
Karel ŠilhánUniversity of Ostrava · Department of Physical Geography and Geoecology
Karel Šilhán
prof. Ph.D.
dendrogeomorphology - landslides - dynamic geomorphology
About
162
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Introduction
Karel Šilhán currently works at the Department of physical geography and geoecology and Department of Biology, University of Ostrava and University of Hradec Králové. Karel does research in Dendrogeomorphology and Geomorphology. His current project is 'Sackung in non-glaciated landscapes: spatial and temporal behavior of deep-seated gravitational slope deformations in Outer Western Carpathians'.
Additional affiliations
September 2016 - present
September 2007 - present
Education
June 2020 - December 2021
March 2013 - June 2014
February 2007 - February 2007
Publications
Publications (162)
Establishing the link between landslide reactivations and their triggers is one of the key tasks for effective landslide risk assessment. However, to accurately determine the causes of landslides, it is necessary to obtain detailed chronological data on their past occurrences and analyze a larger number of landslides in the area to eliminate local...
Although creep is a relatively slow slope movement, it can precede catastrophic events, and therefore information on its past occurrence is crucial to assessing the extent of natural hazards. Dendrogeomorphic methods are very effective tools for analyzing different types of slope processes, but their use in creep studies is still very limited. In d...
Sedimentary and volcanic tablelands host the world's largest landslide areas, sometimes spanning hundreds of kilometers along escarpments. This study, employing new remote sensing-based mapping and drawing on an expanding body of literature on paleogeographic evolution, revises the extent, controls, and chronology of some of Earth's largest coalesc...
The construction of the magnitude-frequency relationship is one of the key bases for the estimation of landslide hazard. However, data on past landslide occurrence are mostly from archival sources, and it is assumed that only the largest events are recorded. This situation may result in a critical underestimation or overestimation of the resulting...
Complex or compound landslides, which combine different movement types with sliding planes at various depths and with varying movement acceleration frequencies, are highly demanding for landform mapping, movement monitoring and reliable hazard assessment. In this work, several techniques including dendrogeomorphological investigation were combined...
The dating of landslide movements is a unique opportunity to learn about their past in the absence of archival data. Dendrogeomorphic methods, based on the study of tree rings, offer an exceptional combination of accuracy and temporal range of dating. However, most landslide studies to date have been based on the analysis of macroscopic growth dist...
On the surface of complex landslide areas, other types of slope processes often occur in addition to the landslide movements themselves. However, in order to define the interrelationships or analyse their triggers, it is necessary to have chronological information on their past occurrence. In this study, a spectrum of tree-ring-based (dendrogeomorp...
Tree-ring analysis is currently a frequently used absolute dating method for spatio-temporal analysis of landslide movements. However, like all absolute dating methods, this approach has various limitations. One possible limiting factor is the inertia of tree growth responses to the influence of landslide movements. When landslide movements occur w...
Dendrogeomorphic dating of landslide movements is nowadays a frequently used tool for understanding past landslide behaviour. One of the most widespread growth disturbances induced by landslides is tree-ring eccentricity. However, extracting the landslide signal from the time series of its values is a challenge that has suffered from many shortcomi...
The escarpments of sub-horizontally deposited rocks represent regional centres of geomorphological activity whose evolution is controlled by the occurrence of different types of slope processes. Surprisingly, historical landslide activity on escarpments of Cretaceous rocks has not yet been studied in detail at the regional level using precise absol...
Tree-ring based chronologies of slide movements can serve as an important basis for determining landslide activity , assessing risk and triggers, or potentially predicting future landslide behaviour. Unfortunately, however, the landslide areas studied are often affected by another type of slope movement, namely creep, which can introduce a consider...
Dendrogeomorphic (tree-ring based) methods are an effective tool for determining the spatial and temporal activity of landslide movements. Moreover, the obtained chronological data can be used for the analysis of their potential triggers. However, the use of tree-ring based chronologies for defining trigger thresholds is very rare and has not yet b...
Knowledge of meteorological triggers of mass movements is crucial for determining the degree of hazards, but also for predicting their occurrence. Dendrogeomorphic methods (tree-ring based) have repeatedly provided data on historical landslide activity as a basis for detailed trigger analysis. However, the construction of long den-drogeomorphic chr...
Slope movements are one of the most widespread geomorphic processes and can cause material damage due to their rapid and unpredictable action. The structural-geological conditions of the slope can play an important role in the resulting activity of landslide movements, and their type and mechanism. The environments in which slopes with different st...
Destruction of river banks and gradual lateral fluvial erosion can be closely related processes. This study presents the potential of a unique combination of two dendrogeomorphological (tree-ring and root-ring based) approaches to reconstruct the intensity of lateral river erosion and reconstruct subsequent bank movements. The data on anatomical ch...
Determining the age of landslide events is crucial for determining landslide risk, triggers, and also for predicting future landslide occurrence. Currently, the most accurate method for dating historical landslide events is dendrogeomorphic analysis. Unfortunately, the standard use of macroscopic growth responses of damaged trees for dating landsli...
The chronology of past landslide movements is a key source of information for effective landslide hazard determination. Dendrogeomorphological methods are currently an effective tool for obtaining chronological data but still encounter limitations in extracting landslide signals from yearly series. These limitations can be reduced by introducing an...
The quantification of the intensities of tree growth responses to the impact of geomorphic processes is a modern research trend in dendrogeomorphology. It enables a more sensitive assessment of the activity of the studied geomorphic process compared to the traditional use of growth disturbances. The advanced definitions of individual intensity clas...
Detailed knowledge of the occurrence of debris flows in the past is key to understanding their linkage to changing climatic variables and their occurrence in the future. For a comprehensive understanding of the origin of these processes, regional reconstruction is optimal rather than detailed analysis of isolated catchments. This study presents the...
The southern coast of the Crimean Mountains is affected by both debris flows and snow avalanches. However, there is no systematic record of these dangerous natural hazards. Therefore, this study is aimed at compiling a chronology of snow avalanches and debris flows at one of the most exposed sites on the southern coast of the Crimean Mountains. Den...
Dendrogemorphic methods are a very accurate tool for dating past debris flows. Chronological data are very valuable, especially in the alpine zone, because climate change has a very intense impact on the frequency of debris flows here. However, at the same time, the applicability of dendrogeomorphic methods in this environment is limited by the lac...
The geological structure of a slope is one of the key factors that drives the development of landslide types. Various landslide types, although occurring in the same locality, can result in different spatio-temporal dynamics of their movements. Moreover, the presence of shallow creep movements on such slopes can modify the effect of slide movements...
Background and aims:
Understanding the mutual coordination of vegetative and reproductive growth is important in both agricultural and ecological settings. A competitive relationship between vegetative growth and fruiting is often highlighted, resulting in an apparent trade-off between structural growth and fruit production. However, our understan...
The dendrogeomorphic dating of past landslides can be limited by the speed or magnitude of movements, as they are sometimes too small to induce growth responses in trees standing on unstable slopes. As a result, movements of low magnitude are generally assumed to remain undetectable in standard macroscopic analysis of growth disturbances in tree-ri...
The result of tree-ring-based reconstruction of past landslide events is often the development of a single total chronology. This approach can be very effective for small homogeneous landslides. However, compiling chronological data from heterogeneous (often independent) zones of large complex landslide areas into one chronology can induce over- or...
The combination of accumulation and erosion processes is the dominant geomorphic agent forming the surface of bare sand accumulations. These unique biotopes are gradually vanishing; thus, knowledge of their past dynamics is of crucial interest. This study focused on the selected locality with bare sand in the Borská lowland (Slovakia). In total, ni...
Dendrogeomorphic dating is an effective tool for the assessment of past landslide activity. However, some complex landslide areas include zones of accumulated boulders that can represent geotopes with deteriorated conditions for the stable anchoring of tree roots. Under such conditions, wind gusts can easily cause stem tilting and subsequently be a...
The steep scarps of river terraces surrounding the floodplains of meandering rivers are locations with concentrations of active geomorphic slope processes. Thus, knowledge of their past behaviour and present-day activity is of high importance. This study presents a dendrogeomorphic analysis of five landslides occurring on river terraces in various...
Dendrogeomorphic-based landslide activity dating is a commonly employed scientific approach used to detect historical landslide events with subannual precision. Trees are dominantly used for this research, but in some localities, current dendrogeomorphic methods are not suitable due to their exclusive occupation by shrub species. Nevertheless, shru...
Recently, dendrogeomorphic methods have been increasingly used for the dating past-flood events, and tree-ring-based approaches are generally considered valuable tools in palaeohydrology. Several limitations of the approach are known, but their effects on the resulting chronologies have not been assessed or quantified. Thus, this study attempts to...
Picea abies L. Karst is undeniably one of the most important tree species growing in Slovakia. In addition to natural mountain spruce forests, monocultures planted in lower areas are also quite common. In this article, we analyze the climate–growth response differences between these two types of spruce stands in the context of local climate change...
Bembix rostrata (Hymenoptera: Crabronidae) is a conspicuous digger wasp, which is one of the most threatened species of bees and wasps in central Europe. Its distribution is restricted to sites with grey dunes or similar habitats, which B. rostrata needs for nesting. In the years 2012–2014, we have studied the ecological factors influencing the pre...
The Czech part of the Outer Western Carpathians (COWC) formed by flysch rocks is among the most landslide-prone areas in Europe. Recent LiDAR-based inventory mapping reveals that the area of the COWC encompasses more than 13,500 landslides, with some geological domains exhibiting > 20% of the surface area covered by landslides. Although mass moveme...
The degradation of forest ecosystems represents a severe environmental issue in anthropogenically modified landscapes worldwide. We demonstrated the negative impact of contaminated debris flow deposits on riparian forest in the Romanian Carpathians through the innovative combination of several dendroecological approaches. Reconstruction of debris f...
The knowledge of past landslide movement chronology is crucial for estimating future landslide development or for detailed analysis of triggers. A very precise approach to landslide history detection is based on tree ring analysis (dendrogeomorphology). The detection of landslide movements is based on dating growth responses induced by slope moveme...
As the use of the increment borer is supposed to be invasive, there is a question of how coring affects subsequent growth or the health of various tree species. Ten Picea abies (L.) Karst. trees in the Beskydy Mts. (Czech Republic) were analysed nine years after coring by an increment borer (June 2011) to determine their anatomical and growth respo...
Key message
Complex detailed analysis—3D extension of tension wood, Anatomical intensity and tree-ring eccentricity—of one Fagus sylvatica L. individual provides unique insight into tree growth response to landsliding
Compression wood formation and tree ring eccentricity of coniferous trees have often been used to date past geomorphic events becaus...
Unlike high-relief mountain areas, low-relief hilly landscapes are usually rarely affected by deep-seated gravitational slope deformations (DSGSDs). However, low-topography flysch thrust fronts can create suitable structural conditions for DSGSDs. The study area of the Kavalčanky ridge represents a relatively low-lying (<120 m of local relief) DSGS...
Flow-like landslides are a dangerous landslide type. They often express gradual movement or seeming dormancy, but occasional reactivation can, in extreme cases, result in catastrophic events. To predict their future behaviour, knowledge of past spatio-temporal development and relationships with hydrometeorological triggers is crucial. Moreover, reg...
The dating of past landslide events is one of the most crucial aspects of landslide research, leading to a better understanding of past landslide activity. Landslides can be extremely dangerous natural hazards, and thus, solving the relationships between their activity and climate variations is of high importance. For these purposes, data about pas...
The knowledge of spatial distribution of landslide events is crucial from forest management, landscape planning or hazard assessment point of view. Dendrogeomorphic approaches are actually a suitable tool for construction of past landslide behaviour due to known position of sampled trees. The position of trees on the landslide surface can influence...
Dendrogeomorphic dating of past landslide events is a valuable tool for the assessment of landslide activity, providing unique data for the analysis of triggers or the modelling of landslide behaviour in the future. Unfortunately, tree-ring-based methods as well as dating approaches suffer from some limitations. One of the less frequently addressed...
Landsliding is a major natural hazard; therefore, understanding its activity is an important objective worldwide. For the investigation of the current landslide events, dendrogeomorphic methods are commonly used as they allow quite a precise dating of individual events. Nevertheless, there is still a question of whether dendrogeomorphic methods can...
Landslide processes could be dangerous and occur not only under natural conditions but also on anthropogenic slopes of artificially accumulated spoil heaps. Establishing chronology of landslide activity is of crucial importance for landslide hazard assessment. Dendrogeomorphic methods are commonly used approaches for the reconstruction of past acti...
Sand dunes represent unique environments that increase the biodiversity, geodiversity, or ecosystem services of landscapes. The knowledge of past sand dune development is crucial for realizing their effective protection. Dendrogeomorphic methods represent an effective tool for the reconstruction of geomorphic processes, but their application in aeo...
This study represents the first palaeoflood discharge estimation using dendrogeomorphic evidence from two ungauged catchments in southern Crete. Dendrogeomorphological methods, rainfall-runoff and hydraulic modelling were applied to estimate the palaeoflood discharge of the 2000 flood event. We developed two scenarios (QHydraulic, QRR) of peak disc...
Dendrogeomorphic methods enable a very accurate reconstruction of spatio-temporal landslide behaviour. Unfortunately, existing approaches of spatial reconstruction suffer from many imperfections (e.g. dependence on tree age or impact of forest management). This study developed, presented, and tested a new approach for the spatial reconstruction of...
Giant catastrophic landslides (>10 8 m 3) dot the formerly glaciated mountain forelands of the eastern Patagonian Andes. From geomorphic mapping, sedimentological logs and radiocarbon dating, we infer the emplacement kinematics and approximate timing of giant landslides in moraines and other glacial deposits in the Lago Pueyrred on valley (LPV), Ar...
The Publisher regrets that this article is an accidental duplication of an article that has already been published, https://doi.org/10.1016/j.geomorph.2020.107471. The duplicate article has therefore been withdrawn.
The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/our-business/policies/article-withdrawal...
Bees and wasps inhabiting steppe formations are, according to recent red lists, among the most endangered species, quickly disappearing from local faunas of central European countries. Several species, which are specialised nesters in empty gastropod shells, show the opposite pattern. Based on their distribution maps, we found that these species ar...
Many of the volcanic plateau margins of the eastern, formerly glaciated, foreland of the Patagonian Andes are undermined by giant landslides (≥10⁸ m³). One cluster of such landslides extends along the margin of the Meseta del Lago Buenos Aires (MLBA) plateau that is formed mainly by Neogene-Quaternary basalts. The dry climate is at odds with numero...
Landslides are dangerous and destructive geomorphic processes that cause annual damage to human infrastructure or even loss of life. As recovery is very costly, knowledge of past landslide activities, a detailed analysis of triggers and prediction of future landslide development are important. Dendrogeomorphic (tree-ring-based) dating is the best s...
Magnitude–frequency (M–F) relationships represent important information on slope deformation and are used in hazard assessment or as supporting data for urban planning. Various approaches have been used to extract such relationships in the past, but most of these methods drove at the problem of exact events´ frequency determination. Dendrogeomorphi...
Catastrophic landslides represent one of the most dangerous natural hazards. Detailed knowledge about the pre-landslide behaviour of the affected slope is crucial for effective modelling of the landslide origin in the future or even for creating an early warning system. As precise retrospective reconstruction of slope movements in the pre-landslide...
The past geomorphic activity of flash floods in the Eastern Mediterranean has been poorly understood. Despite the general increase in mean annual temperature and decrease in annual precipitation totals, intense rainfall during strong cyclogenesis is still expected under a changing climate. The aim of this study was to identify past flash flood even...
Our study analyzes the growth response (release or suppression) of Norway spruce trees growing along a landslide zone in eastern Czech Republic. A total of one hundred and eighty-six increment cores were extracted from Norway spruce (Picea abies (L.) Karst.) individuals, which were affected by two different disturbances, the Girová landslide in May...
Landslides are frequently triggered by extreme meteorological events which has led to concern and debate about their activity in a future greenhouse climate. It is also hypothesized that dry spells preceding triggering rainfall may increase slope predisposition to sliding, especially in the case of clay-rich soils. Here we combined dendrogeomorphic...
An understanding of past landslide behaviour is crucial for the estimation of future landslide activity. In this respect, methods of absolute dating are frequently used for landslide history assessment. Dendrogeomorphic (tree ring-based) approaches are standard methods for the spatio-temporal reconstruction of landslide activity with annual to even...
Investigations of mass movement hazards need to be supported by accurate data regarding past frequencies of landslide reactivations. Dating landslide events using tree rings is a reliable approach for vegetated slopes in temperate climates. Despite the enhanced use of dendrogeomorphic research during recent decades, little is known about the specif...
The mechanisms and velocities of landslide movements are important information for assessing hazards associated with landslides. This contribution introduces a new approach in reconstructing the past rate of landslide displacement using dendrogeomorphic methods. The principle of this method is based on the analysis of exposed roots in tension crack...
The chronological aspects of landslide research are of great interest regarding the hazard assessment of landslide triggers. Dendrogeomorphic methods provide a good ratio of chronology length and dating resolution. An alternative to the standard dendrogeomorphic approaches used in landslide research (based on reaction wood analysis-a reaction to st...
Snow avalanches (SA) and debris flows (DF) are among the widespread geomorphic processes in high mountains. One of the most reliable method for determining their historical occurrence is related to dendrogeomorphical analyses. Sampling focused only on one process suffers from the noise caused by disturbances induced by the other process. Thus, the...
Dendrogeomorphic methods are frequently used for the analysis of past landslide behaviour and have become the standard approach used to date landslide activity. Unfortunately, many questions related to the application of tree-rings to landslide analysis remain unsolved. This study points to the significance of dividing a large complex slope deforma...
Detailed characteristics of 73 log steps (i.e., steps formed by a single key wood piece) in steep headwaters draining managed Carpathian forests were assessed together with channel- and wood-based thresholds for log step occurrence. The upstream threshold of log step occurrence can be assigned to those locations in stream longitudinal profiles, whe...
Wasps of the genus Gasteruption are predator-inquilines of bees nesting in cavities in wood, stems, galls, and vertical soil surfaces. During studies of hymenopterans associated with reed galls caused by flies of the genus Lipara we recorded three species. We provide the evidence that a rare European species Gasteruptionphragmiticola is a specializ...
Landslides are a type of mass wasting and denote any downslope movement of soil and rock under the influence of gravity; as such they can represent a dangerous natural hazard process, especially in case that they affect inhabited areas or transport infrastructure. Because the occurrence of landslides is typically favoured by terrain and lithologica...
The recent acceleration of gully erosion caused by environmental factors and human impacts has led to an enhanced demand for applied research in risk-prone areas worldwide. We investigated the dynamics of gullies that have recently threatened dwellings and railways in the foreland of the Eastern Sudetes (340-390 m a.s.l. in the NE part of Czechia)....
Wood jams represent an important ecological and morphological element in fluvial systems influencing sediment/instream wood transport and storage. erefore, the knowledge of jam ages is important in evaluating a jam's development and stability. is study presents a reconstruction of the chronological development of the largest wood jam in the wider a...
Gully erosion is a widespread natural hazard that causes substantial financial losses every year. Dendrogeomorphic (tree ring-based) methods are a good alternative approach for assessing gully development in forested areas. e majority of previous dendrogeomorphic studies dealing with erosion focused on sheet erosion or erosion rates in the active c...
Although large wood (LW) has been intensively studied in forested basins of humid temperate climates, data on LW patterns in different fluvial environments are rather scarce. Therefore, we investigated the dimensions, characteristics, longitudinal distribution, and dynamics of LW along a 4.05-km-long reach of an ephemeral channel typical of Europea...
High-magnitude hydrogeomorphic events in steep streams (e.g., debris flows and debris floods) are capable of transporting considerable quantities of bed material, including large wood, although wood pieces that are longer than the channel width are often perceived as relatively stable elements in narrow headwater channels. We investigated present l...
The effect of instream wood on stream hydraulics and geomorphic processes depends on wood and channel dimensions. We investigated abundance and characteristics (i.e., wood orientation, proportion of spanned channel width, stability and decay classes) of large wood (LW; defined here as having a length ≥1 m and a diameter ≥0.1 m) and small wood (SW;...
Hydrogeomorphic processes (HP) are dangerous natural hazards, particularly in areas with increasing settlement. The Mediterranean region is a highly endangered area, particularly due to its high sensitivity to environmental changes. Chronological information about past events occurrence is crucial for modelling its development in the future. This s...
This article presents a multidisciplinary approach to the assessment of slope deformation at the Lower Hodruša mining water reservoir, which is part of a UNESCO cultural heritage site. The multidisciplinary approach was used to develop remedial measures. The Lower Hodruša mining water reservoir is situated in the Hodruša-Hámre municipality near Ban...
Rock-slope failures represent a significant hazard along global coastlines, but their chronology remains poorly documented. Here, we focus on the geomorphology and chronology of giant rockslides affecting the Crimean Mountains along the Black Sea coast. Geomorphic evidence suggests that high (>100 m) limestone cliffs flanking the southern slopes of...
Hydro-geomorphic processes have significantly influenced the recent development of valley floors, river banks and depositional forms in mountain environments, have caused considerable damage to manmade developments and have disrupted forest management. Trees growing along streams are affected by the transported debris mass and provide valuable reco...
The initial employment of tree rings in geomorphic studies was simply as a dating tool and rarely exploited other environmental information and records of damage induced by earth surface processes within the tree. However, these unique, annually resolved, tree-ring records preserve valuable archives of past process activity on timescales of decades...
The High Tatras Mountains are known for frequent occurrences of hazardous geomorphic processes. Many occur at the same localities. This similarity of occurrence is typical of snow avalanches and debris flows, as snow avalanches tend to use debris flow channels. Dendrogeomorphic methods allow for the intraseasonal dating of scars left on stems and b...
Road-stream crossings constructed with culverts have the potential to alter geomorphic processes in adjacent stream channels. We examined changes in channel geometry and bed sediments in longitudinal profiles related to culverts at five paved forest road crossings with perennial headwater streams and two gullies initiated by point releases of water...
Montanogenic landforms are commonly viewed as hazards by society, but they are also holders of specific and uncommon morphology with unique dynamics that act as remarks on landscape history. The Velké pinky stopes in the Zlatohorská Highlands, Eastern Sudetes, are naturally revitalized post-mining landforms with long-term geoecological succession....
Instream wood can reside in fluvial systems over varying periods depending on its geographical context, instream position, tree species, piece size, and fluvial environment. In this paper, we investigate the residence time of two typical species representing a majority of instream wood in steep headwaters of the Carpathians and located under mixed...
Dendrogeomorphic chronologies of landslide movements are frequently used to investigate past landslide activity. Slide areas are often affected by other slope movements (e.g., creep) simultaneously. Trees growing on landslides record all types of ground movements, which potentially creates significant noise in tree ring based chronologies of landsl...
Dendrogeomorphic methods are frequently used in landslide analyses. Although methods of landslide dating based on tree rings are well developed, they still indicated many questions. The aim of this study was to evaluate the frequently used theoretical scheme based on the event–response relationship. Seventy-four individuals of Norway spruce (Picea...
Debris flows and debris floods cause frequent geomorphic hazards, even in the mid-mountains of Central Europe. In the Hrubý Jeseník Mountains (Eastern Sudetes, Czech Republic), strong anthropogenic interventions have created specific conditions for erosion, transport and accumulation of material released by debris flow/flood events. We present a de...
Debris flows are very frequent geomorphic agents that form relief of the High Tatras Mountains, which are the highest mountain range in the Carpathian arc. The knowledge of their history is based on lichenometric dating, historical orthophotos and incomplete archival records. Nevertheless, complete chronologies of debris flows at an annual resoluti...
Floods are an important geomorphic agent that accelerate sediment supply from bank failures. The quantitative proportions supplied by lateral inputs and the transport conditions of the channel can create local or extended accumulation zones within the channel reaches. These accumulation zones play an important role in the geomorphic regime of the s...