmak için güney tarafta toplanmışlardır.Distribution of “yayla”, which is a temporary settlement throughout Turkey, and sheep-barns have been investigated according to topographic factors (elevation, slope and exposure) around Hasandağı Mt and Melendiz Mt between Aksaray and Niğde Provices. Yayla and sheep-barns defined by GPS have been put into digitized 1:25000 topographic maps and the correlation between these settlements and topographic factors has been assessed. The aim of this study is to determine how the topographic factors affect the distribution of yayla and sheep-barns. The study is important in terms of the determination of positive and negative effects of physical factors on economical activities and temporary settlements. Since topographic factors change over short distances, distribution of these settlements is not the same everywhere. 153 plateaus and 1055 sheep-barns are recorded in the study area. The water springs and bioclimatic factors affect the density of these settlements at certain elevations. While yayla are encountered on each slope, sheep-barns are observed to exist on slopes between 5°-10° due to a need for a smooth place to build sheep-barn. Yayla is observed in the west part of the study area where water springs occur most. As for sheep-barns, to utilize sunbathe time and protect from bad weather conditions, they are gathered in the south

Changes and trends in total yearly precipitation of the Antalya district, Turkey

In this study, long term changes and trends in the annual rainfall of the Antalya Part, which is the region located in the western Mediterranean coast of Turkey containing many agricultural areas in its surrounding, were analysed. The aim of this study was to analyse the long term changes and trends in rainfall totals and present spatial distributions of annual and seasonal rainfall variability over the part. Rainfall data from 7 meteorological stations (Antalya, Alanya, Manavgat, Gazipasa, Finike, Korkuteli and Elmali) covering the years 1970-2011 were used in this study. Prepared rainfall variation maps clearly show that the highest annual variation is Antalya, while the lowest variation is Manavgat. According to the results obtained in trend analysis, in general, while a decreasing trend in winter rainfall is apparent, there is an apparent increasing trend in autumn rainfall. These results show a shift in seasons causing long-term droughts and potential infertile land to emerge. At some stations in the vicinity, there has been a prominent change from humid conditions to semi-arid conditions from beginning of 2000s. This study is expected to contribute to better understanding the effects of global climate change over precipitation in Antalya vicinity. (C) 2013 The Authors. Published by Elsevier Ltd

Changes and trends in precipitation and air temperature values during the period of 1970 and 2009 in the seyhan basin

Çalışmada Seyhan Havzası’nda ve yakın çevresinde bulunan 29 meteoroloji istasyonun 1970-2009 yıllarını kapsayan ortalama sıcaklık ve toplam yağış değerleri kullanılarak Erinç kuraklık indisi hesaplanmış ve iklim tipi belirlenmiş ve haritalandırılmıştır. Kayıtlı sıcaklık değerleri 1970-1992 ve 1993-2009 şeklinde iki döneme ayrılarak incelenmiştir. Yıllık ortalama sıcaklık, mevsimlik sıcaklık ve yıllık toplam yağış değerlerinin uzun süreli eğilimleri Mann-Kendall sıra ilişki katsayısı sınaması yöntemine göre analiz edilmiş ve eğilim oranları hesaplanmıştır. Çalışmaya konu olan meteoroloji istasyonlarının sıcaklık dizilerinde istatistiksel olarak anlamlı bir artış ve yağış dizilerinde anlamlı bir azalış tespit edilmiştir. Sıcaklıklardaki artış tüm mevsimlerde de görülmekle birlikte yaz sıcaklıklarındaki artış daha belirgin ve kuvvetlidir. Bunu sonbahar ve kış sıcaklıkları takip eder. Ayrıca yıllık toplam yağış miktarlarındaki azalış yönündeki eğilim kıyı ve orta bölümlerde kalan istasyonlarda daha belirgin iken kuzey bölümde kalan istasyonlarda (Suşehri, Zara ve Sivas) azalma belirsizdir. 1988’den sonra yağışlarda daha kurak koşullara doğru bir eğilim vardır. Yağış ve sıcaklık miktarlarındaki değişimler havzanın kuzeyinden güneyine doğru takip edildiğinde kuraklaşmanın orta ve güney bölümde daha fazla olduğunu ve su açığının ileriki yıllarda fazlaşacağını göstermektedir. 2. periyotta Pınarbaşı, Divriği, Kangal, Elbistan, Mut, Adana, Kozan, Karaisalı, Silifke, Göksun, Afşin ve Gemerek’de kuraklığa giden bir eğilim tespit edilmiştir. Ayrıca 2. periyotta Develi, Kayseri ve Şarkışla’da yarıkurak kurak iklim şartları yerini kurak iklim şartlarına bırakmıştır. Güneydeki Karataş, Mersin, Ceyhan, Kahramanmaraş, Anamur ve Yumurtalık’ta indis miktarında tespit edilen artış bu istasyonların şu an için kuraklık tehlikesi altında olmadığını göstermektedir.In this study, Erinç’s aridity index was calculated, the climate type of 29 meteorological stations was designated and mapped using the mean temperature and annual precipitation data of in the Seyhan Basin and its surrounding area covering the years 1970-2009. The recorded temperature data have been examined as the period (1970- 2009) was divided into two parts: 1970-1992 and 1993-2009. The long term trend of the annual mean temperature, seasonal mean temperature and total annual precipitation were analyzed using the Mann-Kendall rank correlation coefficient test and their trend ratio was also calculated. A statistical significant increase trend in the series of annual temperatures and significant decrease in the series of the annual precipitation 29 meteorological stations were determined. The increase in temperature is shown in whole seasons and the increase in the summer temperature is evident and strong. The autumn and the winter temperatures follow this temperature. Moreover, the decrease trend in total annual precipitation is more evident in the stations situated within the coast and the middle parts than stations situated within the north part (Suşehri, Zara and Sivas). After 1988, a general decreasing trend in precipitation was considerable severe. When changes of the precipitation and temperature accounts are followed from the north to the south of the basin, it is has been seen aridification is more in the middle and south parts and in these parts, water deficit will be more in later years. A trend towards drought was determined in Pınarbaşı, Divriği, Kangal, Elbistan, Mut, Adana, Kozan, Karaisalı, Silifke, Göksun, Afşin ve Gemerek during second period. In addition, arid condition took place of the semiarid condition in Develi, Kayseri and Şarkışla during this period. The increase in aridity index shows that Karataş, Mersin, Ceyhan, Kahramanmaraş, Anamur and Yumurtalık do not under the aridity hazard in the south part

Depositional Sequences of the Late Pleistocene Shoreline System, Bor Basin, Southern-Central Anatolia: Implications for Reconstructing Lake Level Changes

The Bor Basin is located in the east part of the Konya-Ereğli Plain occupied by Pleistocene lake (Fig. 1). Paleo-shoreline deposits rising western margins of the basin marked the former extent of a now desiccated Late Pleistocene Lake. This study evaluates the former lake level changes and the sequential evolution of a shoreline system that developed at the western margin with lacustrine fills of the Bor paleolake near Zengen settlement. The fills belongs to alluvial fans formed by streams coming from the high volcanic mountains located within the northern part of the basin. The sediment sequence of the fan reflects receded and extended levels of the former lake. 23 samples were obtained at the sand-quarry representing of various facies of the lacustrine fills. These samples were analyzed for mineralogical characterization, using XRD and their CaCO3 values were quantified. According to analysis, three evident different phases of weathering were distinguished in this deposit (Fig. 2). Weathering conditions occurred at the bottom of the profile (level 7) with the appearance of the vermiculite and illite/smectite mixed layer clays. Aridification phases occurred at the level of sample 16 with the appearance of the palygorskite. At the shallow levels from the samples 21 to 22, another aridification phase occurred attested by the appearance of the palygorskite, the mixed layers clays (illite/smectite) and the neoformation of the chlorite by weathering. The palygorskite occurrence showed only in the clay fraction (<2µm) associated with dolomite levels which support its secondary formation during dry periods and pedogenetic transformation. Pedogenesis conditions were attested also by the presence of the mixed layers clays at those levels