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Microclimatic variations in semi-arid ecosystems can cause topographic asymmetry over geologic time scales due to uneven distribution of incoming solar radiation as a function of slope aspect. This phenomenon has long been recognized in geomorphology and has been studied primarily in catchments with high spatial heterogeneity in climate forcing and underlying lithology. Due to fluctuations in prevailing climate and lithological differences in the studied catchments, the formation age and size of the catchments add another level of complexity and uncertainty. Due to their small size, uniform lithology, well-constrained initial morphology, and relatively young age, cinder cones are natural laboratories for better understanding the eco-hydro-geomorphic evolution caused by nonlinear interactions between vegetation, climate, and soil. The Sandal Divlit cinder cone located in the Kula volcanic field, western Turkey, is an inactive volcano and formed in the last stage of volcanism in the region. The climax vegetation in the primary succession following the volcanic eruption can be seen on north-facing slopes with trees. North-facing slopes have deeper soils than south-facing slopes, which have sparsely herbaceous plants and shrubs and thin, weakly developed soils. Airborne-LiDAR surveys and the digital elevation models having 5 m and 12.5 m spatial resolution were used to analyze the geomorphic descriptors and canopy structure of the cone as a function of aspect. In the summer and winter seasons, the surface temperatures of the cone were measured using a thermal-imaging drone. The results show that north-facing slopes are much cooler and have less evaporative demand than south-facing ones. As a result of denser vegetation attributed to relatively more available soil moisture, they are steeper than south-facing ones due to better erosion protection. Despite its young age (

The second-largest valley on Mars is Kasei Valles. This research focuses on the landforms produced by surface processes in the southern branch of Kasei Valles’s midstream. By using cross-cutting relationships, and empirical crater dating of landforms, we constructed a morpho-stratigraphical chronology of the valles. Landforms such as deeply eroded canyons, colluvial fans, landslides, topographic barriers, terraces, and trim lines are typical landforms that have been formed by surface processes.Our geomorphic mapping reveals that the valles were temporarily obstructed by two colluvial fans and a landslide, creating topographical obstacles to impound fluids (e.g lava, mudflow, water). The toe of the alluvial fans and the landslide were eroded by flights of terraces and trim lines, indicating a temporary, water-like liquid presence in the channel of the valles. The surface texture of the terrace surfaces indicates that the terrace staircases were probably created by a water-like fluid that stagnated and fluctuated for a while before the final evacuation.The chronology of these important events indicates that colluvial fans were deposited in two temporal clusters. The first colluvial fan generation was formed in the Early Amazonian period (1.74-1.14 Ga), and the second colluvial fan generation was formed in the Late-Middle Amazonian period (307 Ma). The landslide is significantly younger and is estimated to have formed 122 Ma ago. The floor of the valles’s channel is covered by platy-textured material, which was formed 90 Ma ago as lavas or mudflows, which is the youngest studied geomorphologic feature. The age of the landslide and valles’s floor help us to constrain the timing of erosional processes responsible for the flights of terraces and trimlines, which stretch along approximately 60 km from up to downstream. Accordingly, these features should be formed between 122 Ma and 90 Ma. We believe that the genesis of these features (terraces and trimlines) is associated with a Newtonian fluid (such as water) that ponded behind the colluvial fan dams and the climatic conditions that allow this fluid to stagnate over brief periods of time enough to form terraces and trimlines.

A devastating earthquake sequence occurred on February 6, 2023, within the East Anatolian fault system. Two main shocks, the Mw 7.7 Sofalaca-Şehitkamil-Gaziantep, and Mw 7.6 Ekinözü-Kahramanmaraş earthquakes occurred nine hours apart and affected 10 cities and more than an area of 100,000 km2 (PGA>0.08g). The earthquake-affected area mainly exhibits arid/semi-arid climatic conditions where approximately 15% of the landscape is characterized by steep topography (slope steepness>20°). Initial estimates of globally available predictive landslide models indicated extensive landslide distribution over the area.We examined high-resolution satellite images and aerial photos to provide a better insight into this co-seismic landslide event and its possible post-seismic consequences. These observations are going to be validated and enriched by detailed field surveys. This research presents our preliminary findings as a result of these investigations. Our observations carried out in the first two weeks after the sequence showed that rock fall and lateral spreading are the dominant landslide types, and the overall landslide population could be less than expected. Therefore, the resultant co-seismic landslide event seems unexpected, given the intensity of ground shaking and landscape characteristics. Based on the preliminary investigations, lithology, topographic relief, and climatic conditions appear to be the main variables causing these below expectations for landslide distribution. We should stress that our historical records mostly lack landslide events in arid/semi-arid conditions, as we observed in this event. In this context, this event is going to be recorded as one of a few of its kind. Our observations also showed intense ground shaking and strongly deformed numbers of hillslopes, although most have not failed yet. In particular, heavy rain and snowmelt may result in a considerable number of failures on those hillslopes that are prone to cracking and deformation due to strong ground shaking. In this respect, this area needs to be monitored for a long time to understand the earthquake legacy effect and post-seismic hillslope response.

– The archaeological structures buried underground are displayed by utilizing GPR. – Geomorphological units are determined via SVF and RRIM in the GIS environment. – The effects of dry farming, site-tethered pastoralism is discussed by using an ABM.

Wildfires have a long history in the Mediterranean and Atlantic coastal regions, and such devastating events are anticipated to increase in parallel with changing climatic conditions. Wildfires play an important role in short-term ecological and geomorphological changes, as they can instantly affect vegetation, soil properties, and drainage properties. In comparison to unburned conditions, wildfire alters the erosional response of hillslopes, increasing the potential for runoff and sediment flux, as reported in many studies. Specifically, wildfire-affected steep hillslopes can promote the initiation of debris flows which may cause substantial sediment delivery and increase hazard levels for society and infrastructure downstream of burned areas.In this study, we report the erosional response of hillslopes and spatial probability debris flows after the July 10, 2019, Dalaman, Göcek (Muğla) wildfire, which was effective in a total of 15 km2 forested area. We used different ground and remote sensing methods covering two years of field observation and measurements from shortly after the event. In our study, in which we compared the results obtained by conventional field-based assessments with Unmanned Aerial Vehicle (UAV) measurements, we quantified that the erosion is localized spatially in the middle and upper parts of the basins and led to an average erosion rate of more than 10 mm in two years. In addition, we revealed that the susceptibility of the debris flows after the fire has increased significantly, primarily concentrated in the far north of the fire-affected hillslope sections. We concluded that the spatial probability of debris-flow events and their runouts would increase their impacts by significantly affecting the excavation of hillslope materials, mainly boosted by salvage logging after the event. Moreover, our preliminary findings show that accurate estimates of the magnitude of post-wildfire debris flow and erosion potential are essential to comprehend immediate hazards as well as long-term geomorphic changes.This study has been produced benefiting from the 2232 International Fellowship for Outstanding Researchers Program of the Scientific and Technological Research Council of Turkey (TUBITAK) through grant 118C329. The financial support received from TUBITAK does not mean that the content of the publication is approved in a scientific sense by TUBITAK.

Landslides are one of the devastating geohazards that cause extensive socio-economic and environmental damages on local, regional, and global scales. Previous studies based on digital media sources have attracted attention to the high fatal landslide rate in Turkey, at a continental or global scale; however, the preparation of a comprehensive and long-term database for Turkey has been neglected until today. To examine this data gap, we present a new database of fatal landslide events resulting in fatalities from 1929 to 2019, which has been compiled using Turkish national and local printed and digital media reports, academic papers, disaster, and city annual reports. The fatal database of Turkey (FATALDOT) shows that, in total, 1343 people were killed in 389 fatal landslide events. The spatiotemporal distribution of the fatal landslides highlighted increasing trends with reference to two distinct hotspot zones throughout the Eastern Black Sea and Marmara Region, mostly around Istanbul megacity. Our results show that there has been a significant uniformity between the number of fatalities and fatal landslides triggered by anthropogenic and natural factors over the past decade, indicating an increasing dominance of human activities in fatality rates. Our findings also, for the first time, remarked the potential signatures of the economic crisis and political steadiness on fatal landslide trends. Nevertheless, we conclude that the increasing rate of anthropogenic disturbances in urban and mountainous areas, together with regional variances in topography and climatic setting, is essential in governing the pattern of fatal landslides.

In semi-arid ecosystems, microclimatic variations may lead to topographic asymmetry over geologic time scale due to uneven distribution of incoming solar radiation as a function of slope aspect. This phenomenon has long been recognized in geomorphology and mostly studied in catchments where may have a wide range of spatial heterogeneity in climate forcing and underlying lithology. The formation age and the size of the catchments add another level of complexity and uncertainty due to the fluctuations in prevailing climate and lithological differences in the studied catchments. However, cinder cones are natural laboratories to better understand the eco-hydro-geomorphic evolution resulted from the nonlinear interactions between vegetation, climate, and soil due to their small size, uniform lithology, well-constrained initial morphology, and relatively young age. The Sandal Divlit cinder cone located in the Kula volcanic field, western Turkey, is an inactive volcano and formed in the last stage of volcanism in the region. The climax vegetation in the primary succession following the volcanic eruption is observed on the north-facing slopes which host trees. The north-facing slopes have relatively deeper soils than south-facing slopes where host sparsely herbaceous plants and shrubs associated with thin and weakly developed soils. Airborne-LiDAR surveys and the digital elevation models having 5 m and 12.5 m spatial resolution were used to analyze the geomorphic descriptors and canopy structure of the cone as a function of aspect. The results show that north-facing slopes are steeper than south-facing ones due to better erosion protection as a result of denser vegetation. Despite its young age (This study has been produced benefiting from the 2232 International Fellowship for Outstanding Researchers Program of the Scientific and Technological Research Council of Turkey (TUBITAK) through grant 118C329. The financial support received from TUBITAK does not indicate that the content of the publication is approved in a scientific sense by TUBITAK.

The formation of badlands is commonly linked to the presence of dispersive deposits. Meanwhile, the sediments having more resistance to disintegration might also cause badlands formation given the time and adequate climate conditions. Although the notable influences of climate conditions have been highlighted on badlands morphologies so far, only a few attempts illustrated how materials weather in response to the diverse climate conditions. Supportingly, this research aims to learn about the primary weathering processes in various types of badland landforms (sharp-edged, rounded-edged, tower type, and calanchi mammellonari) in the Mediterranean arid, semi-arid, and humid climate of Turkey. For that purpose, we have used 11 badlands bedrock samples and determined climate conditions to simulate realistic weathering conditions in the laboratory condition. Bedrock samples were marl from the arid region, poorly sorted and packed sandstones from the Mediterranean region, highly consolidated sandstones from the humid region, pyroclastic sediments from the Cappadocia – semi-arid region. We have conducted four cycles representing each season during one water year to simulate precipitation and temperature variations. In this regard, we compiled the total amount and type of precipitation and insolation data for each season. Prior to the experiment, we have determined grain size, mineralogical composition, physico-chemical properties, the content of major elements of badland samples that enable us to discuss their morphological variety.Regarding the temperature conditions, we simulated day spring/autumn (~20°C), mild winter (4-5°C), winter (-2°C), summer (~25 – 35°C) conditions considering fluctuation of temperature along the different seasons. After precipitation in each cycle, represented by either rain or snow, we collected leachates to quantify the variations between the seasons by measuring volume, pH, electrical conductivity (EC), concentrations of anion, and cations.The laboratory experiments testing weathering processes under the different climate conditions and various types of badland materials show that the apparent differences in crust and desiccation crack emerged between the seasons. Although the obtained highest sediment flux in Mediterranean badlands having the deep crack systems, especially in autumn after high drying in summer, the ponds were formed relatively temporarily (a few hours) to long-lived (a few days) by filling the cracks with the sediments during spring seasons due to the scarcity in drying during the winter. The badland materials under arid climate conditions are highly likely to disintegrate because of their critical susceptibility to dispersivity; after one year of simulation (4th cycle), they became highly unstable due to their higher content of clay swelling capacity. However, the humid badland materials subjected to harsh climate conditions -snow and freezing conditions appeared to be the most durable samples reason for which is the strong cementation of coarse-grain sandstone. Seasonal trends in sample leachates' properties were also obtained. We can conclude that drying and wetting are more effective than the cooling and thawing processes in weathering of the bedrock from sampled badlands.This study has been produced benefiting from the 2232 International Fellowship for Outstanding Researchers Program of the Scientific and Technological Research Council of Turkey (TUBITAK) through grant 118C329.

Annually, a large number of landslide events that resulted in the deaths of dozens of people occur in Turkey. However, the preparation of an inventory of fatal landslide events in Turkey has been neglected until today. In this respect, a database on fatal landslide events in Turkey for the period from 1929 to 2019 was compiled from various sources comprising national and local printed and digital media reports with pre-determined keywords in Turkish, academic papers, disaster, and city annual reports, and government and aid agency reports. In the studied period, 389 landslides events that caused of death 1343 people were detected. According to the Mann-Kendall (MK) test and Sen's slope method, which is used to determine the temporal distribution characteristic of landslide events and deaths, an increasing trend is observed in both events and the number of deaths in the period comprising 1929-2019. These landslide events, which show intensity in the summer during the year, constitute two major density regions, the Eastern Black Sea Region and the Istanbul environment. In general, the Eastern Black Sea Region is represented by fatal landslides triggered by natural factors, while fatal landslides triggered by anthropogenic factors characterize the Istanbul and near vicinity. Spatially, fatal landslides were recorded in 227 different counties in 67 of 81 cities. The determination of the priority areas was evaluated by the population of the settlements exposed to the landslide and the probability value calculated with the number of landslides recorded and the relationship with the number of the dead. In conclusion, based on the final distribution pattern we revealed that the frequency of the landslides in provinces and districts where the topographic roughness is above the country average, at the Eastern Black Sea Region are strikingly high from the other hilly sections of the country.

We present the first detailed Quaternary landform map of the Büyük Menderes Graben System, located in western Turkey which is one of the most active extensional domains in the world. The main map was produced with a combination of TanDEM-X (12.5 m resolution), Red Relief Image Map, unmanned aerial vehicle, Google Earth images, and multiple fieldworks. The main map is presented at a scale of 1:160,000 although landforms were mapped at a scale of 1:15,000. The ten Quaternary landforms were defined considering their surface morphology and depositional environment. The alluvial fans, river terraces, and floodplains are the most common landforms. The spatial pattern of the alluvial fans and river terraces showed the variable rates of tectonics and surface processes along the strike of the graben system. The distribution of the meander cut-offs and paleo-shorelines imply that Büyük Menderes Graben System is vulnerable to geohazards like flash-flood sedimentation and flood events.

Badland areas are present in all continents, excluding Antarctica, and play a critical role in establishing local erosion and sedimentation rates. The presence of unconsolidated rocks (e.g., marls, sandstone, mudstone etc.) is a major driver controlling the distribution of badlands, which together with other environmental components, such as climate, tectonics, vegetation, and topography, determine their forms and processes. The mutual interaction of controlling factors in badlands areas provides a basis for developing a holistic approach to clarify their distribution patterns. Turkey's geodynamic evolution has led to the emergence of marine sedimentary rocks, pyroclastics, and continental clastics, especially in line with the uplift of the Anatolian Plateau and volcanism during the last 8 Ma.This study aims to explore the country-scale distribution of badlands and the controlling factors of this badland distribution in Turkey. Remarkably wide badlands landscapes (4494 km2) have been visually inspected using Google Earth ProTM to further digitize and extract geomorphological units by applying high-resolution multispectral images provided by WorldView-4/Maxar Technology and CNES/Airbus. To obtain exact boundaries, we eliminated contiguous flat areas surrounding the identified badlands by using red relief image map (RRIM) mosaics that express surface concavity and convexity combined with topographic slope derived from a digital elevation model of 5-m spatial resolution. Last, to determine the controlling factors of badlands distribution, we have compiled a global data set comprising 1-km resolution layers of mean annual precipitation, temperature and precipitation seasonality, aridity, NDVI, rainfall erosivity factor, elevation, and majority values of regional lithology in sub-catchments units. The enhanced investigation of the complex relationship that expresses the controlling factors of badlands distribution, has been conducted by K-means unsupervised cluster analysis.Our comprehensive regional analyses exploring the distribution and environmental attributes of major Turkish badlands identified five different groups or clusters of badlands that display spatial coherence with climatic and tectonic settings. We argue that Turkey's climatic and topographic transition zones, varying from Mediterranean climate dominated areas to the more arid Central Anatolian Plateau, and tectonically‑induced topographic barriers play a relevant role in discriminating these groups of badlands. Moreover, the Anatolian diversity of sedimentary rocks, which consists of Neogene and Paleogene continental clastics, volcano clastics & pyroclastics, and lacustrine deposits, makes an essential contribution to the identified, extensive badland distribution.This study has been produced benefiting from the 2232 International Fellowship for Outstanding Researchers Program of the Scientific and Technological Research Council of Turkey (TUBITAK) through grant 118C329. The financial support received from TUBITAK does not mean that the content of the publication is approved in a scientific sense by TUBITAK.

The main purpose of the study is to determine the general characteristics of the landslide sizes observed in Cretaceous and Eocene aged flysch assemblages at the Western Black Sea region of Turkey by using magnitude and frequency relations. For this purpose, the magnitude and frequency relations were investigated by considering power-law scaling characteristics of the geological formations. The probability distributions were also examined by considering Double Pareto and Inverse Gamma distribution models. According to the power-law relations, the rollover effects were observed at 0.047 and 0.048 km2, and the fractal dimensions of the distributions were obtained as −1.97 and −1.41 for Cretaceous and Eocene flysch assemblages, respectively. Considering the probability distributions, the best-fits were acquired from the models Double Pareto with three parameters estimated by maximum likelihood estimation for Cretaceous flysch and Kernel density estimation for Eocene flysch. When we compared these results with the results of a study carried out in the same flysch but in another sub-catchment, it is concluded that rollover effects and fractal dimensions may not be generalized, that means, the parameters may differ site to site depending on not only spatial resolution but also morphological, climatic, and anthropogenic features of the region in concern, and conversely, landslide size distributions fit Double Pareto distribution models in general.

Landslides are one of the destructive geomorphological hazards that cause substantial socio-economic and environmental damages on a global scale. Knowing the precise number of deaths caused by landslides and their spatial and temporal distributions will facilitate a better understanding of the losses and damages, and further to prevent and minimize the damages caused by this type of disasters. Thus, reliable historical inventories, including past landslide events, are crucial in understanding the future landslide hazards and risks.Turkey, similar to mountainous countries suffering from landslides, is also high-elevated (average altitude of >1100 m) and tectonically active country located where the Europe and Asia continents meet. In the years between 1995-2014, 335 of the total 1375 fatalities caused by landslides in European countries have occurred in Turkey. This reported number not only shows that Turkey is the first country in Europe in terms of deaths caused by landslides but also implies that the landslide related problems are overwhelming than expected in Turkey. Although many studies have been carried out on individual landslides and landslide inventories in Turkey, we have limited information about the landslides that cause death. However, there are many landslide events that resulted in the deaths of tens of people every year in Turkey. Therefore, neglecting fatal landslides and their consequences resulted in an unrealistic comprehension of landslide risk. In this respect, we contribute to filling this data gap by presenting the first country-scale archive inventory of fatal landslides, their spatio-temporal distribution, and the triggering mechanism characteristics for Turkey, which is Europe's topmost deadly country.The fatal landslide events in Turkey for the period from 1929 to 2019 were compiled from various sources comprising national and local printed and digital media reports with pre-determined keywords in Turkish, academic papers, disaster, and city annual reports, and government and aid agency reports. According to the new database, 1343 people lost their lives as a result of 389 landslide events in Turkey between 1929 and 2018. In total 197 fatal landslide events, which resulted in 301 deaths, were identified due to anthropogenic triggers (i.e., construction, infrastructure, and mining activities). On the other hand, 147 landslides occurred, and 883 people lost their lives due to natural triggering factors. The natural trigger origin of the fatal landslides is concentrated in the Eastern Black Sea and is generally shallow landslides corresponding to regolithic zones where chemical weathering is severe. On the contrary, the trigger factor of 45 landslide events cannot be assigned to the FATALDOT database due to a lack of detailed information in incidence reports. The database, which is planned to be transformed into an information system with a semi-automatic update feature, is thought to be an underlying data source for future research works to prevent hazard and risk studies and landslide-related deaths in the country scale.

This multidisciplinary project investigates the implications of aridification induced by climate change and human-induced land-cover land-use change in semiarid landscapes of Turkey on erosion dynamics and landscapes patterns and morphology. Deviations from climate mean states will result in loss of vegetation productivity and soil fertility in these water-limited ecosystems and exacerbate the natural conditions in terms of natural land‑cover and soil protection for natural resources sustainability. Here, we offer a comprehensive modelling framework to explore the water-soil-vegetation interactions under climate change for the following decades.Remotely‑sensed vegetation indices and maps will be used to identify the regions where are prone to land‑cover change under climate change. Hence, the climate projections for the 21st century taken from CMIP6 model experiments will be used for anticipating the potential changes in ecosystem dynamics and boundaries in these water-limited ecosystems. Moreover, these climate projections will be used as forcing data in a vegetation-coupled landscape evolution model to understand how the landscape morphology and erosion dynamics interact with changing climate in Turkish arid lands. Besides erosion dynamics, the future of the unique geomorphic landscape feature of these regions, the Turkish badlands, will be investigated based on climate projections.The outcomes of this project will enhance the comprehension of the effects of geomorphic, hydrological, and ecological processes on natural resources under climate change in semiarid Turkish landscapes.

Various mechanisms are proposed to explain landslide recovery time in the time following major earthquakes. However, research on prescribing possible recovery times following an earthquake is still relatively new. This paper provides an insight into factors governing landslide recovery time, which could be considered as a step forward in predictive modeling for landslide recovery time. To accomplish this, we examined 11 earthquake-affected areas based on the characteristics of both landslide events and landslide sites associated with diverse morphologic and climatic conditions. Our analyses indicate that the dominant characteristics of post-seismic landslide mechanisms determine the recovery time. The characteristics can be identified based on: (i) the fraction of area affected by landslides (%), (ii) mean relief and its standard deviation (m), (iii) average daily accumulated precipitation (mm) and (iv) rainfall seasonality index. If there are not enough co-seismic landslide deposits or not enough relief to trigger large deposits on hillslopes, then the recovery processes are mostly controlled by new landslides caused by a strength reduction of hillslope materials. In most of the cases, this brings a relatively quick recovery process in which the majority of post-seismic landslides may happen within a year or even in a month if sufficient intense rainfalls occur soon after the earthquake. If the predisposing factors create large co-seismic landslide deposits, then remobilization of material takes the role of the dominant mechanism and recovery may take years. Overall, our analyses show that the recovery takes relatively longer if a large amount of co-seismic landslide material is deposited within a high-relief mountainous environment where precipitation rate is low and not persistent.

Landslides are one of the geomorphological hazards that cause significant human, economic and natural losses worldwide and in Turkey as well. In general, landslides triggered by natural factors such as earthquakes, heavy rainfall and snow melting, or human activities cause a large number of casualties. Knowing the precise number of deaths caused by landslides and their spatial and temporal distributions will facilitate a better understanding of the losses and damages, and further to prevent and minimize the damages caused by this type of disasters. In this respect, reliable historical inventories, including past landslide events, are crucial in understanding the future landslide hazards and risks. In this study a new data set of landslides that caused loss of life in the 90-year period from 1929 and 2019 has been compiled, providing new insight into the impact of landslides for Turkey, which is Europe's topmost deadly country.The new archive inventory indicates that in the 90-year period a total of 1343 people lost their lives across the region in 389 landslide events in Turkey between 1929 and 2019. The distribution of the fatal landslides is highly varied and concentrated in two distinct zones along the Eastern Black Sea Region and Istanbul mega-city. Our analysis suggests that on a country scale the mapped factors that best explain the observed distribution are topographic relief and gradient, annual precipitation and population density. Temporal trend analysis reveals a significant rise in the number of deadly landslides and hotspots across the studied period was observed. The detailed analysis showed that the control factors of landslides caused by different triggering mechanisms (i.e., natural and anthropogenic) also vary. The landslides of natural trigger origin are concentrated in areas with high topographic relief and slope values, whereas those triggered by anthropogenic factors are concentrated in areas with low topographic relief and slope values. While the slope values were 10.5° in the areas where all the fatal landslides occurred, these values were 14.5° for natural landslides and 8° for anthropogenic landslides. In the areas where landslides triggered by natural factors, the average topographic relief is approximately 600 meters higher than the landslides of anthropogenic origin. Moreover, we observed that fatal landslides have not triggered during the seasonal rainy period, but rather caused by sudden and heavy torrential rainfall during the summer period when the average annual rainfall is low. Fatal landslides triggered by natural factors are concentrated in the Eastern Black Sea section and occur on the Upper Cretaceous and Lower-Middle Eocene volcanics classified as median volcanic rocks with an average thickness of ten meters. The landslides on these lithological units are shallow landslides, which occur mainly a few meters above the regolithic zone, where chemical weathering is severe in this area. Fatal landslides of anthropogenic origin occur in urban and metropolitan centers where human activity is high due to infrastructure and construction works, and they are predominantly corresponding with areas where the topographic relief difference is low.

High Anatolian orographic margins have large variations in terms of topographic relief, precipitation, and uplift rate. These variations lead to the dynamics of mass movements and surface runoff, which are the dominant geomorphological processes in ice-free mountain landscapes. There is growing recognition that large landslides are important agents of landscape evolution, resulting in massive slope failures, which can cause extensive and rapid topographic changes in many active orogenic belts. Unlike the cognatic orogenic plateau margins in the world, there are no studies available on the large landslides and their geomorphic impact at the margins of the Anatolian Plateau. This study presents results from a regional-scale inventory of 1290 large landslides (> 1 km2) that allow the characterization of spatial distribution and landslide-dominated landscapes in the northern margins of the Anatolian Plateau. The majority of large landslides are clustered in three main zones that correspond to the Western, Central, and Eastern Pontides, which is an east-west-trending orogenic belt that represents a coalesced tectonic entity in the northern section of Turkey. Nearly 80% of large landslides have occurred in a terrain with a mean hillslope relief of > 1000 m in those three landslide-dominated landscapes. The results of regional comparisons reveal that in addition to hillslope relief and steepness, lithotectonic differences largely control the abundance of landslides along the northern margins of the Anatolian Plateau. In this respect, the spatial distribution and abundance of large landslides imply a landscape in which lithological and tectonic controls on hillslope erosion are more significant than climate. The study further shows that the parallel or perpendicular position of the landslides with respect to the direction of the drainage network is effective as positive or negative feedback in response to fluvial dissection of the plateau margins. On the other hand, there is certainly a need for more comprehensive radiometric dating studies to understand the contribution of large landslides on the erosional decay rate of Anatolian Plateau margins. Furthermore, the presence of these large landslides and the derived deposits in this dynamic terrain provide a unique opportunity for deciphering the past climatic and seismic events.

Kelkit Çayı Vadisi heyelan yoğunluğu bakımından Türkiye ortalamasının üzerindedir. Bu vadi yamaçlarının üst kesimlerinde yapısal düzlüklerin bulunduğu alanlarda kış aylarında biriken kar ilkbahar aylarında aniden erimektedir. Eriyen kar, bu düzlüklerin önündeki eğimli yamaçlarda su çıkışlarına neden olmakta ve büyük katastrofik heyelanları tetiklemektedir. Gözlem ve literatür araştırmaları sonucunda bu tetiklenmenin kış aylarında vadideki bazı yamaçlarda karın uzun süre tutunması, ilkbaharda güneş radyasyonuna bağlı eridikten sonra sızması ve akışa geçmesiyle gerçekleştiği tespit edilmiştir. Bu etkinin yüksek olduğu yamaçlarda heyelan hassasiyetinin de yüksek olduğu bilinmektedir. Tetikleyici faktör bakımından yamaç hassasiyetini belirlemek çalışmanın amacını oluşturmaktadır. Bu amaçla çalışma alanı 3600 fiziki yamaç ünitesine bölümlenmiştir. Bu ünitelerin tutunma, sızma ve akış hassasiyetini belirlemek için, uzman görüşütarafından etken faktörler ve etki derecelerinin belirlendiği M-AHP yöntemi kullanılmıştır. Tutunma modeli için çok çözünürlüklü vadi taban düzlüğü indeksi, yükselti ve bakı, sızma modeli için solar radyasyon, Topoğrafik Nemlilik İndeksi (TNİ) ve Hidrolojik Toprak Grubu (HTG), akış modeli için ise eğim, rölyef ve HTG parametreleri kullanılmıştır. Tutunma, sızma ve akış için en yüksek kararın alındığı yamaç üniteleri belirlenerek ana tetikleyici kar erimelerinin mekânsal hassasiyet üzerinde etkisi ortaya konulmuştur. Elde edilen sonuçlarda birden fazla modelin çıktısının en yüksek (örn. tutunma-sızma-akış) değerini taşıyan yamaçlarda mekânsal hassasiyetin daha yüksek olduğu tespit edilmiştir. Bu yamaçların özellikle kuzey blokta heyelanların başlangıç bölgelerine karşılık geldiği ortaya çıkmıştır. Heyelana elverişli zemini hazırlayan “tutunma-sızma” yamaçlarının ise eski heyelan içlerine, “sızma-akış” yamaçlarının ise özellikle kuzey yamaçlar olmak üzere heyelanların transfer zonlarına karşılık geldiği tespit edilmiştir. Kuzey yamaçlarda sızmanın yüksek olmasından kaynaklı su içeriğinin fazla olması bu yamaçlarda heyelanın tektiklenmesine neden olmaktadır. Bunun dışında çalışma alanının güney bloğunda ise “tutunma-akış”ın etkin olduğu yamaçlar bulunmaktadır., Kelkit Valley has landslide density higher than the Turkey average. Accumulated snow in winter rapidly melt at the spring months and it cause water outlets on high slopes in front of these plateau and this triggers large catastrophic landslides. As a result of observation and literature investigations, it has been determined snow stay on the ground for a long term, after melt in the spring due to solar radiation it being infiltration and finally it passing flow all of which triggers landslide. It is known that landslide sensitivity is high on slopes where this effect is high. The purpose of this study is determine slope sensitivity in terms of trigger factor. For this purpose, the study area is physically divided into 3600 slope units. The M-AHP method was used to for determine the snow adhesion, infiltration, and flow sensitivity of these units, including the factors and the impact levels on this sensitivity via the expert opinion. Multi Resolution Valley Bottom Flatness, altitude and aspect parameters were used for snow adhesion. Topographic Wetness Index (TWI), Hydrologic Soil Group (HSG) and solar radiation parameters were used for the infiltration. Altitude, slope and Hydrologic Soil Group (HSG) parameters were used for the flow. The slope units that the highest decision is determine was made for adhesion, infiltration and flow were determined the spatial sensitivity based on main triggering snowmelt. In the results obtained, it was found that the spatial sensitivity is higher in the slopes having the highest value of the output of more than one model (e.g., snow adhesion-infiltration-flow). It was determined these slopes especially correspond to the starting regions of the northern block landslides. It has been found that the adhesion-infiltration slopes, which prepare convenient ground, correspond to the old-landslide, and infiltration-flow slopes correspond to the transfer zones of the landslides especially the northern block. Due to the high infiltration on the northern slopes, the water content be high and the landslide is triggered on these slopes. Apart from this, the adhesion-flow slopes effect in the southern block of the study area more.

In this study, the high-resolution palynological data derived from two cores taken from Mogan Lake in the Golbasi Basin of the Ankara region in central Anatolia (Turkey) are presented. The results provide the palaeobotanical, palaeoclimatological and palaeoenvironmental records of the last ca. 3100 years for the region which is characterised by rich natural resources and a long human occupation history. The major climatic events and the archaeological-historical periods, which are well established in previous works, along with textual sources, are related to vegetation history inferred from the palynological investigation in the study area. Five main vegetation phases are distinguished and interpreted. Our findings demonstrate that the phases of limited woody vegetation cover are chiefly coupled to several dry climate periods, with some exceptions. Steppe vegetation in an open landscape accompanied by more cultural indicators and lesser arboreal elements is inferred during the Near-East Aridification Phase at the LBA-Iron Age transition (c. 1200-850 BCE), Roman Warm Period before 700 CE, Medieval Warm Period at about 1020 CE, the 1500s and twentieth century. Only during the three dry episodes in the 1600s, 1800s and at the start of Modern Warming Period (in the twentieth century) partial arboreal recovery is deduced, and land-cover patterns are related to both natural and human-induced factors. The most extensive pine-dominated forest cover coincides mainly with the three wet climatic episodes, in Galatians times of the Hellenistic Period at c. 2080 BP, the 700s CE of the middle Byzantine era, the Seljuqs Dynasty and the earlier Ottoman Periods (c. 1165-1432/1435 CE). The former episode is represented by remarkable signs of human interference, while the others have marks of sporadically less cultivated landscape. It is concluded that a combination of various factors can be taken into account as the drivers of vegetation changes in the Ankara region, but climate appears to have been the primary agent in shaping the land-cover. (C) 2021 Elsevier Ltd. All rights reserved.

The Sinop Peninsula is located at the northernmost part of the Asia Minor (Anatolia). Its geographic position between the Central Pontide Mountains and the Black Sea together with the presence of young geological units and landforms provides favorable conditions for understanding onshore and offshore geological and geomorphic processes acting along the northern Anatolian coasts. Here, we focus on some landscapes that constitute one of the best examples along the Turkish Black Sea coast. These are inundated fluvial valleys, uplifted isthmus and marine terraces, and paleo- and active dunes.

We present a new, seismologically consistent expression for the total area and volume of populations of earthquake-triggered landslides. This model builds on a set of scaling relationships between key parameters, such as landslide spatial density, seismic ground acceleration, fault length, earthquake source depth, and seismic moment. To assess the model we have assembled and normalized a catalog of landslide inventories for 40 shallow, continental earthquakes. Low landscape steepness causes systematic overprediction of the total area and volume of landslides. When this effect is accounted for, the model predicts the total landslide volume of 63% of 40 cases to within a factor 2 of the volume estimated from observations (R2=0.76). The prediction of total landslide area is also sensitive to the landscape steepness, but less so than the total volume, and it appears to be sensitive to controls on the landslide size-frequency distribution, and possibly the shaking duration. Some outliers are likely associated with exceptionally strong rock mass in the epicentral area, while others may be related to seismic source complexities ignored by the model. However, the close match between prediction and estimate for about two thirds of cases in our database suggests that rock mass strength is similar in many cases and that our simple seismic model is often adequate, despite the variety of lithologies and tectonic settings covered. This makes our expression suitable for integration into landscape evolution models and application to the anticipation or rapid assessment of secondary hazards associated with earthquakes.

Morphological changes, caused by the erosion and deposition processes due to water discharge and sediment flux occur, in the banks along the river channels and in the estuaries. Flow rate is one of the most important factors that can change river morphology. The geometric shapes of the meanders and the river flow parameters are crucial components in the areas where erosion or deposition occurs in the meandering rivers. Extreme precipitation triggers erosion on the slopes, which causes significant morphological changes in large areas during and after the event. The flow and sediment amount observed in a river basin with extreme precipitation increases and exceeds the long-term average value. Hereby, erosion severity can be determined by performing spatial analyses on remotely sensed imagery acquired before and after an extreme precipitation event. Changes of erosion and deposition along the river channels and overspill channels can be examined by comparing multi-temporal Unmanned Aerial Vehicle (UAV) based Digital Surface Model (DSM) data. In this study, morphological changes in the Büyük Menderes River located in the western Turkey, were monitored with pre-flood (June 2018), during flood (January 2019), and post-flood (September 2019) UAV surveys, and the spatial and volumetric changes of eroded/deposited sediment were quantified. For this purpose, the DSAS (Digital Shoreline Analysis System) method and the DEM of Difference (DoD) method were used to determine the changes on the riverbank and to compare the periodic volumetric morphological changes. Hereby, Structure from Motion (SfM) photogrammetry technique was exploited to a low-cost UAV derived imagery to achieve riverbank, areal and volumetric changes following the extreme rainfall events extracted from the time series of Tropical Rainfall Measuring Mission (TRMM) satellite data. The change analyses were performed to figure out the periodic morphodynamic variations and the impact of the flood on the selected meandering structures. In conclusion, although the river water level increased by 0.4–5.9 meters with the flood occurred in January 2019, the sediment deposition areas reformed after the flood event, as the water level decreased. Two-year monitoring revealed that the sinuosity index (SI) values changed during the flood approached the pre-flood values over time. Moreover, it was observed that the amount of the deposited sediments in September 2019 approached that of June 2018.

Predictive mapping of susceptibility to earthquake-triggered landslides (ETLs) commonly uses distance to fault as spatial predictor, regardless of style-of-faulting. Here, we examined the hypothesis that the spatial pattern of ETLs is influenced by style-of-faulting based on distance distribution analysis and Fry analysis. The Yingxiu–Beichuan fault (YBF) in China and a huge number of landslides that ruptured and occurred, respectively, during the 2008 Wenchuan earthquake permitted this study because the style-of-faulting along the YBF varied from its southern to northern parts (i.e. mainly thrust-slip in the southern part, oblique-slip in the central part and mainly strike-slip in the northern part). On the YBF hanging-wall, ETLs at 4.4–4.7 and 10.3–11.5 km from the YBF are likely associated with strike- and thrust-slips, respectively. On the southern and central parts of the hanging-wall, ETLs at 7.5–8 km from the YBF are likely associated with oblique-slips. These findings indicate that the spatial pattern of ETLs is influenced by style-of-faulting. Based on knowledge about the style-of-faulting and by using evidential belief functions to create a predictor map based on proximity to faults, we obtained higher landslide prediction accuracy than by using unclassified faults. When distance from unclassified parts of the YBF is used as predictor, the prediction accuracy is 80 %; when distance from parts of the YBF, classified according to style-of-faulting, is used as predictor, the prediction accuracy is 93 %. Therefore, mapping and classification of faults and proper spatial representation of fault control on occurrence of ETLs are important in predictive mapping of susceptibility to ETLs.

In this study we develop an empirical method to estimate the volume threshold for predicting coseismic landslide dam formation using landscape parameters obtained from digital elevation models (DEMs). We hypothesize that the potential runout and volume of landslides, together with river features, determine the likelihood of the formation of a landslide dam. To develop this method, a database was created by randomly selecting 140 damming and 200 non-damming landslides from 501 landslide dams and > 60 000 landslides induced by the Mw 7.9 2008 Wenchuan earthquake in China. We used this database to parameterize empirical runout models by stepwise multivariate regression. We find that factors controlling landslide runout are landslide initiation volume, landslide type, internal relief (H) and the H/L ratio (between H and landslide horizontal distance to river, L). In order to obtain a first volume threshold for a landslide to reach a river, the runout regression equations were converted into inverse volume equations by taking the runout to be the distance to river. A second volume threshold above which a landslide is predicted to block a river was determined by the correlation between river width and landslide volume of the known damming landslides. The larger of these two thresholds was taken as the final damming threshold. This method was applied to several landslide types over a fine geographic grid of assumed initiation points in a selected catchment. The overall prediction accuracy was 97.4% and 86.0% for non-damming and damming landslides, respectively. The model was further tested by predicting the damming landslides over the whole region, with promising results. We conclude that our method is robust and reliable for the Wenchuan event. In combination with pre-event landslide susceptibility and frequency–size assessments, it can be used to predict likely damming locations of future coseismic landslides, thereby helping to plan emergency response. Copyright © 2014 John Wiley & Sons, Ltd.

The Black Sea Region of Turkey is one of the most landslide prone areas due to its high slope topography, heavy rainfall, and highly weathered hillslope material conditions. Preparation of landslide inventory maps is the first step in producing landslide susceptibility maps. Ground-based methods for mapping landslide occurrences are time-consuming and expensive. Additionally, landslide mapping based on satellite imageries and aerial photographs has some limitations, including climatic conditions, cost, and limited repetitive measurement capacity. Visual interpretation-based landslide mapping, which is based on satellite imageries and aerial photographs, is a time-consuming procedure that requires an experience-based expert opinion. Therefore, the data acquisition based on unmanned aerial vehicle (UAV) and landslide event inventory maps using an object-based classification approach can be superior to other methods in terms of speed and cost. In this study, we developed a semiautomatic model using object-based image analyses for rapid mapping of shallow landslides from the data obtained from UAVs after major landslide events in the Black Sea Region of Turkey. For this purpose, two test sites—Kurucasile (Bartin) and Cayeli (Rize)—were selected. Landslide mapping models were developed in the investigation sites, and the performance of the models was evaluated. The landslides' data obtained with the developed models were compared to the landslides' data produced by the experts. The comparison process revealed that landslides mapped by using UAV data have an accuracy rate higher than 86% according to the number of landslides and 83% according to the landslide area.

A precise, accurate and complete landslide inventory is indispensable for the establishment of reliable landslide susceptibility and hazard maps. In the preparation of landslide inventories, dense vegetation cover is the major obstacle that confounds the topographic signature of landslides. Today, the growing usage of light detection and ranging (LiDAR) technology in the field of geoscience illuminates the mystery of the landscapes cloaked in dense vegetation by providing a new visual acuity to researchers. Turkey, similar to many mid-latitude mountainous countries suffering from landslides, is still continuing landslide inventory mapping with conventional methods such as aerial photo interpretations (API), although 68% of landslide events occurred under dense forest cover in the north of the country. Despite the country-wide medium-scaled landslide catalogs, the number and the abundance of landslides covered by forests remain largely unknown regardless of the increasing availability of high-resolution remote-sensing data. From these motivating insights and drawbacks, the study's focus is to evaluate the capability of mapping landslides by visually analyzing airborne LiDAR DTM derivatives and compare the results with the 1:25,000 scaled API-based inventory to understand the potential contribution of LiDAR technology in Europe's deadliest country (Turkey) in terms of landslides. The landslide mapping results for a test area located in the densely forested Ulus Basin, Western Black Sea region, reveal that the extent and the number of the mapped landslides (n = 902) from the airborne LiDAR data are much higher than those of the available API-based landslide inventory, which includes 67 landslides. Comparative analysis on topographic signatures of landslides is also underpinned on a distinct discrepancy of slope failure diagnostic indicators captured by the two available DEMs derived from LiDAR and 1:25,000 scaled topographic maps, emphasizing the success rate of LiDAR-derived DEM in recognition and mapping landslides with higher precision and accuracy. Together with all analysis results, the landslide recognizability degree assessment based on the forest cover percentage and slope height differences of landslides highlights that the LiDAR data enable landslides to be defined up to 100 m2, while this value is 20 times lower than that of estimated values from API-based landslides. In addition to underlining the contribution of LiDAR technology to the recognition of landslides hidden under dense vegetation, these findings stress the importance of LiDAR data on complete and accurate landslide inventories for production of reliable susceptibility and hazard maps and further a better understanding of the landslide processes and reducing related losses.

Kelkit Çayı, Kuzey Anadolu Fayı tarafından kontrol edilen son derece çizgisel bir vadi şekline sahiptir. Litolojik geçişlerin keskin, topoğrafik rölyef ve eğimin yüksek olduğu bir sahadır. Çalışma alanını oluşturan Kelkit Çayı’nın aşağı çığırı (Umurca-Koyulhisar arası) tektonik ve jeomorfolojik süreçlere bağlı gelişen heyelanların yoğun olduğu bir bölgedir. Çalışmanın amacı heyelan tehlikesinin yüksek olduğu bu alanda heyelanların jeolojik ve jeomorfolojik koşullara bağlı dağılım karakteristiğini ortaya koymaktır. Bu doğrultuda yüksek çözünürlüklü (SPOT, WorldView) uydu görüntülerinden oluşturulan heyelan envanterinin doğruluk kontrolleri arazi çalışmaları ile sağlanmıştır. Çalışma alanında 0.004-23.2 km2 arasında değişen 433 heyelan belirlenmiştir. Bu heyelanlar; akma, düşme, kayma tipinde olmak üzere üç ana sınıf altında haritalanmıştır. Heyelan tiplerinin eğim, rölyef, yükselti değer aralıklarında farklı dağılım gösterdikleri, litolojik olarak ise heyelanların Eosen volkanik çökel kayalarda ve Maestrihtiyen kireçtaşlarında yoğunlaştığı tespit edilmiştir. Özellikle birçoğunun kaya düşmeleri olduğu küçük heyelanların faya yakın zonlarda meydana geldiği tespit edilmiştir. Çalışmada haritalanan heyelanların belirli bir topoğrafik eğim ve rölyef değerleri arasında dağıldıkları ve jeomorfolojik açıdan geliştikleri alanların rastlantısal olmadığı, üst kesimlerde daha düze yakın plato aklanında ve paleo-heyelan topoğrafyaları içerisinde biriken karların ani erimesinin bu sürecin heyelanların tetiklenmesindeki ana neden olduğu ortaya konmuştur., Kelkit Creek is a highly linear valley controlled by North Anatolian Fault. The region has high topographical relief and slopes with sharp lithological transitions. Landslides due to tectonic and geomorphological processes are common in the downstream part of Kelkit Creek (between Umurca-Koyulhisar), which is the study area. The aim of the study is to reveal the distribution characteristics of the landslides driven by geological and geomorphological conditions in this highly landslides prone region. For this purpose, the accuracy of the landslides inventory obtained from high-resolution satellite images (SPOT, WorldView) was verified via field studies. In the study area, 433 landslides with sizes ranging 0.004-23.2 km2 and types of flow, fall and slides were mapped. It was detected that the distribution of the landslides was different for different slope, relief and elevation ranges. Also, we found out that the landslides were concentrated in Eocene aged sedimentary rocks and Maastrichtian aged limestones. Moreover, we detected that small-sized landslides (especially rock-falls) occurred in zones nearby the fault line. According to the study it was revealed that the distribution of the mapped landslides in the study area was not arbitrary and they were found to be concentrated in certain slope and relief ranges. Finally it was found that the sudden melting of the accumulated snow in the higher altitude plateau catchments and in the paleo-landslide topographies was the main triggering factor for the formation of landslides.

23 Ekim 2011 Van Depremi (Mw 7.1) ~2480 km2’lik bir alanda 70’in üzerinde heyelan tetiklemiştir. Bu heyelanları genel olarak düşme kayma ve yanal yayılma türü heyelanlar oluşturmaktadır. Heyelanların küçük bir kısmı yapıları ve ulaşım ağını doğrudan etkilemiştir. Bu heyelanlar içerisinde en ciddi ve kalıcı hasara neden olan Erçiş ilçesi, Çelebibağ Mahallesi’ndeki yanal yayılmalardır. Çalışmada yenilmelerin jeomorfolojik ve jeolojik karakteristiklerine bağlı olarak beş farklı ortamda yoğunlaştığı ortaya koyulmuştur. Bu alanlar: (1) eğim değerlerinin ortalamasının yüksek olduğu (32°) dağlık ve engebeli alanlar, (2) orta derecede eğimli (14°-18°) yıkanma yamaçları, (3) Kuvaterner alüvyonlarının egemen olduğu ve düşük yükselti farklarına sahip vadi ve ova tabanları, (4) eğim değerleri yüksek (15°- 40°) dik kıyı kuşağı ve (5) eski heyelan kütlelerinin yan yamaçlarıdır. Çalışmada heyelanların %98’inin deprem kaynak fayının tavan bloğunda oluştuğu tespit edilmiştir. Sismik faktörlerin yanı sıra topoğrafik ve litolojik koşulların heyelan oluşum ve mekansal dağılımı üzerinde birinci derecede rol oynadığı tespit edilmiştir. Dünyada gerçekleşmiş benzer faylanma mekanizması ve büyüklükteki depremlerle kıyaslandığında Van depreminin beklenenden daha az heyelan tetiklediği gözlenmiştir. Bu bakımdan heyelan sayısının ve heyelandan etkilenen alanın düşük olmasının temel nedeninin tavan bloğun (hanging-wall) ortalama eğim ve topoğrafik röliyef değerlerinin küresel eşlenik depremlere göre daha düşük olmasından kaynaklandığı sonucuna varılmıştır., October 23, 2011 Van earthquake (Mw 7.1) triggered more than 70 landslides, over an area of ~2480 km2. These landslides were mainly consisted of falls and slides, although lateral spreadings also occurred. Among these landslides, a small portion directly affected the structures and the transportation network. The most important permanent damage that was caused by these landslides was a lateral spreading which occurred in the Çelebibağ district in the Erciş County. In the study, it has been found out that the failures were geographically concentrated, which were associated with five characteristic geomorphic and geologic settings. These areas correspond to: (1) mountainous and hilly terrains with high average slope (32°), (2) modarately steep wash slopes (14°-18°), (3) plains and valley floors with low elevation differences and where Quaternary alluvials dominated, (4) the coastal belt with high steep slopes (15°- 40°), (5) flanks of the old landslides. The study revealed that 98% of the landslides were located on the hanging-wall of the earthquake source fault. It has been determined that in addition to the seismic factors, the topographical and lithological conditions played a vital role on the occurrence and spatial distribution of landslides. I observed that Van earthquake has triggered fewer landslides than expected compared to the earthquakes of similar magnitude and faulting mechanism from the world. In this respect, I conclude that the less number of landslides and the total area affected by landslides can be explained with the lower value of average hillslope gradient and topographic relief of the hanging-wall block with respect to the global equivalent earthquakes.

Earthquake-triggered landslide dams are potentially dangerous disrupters of water and sediment flux in mountain rivers, and capable of releasing catastrophic outburst flows to downstream areas. We analyze an inventory of 828 landslide dams in the Longmen Shan mountains, China, triggered by the M-w 7.9 2008 Wenchuan earthquake. This database is unique in that it is the largest of its kind attributable to a single regional-scale triggering event: 501 of the spatially clustered landslides fully blocked rivers, while the remainder only partially obstructed or diverted channels in steep watersheds of the hanging wall of the Yingxiu-Beichuan Fault Zone. The size distributions of the earthquake-triggered landslides, landslide dams, and associated lakes (a) can be modeled by an inverse gamma distribution; (b) show that moderate-size slope failures caused the majority of blockages; and (c) allow a detailed assessment of seismically induced river-blockage effects on regional water and sediment storage. Monte Carlo simulations based on volumetric scaling relationships for soil and bedrock failures respectively indicate that 14% (18%) of the estimated total coseismic landslide volume of 6.4 (14.6) x 10(9) m(3) was contained in landslide dams, representing only 1.4% of the >60,000 slope failures attributed to the earthquake. These dams have created storage capacity of similar to 0.6x 10(9) m(3) for incoming water and sediment. About 25% of the dams containing 2% of the total river-blocking debris volume failed one week after the earthquake; these figures had risen to 60% (similar to 20%), and >90% (>90%) within one month, and one:year, respectively, thus also emptying similar to 92% of the total potential water and sediment storage behind these, dams within one year following the earthquake. Currently only similar to 0.08 x 10(9) m(3) remain available as natural reservoirs for storing water and sediment, while similar to 0.19 x 10(9) m(3), i.e. about a third of the total river-blocking debris volume, has been eroded by rivers. Dam volume and upstream catchment area control to first order the longevity of the barriers, and bivariate domain plots are consistent with the observation that most earthquake-triggered landslide dams were ephemeral. We conclude that the river-blocking portion of coseismic slope failures disproportionately modulates the post-seismic sediment flux in the Longmen Shan on annual to decadal timescales.

Projected scenarios of climate change involve general predictions about the likely changes to the magnitude and frequency of landslides, particularly as a consequence of altered precipitation and temperature regimes. Whether such landslide response to contemporary or past climate change may be captured in differing scaling statistics of landslide size distributions and the erosion rates derived thereof remains debated. We test this notion with simple Monte Carlo and bootstrap simulations of statistical models commonly used to characterize empirical landslide size distributions. Our results show that significant changes to total volumes contained in such inventories may be masked by statistically indistinguishable scaling parameters, critically depending on, among others, the size of the largest of landslides recorded. Conversely, comparable model parameter values may obscure significant, i.e. more than twofold, changes to landslide occurrence, and thus inferred rates of hillslope denudation and sediment delivery to drainage networks. A time series of some of Earth's largest mass movements reveals clustering near and partly before the last glacial-interglacial transition and a distinct step-over from white noise to temporal clustering around this period. However, elucidating whether this is a distinct signal of first-order climate-change impact on slope stability or simply coincides with a transition from short-term statistical noise to long-term steady-state conditions remains an important research challenge. Copyright © 2011 John Wiley & Sons, Ltd.

This paper presents the preliminary results of an extensive study of the mapping the distribution of landslides triggered by the Wenchuan earthquake in Sichuan Province, China, on 12 May 2008. An extensive landslide interpretation was carried out using a large set of optical high resolution satellite images (e.g. ASTER, ALOS, Cartosat-1, SPOT-5 and IKONOS) as well as air photos for both the pre- and post-earthquake situation. Landslide scarps were mapped as points using multi-temporal visual image interpretation taking into account shape, tone, texture, pattern, elevation and ridge and valley orientation. Nearly 60,000 individual landslide scarps were mapped. The landslide distribution map was compared with the inventory map that was prepared directly after the earthquake, which contains about 11,000 individual landslide points, through the calculation of normalized landslide isopleths maps. Remarkable differences were observed, as the earlier inventory mapping did not consider the pre-earthquake situation and did not consider all individual landslides. As part of the landslide inventory, landslides were identified that had blocked the drainage and had formed landslide dams. The landslide distribution was compared with a number of aspects, such as the seismic parameters (distance to epicenter, distance to fault rupture, co-seismic fault geometry and co-seismic slip distribution), and geology. The most remarkable correlation found was with the co-seismic slip distribution and the fault geometry. Landslide distribution in the section of the fault that had mainly a thrust component with low angle fault plane was found to be much higher than the sections that had steeper fault angles and a major strike slip component.

Seismic and multi-beam bathymetric data from the northern shelf and slope of the Cinarcik Basin, which is generated by the North Anatolian Fault Zone (NAFZ) located in the easternmost basin in the Marmara Sea, were re-interpreted to better understand the future sub-marine landslide susceptibility. Seismic data indicate that upper surface of the sub-marine extension of the Paleozoic rocks has an NNE–SSW oriented basin and a ridge type morphology controlled by the secondary faults of the NAFZ. Basins are fulfilled by Plio-Quaternary sediments, which are cut by strike-slip faults on the shelf and slope. The thickness of basin deposits reaches up to 130 m toward the linear northern slope of the Cinarcik Basin. A relatively recent sub-marine landslide, the Tuzla Landslide, cuts the slope of the Cinarcik Basin. The detailed morphological investigation indicates that the Tuzla Landslide is a deep-seated rotational landslide, which was likely triggered by activity of the NAFZ. Morphological analyses also indicate that the thick Plio-Quaternary deposits on the Paleozoic basement slid during the Tuzla Landslide event. This landslide is considered as a key event to understand the dynamics of the potential landslides on the northern shelf and slope of the Cinarcik Basin. Two areas locating on the eastern and the western sides of the Tuzla Landslide are considered as the potential areas for future sliding due to similarities of geological and geomorphological features with the Tuzla Landslide such as similar thick Plio-Quaternary deposits, similar slope morphology, and similar fault activity cutting the sediments. Considering this information, the purposes of the present study are to determine the dynamics of the possible landslide areas and to discuss their effects on the sub-marine morphology. In the light of the interpretations, the amounts of possible displaced material are obtained. Three different landslide scenarios due to possible slide surfaces for future landslides are developed and assessed. The first scenario is sliding of the sediments at the shelf break. The third scenario is a mass movement of almost whole basin deposits on the Paleozoic rocks. The latter one is evaluated as less important because of the volume of the displaced material, and the latter one is accepted as lowest possible event. Among the scenarios, the second scenario is accepted as the most critical and possible because of the amount of the slipped material and existence of faults rupture, which is considered as further sliding surfaces. These landslides will result in important changes in shelf, slope and basin floor in the study area.

In the international literature, although considerable amount of publications on the landslide susceptibility mapping exist, geomorphology as a conditioning factor is still used in limited number of studies. Considering this factor, the purpose of this article paper is to implement the geomorphologic parameters derived by reconstructed topography in landslide susceptibility mapping. According to the method employed in this study, terrain is generalized by the contours passed through the convex slopes of the valleys that were formed by fluvial erosion. Therefore, slope conditions before landsliding can be obtained. The reconstructed morphometric and geomorphologic units are taken into account as a conditioning parameter when assessing landslide susceptibility. Two different data, one of which is obtained from the reconstructed DEM, have been employed to produce two landslide susceptibility maps. The binary logistic regression is used to develop landslide susceptibility maps for the Melen Gorge in the Northwestern part of Turkey. Due to the high correct classification percentages and spatial effectiveness of the maps, the landslide susceptibility map comprised the reconstructed morphometric parameters exhibits a better performance than the other. Five different datasets are selected randomly to apply proper sampling strategy for training. As a consequence of the analyses, the most proper outcomes are obtained from the dataset of the reconstructed topographical parameters and geomorphologic units, and lithological variables that are implemented together. Correct classification percentage and root mean square error (RMSE) values of the validation dataset are calculated as 86.28% and 0.35, respectively. Prediction capacity of the different datasets reveal that the landslide susceptibility map obtained from the reconstructed parameters has a higher prediction capacity than the other. Moreover, the landslide susceptibility map obtained from the reconstructed parameters produces logical results.

Structural, mass-wasting and sedimentation processes along an active dextral shear zone beneath the Gulf of Saros and the NE Aegean Sea were investigated on the basis of new high-resolution swath bathymetric data and multi-channel seismics. A long history of dextral shearing operating since the Pliocene culminated in the formation of a NE-SW-trending, ca. 800-m-deep basin (the so-called inner basin) in this region, which is bordered by a broad shelf along its northern and eastern sides and a narrow shelf at the southern side. The western extension of the North Anatolian Fault Zone (the Ganos Fault) cuts the eastern shelf along a narrow deformation zone, and ends sharply at the toe of the slope, where the strain is taken up by two NE-SW-oriented fault zones. These two fault zones cut the basin floor along its central axis and generate a new, Riedel-type pull-apart basin (the so-called inner depression). According to the bathymetric and seismic data, these basin boundary fault zones are very recent features. The northern boundary of the inner depression is a through-going fault comprising several NE-SW- and E-W-oriented, overlapping fault segments. The southern boundary fault zone, on the other hand, consists of spectacular en-echelon fault systems aligned in NE–SW and WNW–ESE directions. These en-echelon faults accommodate both dextral and vertical motions, thereby generating block rotations along their horizontal axis. As the basin margins retreat, the basin widens continuously by mass-wasting of the slopes of the inner basin. The mass-wasting, triggered by active tectonics, occurs by intense landsliding and channel erosion. The eroded material is transported into the deep basin, where it is deposited in a series of deep-sea fans and slumps. The high sedimentation rate is reflected in an over 1,500-m-thick basin fill which has accumulated in Pliocene–Quaternary times.

Seismic profiling, bathymetric and physical oceanographic data collected from the Canakkale Strait revealed that the morphological evolution of the strait has been controlled by tectonic activity, and sediment erosion and deposition. Sediments in the strait have been sourced mostly by rivers draining the Biga Peninsula during lowstand periods. In highstand periods, by contrast, deposits in the strait were reworked by currents. The seafloor morphology of the Canakkale Strait is also controlled by a sequence of factors ranging from tectonics to current erosion and deposition. Channel deposits overlying the basement are being eroded at the narrower, meandering central section of the strait (the Nara Passage) due to high current velocities. The eroded sediments are deposited in the relatively linear and wider, northern and southern sectors of the strait exposed to low current velocities. As a result, the high-energy areas are more deeply incised due to the erosion, whereas deposition elevates the seafloor in the areas exposed to lower current energy. Three strike-slip faults, which possibly relate to the activity of the North Anatolian Fault Zone, are responsible for the irregular shape of the strait and this, in turn, controls the current velocity along the strait. The high-energy conditions probably commenced with the latest invasion of Mediterranean waters some 12 ka b.p., and have continued as a two-layered current system to the present day.

The Quaternary evolution of the Gulf of Izmit, situated on the tectonically active North Anatolian Fault Zone (NAFZ), was investigated using seismic reflection, paleontologic, and sediment textural data. On the basis of seismic stratigraphic and sedimentologic-paleontologic interpretations, four depositional units were distinguished within the Plio-Quaternary sequence of the Gulf of Izmit. According to these data, Plio-Quaternary deposits supplied from the northern terrestrial area started to accumulate during a progradational phase, in a south-facing half-graben. A coarse-grained sedimentary unit prograding into the gulf from the south since 200 ka indicates a dramatic variation in the evolution of the gulf, with the initiation of a new strike-slip fault of the NAFZ and a corresponding uplift of the Armutlu Peninsula in the south of the gulf. During the evolution of this fault from a wide shear zone consisting of right-stepped strike-slip faults and pull-apart basins to a localized principal fault zone, sediments were deposited under the influence of northerly prograding terrestrial and shallow-marine conditions due to relative sea-level fluctuations in the Marmara Sea. During this period, the Gulf of Izmit was invaded mainly by Mediterranean and partly by Black Sea waters. In the latest glacial period, shallow areas in the gulf became subaerially exposed, whereas the central and western sub-basins of the gulf turned into lakes. The present evolution of the Gulf of Izmit is controlled by the after effects of the new rupture of the NAFZ and the estuarine nature of the gulf environment. © Springer-Verlag 2007. Istanbul Üniversitesi Acknowledgements This paper is based on the MSc thesis of Erdal Dolu. We gratefully acknowledge the captains and crews as well as the scientists and technicians of the R/V Arar of Istanbul University, and the R/V TCG Çubuklu of the Turkish Navy, Department of Navigation, Hydrography and Oceanography, for their help during the bathymetric and seismic surveys. We thank Dr. Timur Ustaömer for his very valuable criticism. We also acknowledge the helpful comments of two anonymous referees and the editor of the journal, Dr. Burg Flemming, to improve the paper.

The Strait of Istanbul (SoI) (Bosphorus) is a narrow valley, which has evolved tectonically from a stream, and in which thick sediment deposits have accumulated in the course of its evolution. Detailed seismic and multi-beam bathymetric data have revealed that the upper parts of the deeper channel deposits consist of parallel strata, which have mostly been eroded subsequently to their deposition. The resulting erosion surface is represented by the present channel floor in the strait, the estimated volume of the eroded material being approximately 2×108 m3 . Erosion rate and seafloor morphology indicate that the flow direction was from the south to the north. This inner channel may have been formed by an abrupt flooding of the Black Sea by Mediterranean waters at the beginning of the latest connection between the Marmara and the Black seas. Subsequently, the Mediterranean bottom current of the modern two-way flow system, which was established at about 5–4 ka b.p., has given the latest shape to the strait floor.