Geomorphological Research Research Articles

Numerical simulation of landscape evolution and mountain uplift history constrain—A case study from the youthful stage mountains around the central Hexi Corridor, NE Tibetan Plateau

Landscape evolution models (LEMs) are essential tools for analyzing tectonic-climate interactions and reproducing landform-shaping processes. In this study we used a LEM to simulate the evolution of the mountains from the central Hexi Corridor in the northeastern Tibetan Plateau, where the climate is arid and the surface processes are relatively uniform. However, there are pronounced differences in the topography between the mountains around the central Hexi Corridor. The East Jintanan Shan, West Jintanan Shan and Heli Shan are located in the northern part of the corridor; and the Yumu Shan in the southern part. Firstly, several representative areas were selected from these mountains to analyze the topographic characteristics, including the uniform valley spacing, local relief, and the outlet number. Secondly, a LEM for these areas was constructed using the Landlab platform, and the landscape evolution was simulated. With uniform valley spacing and other topographic characteristics as the criteria, we compared the realistic and simulated terrain for different model ages. Finally, based on the similarity of the simulated and realistic terrain, we estimated the timing of the initial uplift and the uplift rate of the four mountain ranges. The results are consistent with previous geological and geomorphological records from these youthful stage mountains that have not yet reached a steady state. Our findings demonstrate that LEMs combined with topographic characteristics are a reliable means of constraining the timing of the initial uplift and the uplift rate of the youthful stage mountain. Our approach can potentially be applied to other youthful stage mountains and it may become a valuable tool in tectonic geomorphology research.

Modelling the Maritime Cultural Landscape of the Costiera Amalfitana: The First Three Seasons of Research (2016–2018)

Human activity along the Amalfi coastline in Italy has been tied to the sea for millennia – for sustenance, migration, trade, warfare, and leisure. As a result, this region has an equally rich and extensive maritime cultural landscape composed of tangible and intangible elements. In 2016, a multi-disciplinary project began efforts to model and to understand changes within this landscape, and this essay presents the preliminary results of our first three seasons of work. Some efforts, such as the documentation of maritime cultural heritage in local museums, archival work, and geomorphological research proceeded smoothly. Unexpectedly, however, little material from the pre-modern era was found under water, adding questions to this study that future work in the Marine Protected Area west of Positano may answer.

Recent advances on geomorphology of the Gorce Mountains, the Outer Western Carpathians – state-of-the-art and future perspectives

The increase of geomorphological research during the last decades in the Gorce Mts. caused the need for state-of-art review papers. The Gorce Mountains were formed as an isolated massif with Mt Turbacz (1310 m a.s.l.) as the highest summit. River channels are remodeled by sudden and high-level floods with the critical impact of log jams. The main processes influencing hillslope relief were landsliding, run-off, and tree uprooting. The review suggests the following issues await for studies: a long-term landscape evolution, monitoring of morphogenetic processes, and origin of landslides with their contribution to denudation rates. Also, current biomorphodynamics (uprooting process) has not been sufficiently studied.

Climatic geomorphological research at the pacific geographical institute, feb ras. (Main directions and achievements; 1971-2021)

Climatic geomorphological research at the pacific geographical institute, feb ras. (Main directions and achievements; 1971-2021)

Research on spatial feature differentiation of basin river network geomorphology based on multifractal algorithm

Using multi-fractal algorithm to scientifically quantify watershed morphology is one of the hot spots of geomorphology research. In this paper, based on the DEM data of the Northwest China Basin (Daxiahe), the remote sensing images of the Daxia River Basin were processed. The multi-fractal model was used to extract and analyze the multi-fractal characteristics and quantified characteristic parameters of the Daxia River and 7 sub-basins of the river system, and discussed the geomorphic significance of the spatial characteristics of the watershed. The results showed that the multi-fractal spectrum of the watershed was in the shape of a right hook (Δf < 0). The span of the singular index Δa was between 0.860 and 1.160, and the value was relatively small. This indicated that the Daxia River watershed was evenly distributed in most areas, and the water system was not fully developed. The average values of the multi-fractal spectral height difference (Δf) and the singular index distribution range (Δa) from downstream to upstream were increasing (1.184∼1.570) and decreasing (1.160∼0.933) in sequence, which indicated that the proportion of the geomorphic unit with the smallest slope in the watershed increased sequentially from downstream to upstream, and the change of geomorphic shape from upstream to downstream tended to be complicated. This study is of great significance to effectively solve the complex problems in geomorphology and to master the characteristics and laws of various geomorphological phenomena.

Environmental impact of weathering and soil formation in geomorphological research

Weathering is a part of geomorphic processes leading to the disintegration and decomposition of rocks and minerals on the earth’s surface as a result of physical and chemical action that leads to the formation of soil being a most vital natural resource of rock weathering. Development of soils in an environment enhances plants dependence on it for growth, and man depends directly or indirectly on plants for food, thus the functions of soil as a fundamental interface, providing an excellent example of the integration among many parts of the earth system. Hence, geomorphology research being based on processes of the earth’s surfacing that result into most of the physical features seen on the face of the earth.

Environmental impact of weathering and soil formation in geomorphological research

Environmental impact of weathering and soil formation in geomorphological research

Analysis of Mountain Relief for the Causes of Snow Avalanches

The descent of avalanches is quite a usual phenomenon for the Ukrainian Carpathians, as well as for the conditions of mountain terrain in general. The Gorgany range of the Carpathian mountains is a typical avalanche-prone territory. Avalanches cause significant damage to forestry and may lead to casualties. Therefore, descent of avalanches has for a long time been a subject of fundamental research in geomorphology, meteorology, topography, photogrammetry and GIS technologies. Using photogrammetric mapping, we analyzed the causes of the descent of one of the largest avalanches in the Ukrainian Carpathians for the past 15 years. The avalanche fell from Poliensky mountain in the Gorgany mountain range in 2006, causing destruction of a great amount of forest. The main causes of avalanches were divided into two groups, the first including more or less stable factors caused by impact of terrain and somewhat less by solar radiation and the second group comprising meteorological factors, such as prolonged snowstorms and snowfall, that is, different fluctuations in weather. The main attention was paid to the first group of factors. For this purpose, a digital terrain model (DTM) of the study area was developed, visualizing the terrain, demonstrating the studied slope of the mountain along which the avalanche slid. According to the digital model, we developed maps of the steepness andexposition of the slope. Also we calculated the coefficient for solar radiation incident on the slope and which depends on the height of the Sun above the horizon and the coordinates of the slope. Using these data, the illuminance map of the Poliensky mountain area was developed. Studies conducted using GIS technologies led to the conclusion that the determining factors that triggered the powerful avalanche from Poliensky mountain were the great steepness and length of the slope, as well as the absence of forest at the top of the mountain, i.e. at the beginning of the avalanche track.

Hipóteses, observação e insights na evolução do conhecimento geomorfológico: a importancia do trabalho de campo

Um debate importante no âmbito da Filosofia da Ciência é aquele que discute como a Ciência avança e qual a importância da observação nesse processo: (1) para alguns a observação da natureza em casos particulares permite reconhecer padrões, e por meio destes é possível se realizar generalizações e obter avanço no conhecimento; (2) para os outros, o progresso se dá através da formulação quase aleatória de hipóteses que seriam testadas empiricamente. Este debate é importante para a Geomorfologia, pois permite verificar o papel e a importância do trabalho de campo na pesquisa geomorfológica. O tema foi abordado com base na análise do desenvolvimento e desdobramentos de duas pesquisas conduzidas pelo primeiro autor deste texto. Os resultados obtidos demonstram que a Geomorfologia progride através das duas formas e que ambas, na prática da pesquisa, se confundem. Paralelamente concluiu que, embora o teste de hipóteses seja o caminho mais comum, os insights oriundos da observação direta da natureza possibilitam descobertas inovadoras. Por fim, as análises realizadas permitem concluir que o trabalho de campo ainda é essencial na pesquisa em Geomorfologia.

Snail assemblages in Holocene floodplain research – an example from the southern Caucasus

Abstract. During the last decades, rivers and their deposits in different regions were intensively studied to better understand the late-Quaternary landscape evolution and former human activities. One proxy for paleoecological and paleoclimatic reconstructions is the analysis of gastropods (snails) from carbonatic river sediments. In the scope of this study, we investigated gastropod assemblages from a Holocene fluvial sediment–paleosol sequence at the upper Alazani River in the southeastern Caucasus. On the one hand, we aimed to derive reliable independent information about possible long-lasting human activity since the late Neolithic–Chalcolithic in the upper Alazani floodplain. This was formerly suggested by n-alkane biomarker vegetation reconstructions from the fluvial sediments. However, the reliability of that method is still debated. On the other hand, we aimed to obtain reliable information about a formerly suggested, possibly tectonic-driven, large-scale shift of the river course during the Late Holocene. In agreement with the n-alkane biomarkers, our results demonstrate that the studied site was free of the natural forests during the Early and Middle Holocene until ca. 4.5 cal kyr BP. Since this contrasts with a pollen-based vegetation reconstruction from a neighboring floodplain that was covered with forests during that time, the open vegetation in the upper Alazani valley was probably caused by continuous settlement activity as is also indicated by archeological finds in the sequence. Therefore, using our paleoecological proxies it is possible that we identified a settlement center in the upper Alazani floodplain that was populated from the late Neolithic–Chalcolithic. This center was not known thus far, since the settlement remains are covered by thick floodloam today that hindered their detection during archeological surface surveys. Therefore, our findings suggest that the area in the southern Caucasus region that was settled during the late-Neolithic–Chalcolithic period should have been larger than was known thus far. Furthermore, increasing contributions of wetland gastropods since ca. 4 cal kyr BP confirm a local shift of the river course towards the investigated site during the Late Holocene, possibly linked with ongoing tectonic activity. However, in contrast to former suggestions our gastropod assemblages indicate a slow rather than abrupt process. Our study demonstrates the high value of gastropod assemblages for geoarcheological and geomorphological research in floodplains with carbonatic river sediments at both a regional and local spatial scale.

Putting the Anthropocene into Practice: Methodological Implications

The foundational premise of the Anthropocene, constant across the range of proposed definitions, is that the biophysical world is now profoundly social. This carries substantive methodological implications: If the environment is ecosocial, surely the way it is studied must be, too. Yet, as our bibliometric analysis demonstrates, the bulk of academic articles on the Anthropocene published between 2002 and 2019 focus on its conceptual implications rather than embracing its analytical consequences. Further, of the subset of articles that engage the Anthropocene empirically, fewer than a quarter employ interdisciplinary methods at even a cursory level. In response, we outline an alternative approach, critical physical geography (CPG), which enables researchers to pick up the methodological and conceptual gauntlet thrown down by the Anthropocene. Work in CPG begins from the premise that all biophysical questions are also social, but it goes beyond a simple mixed methods approach to emphasize the politics both of how knowledge is produced and of how it is taken up outside academia. We illustrate the utility of a CPG approach for analysis of the Anthropocene via succinct examples of research in critical dendrochronology, geomorphology, and remote sensing.

IMPACTS OF COVID-19 ON GEOMORPHOLOGICAL FIELDWORK: EXPLORATION OF NEW INITIATIVES AND DIMENSIONS

The novel coronavirus disease (COVID-19) has already changed the world in many respects, and its impact cuts across many fields of human endeavours. An area of temporary setbacks in geomorphological research posed by the pandemic is in the restriction placed on fieldwork exercise. Apart from bringing a lot of constraints to fieldwork, the need to meet the learning outcomes ensured that the already in-use technologies were easily adapted to simulate the necessary fieldwork in evaluating dynamics in geomorphological environment and the natural world. Despite the success, however, the fieldwork remains ‘signature pedagogy’ for geography, geomorphology and any other Earth Science disciplines. The dynamic nature of landforms, the serendipity of on-site field training and exercises, the ability to have a first-hand experience of field phenomenon, etc. are some of the expected rewards that could not be simulated remotely. Hence, when COVID-19 pandemic is over, the aspects of fieldwork should not be jettisoned for the simulated alternatives embraced in the pandemic. The two should work hand-in-hand for the diverse fields of geomorphological research.

STUDY OF THE HOLOCENE STAGE OF FORMATION OF THE DNIESTER VALLEY IN THE EASTERN CARPATHIAN FORELAND

The article describes the main stages of studying of the floodplain and the first floodplain terrace of the Dniester river within the Eastern Carpathian Foreland fragment of the valley, and evaluates the results of existing studies. It is discovered that during all the stages of the research morphological and morphometric parameters of the floodplain and the first floodplain terrace of the Dniester river, morphology and facie structures of the alluvial accumulations, as well as palynological analyses of biogenic accumulations buried in an alluvial series are performed. The results obtained during the palynological analyzes are used to date the erosion-accumulation cycles and to reconstruct the physical-geographical conditions of the time of the floodplain and the first floodplain formation of the Dniester terrace. The radiocarbon dating of biogenic sediments buried in alluvial series is also actively conducted at the last stage of the research. The array of geological and geomorphological information collected at the first two stages of research made it possible to establish that, first, the first floodplain terrace and floodplain were formed during the Holocene in the Dniester Valley. The first floodplain terrace (the height of which reaches 4–6 m above the Dniester riverbed) can be considered as a high floodplain which is often covered by high floods. The terrace is accumulative, but unlike all other terraces of the Dniester it is devoid of the loess cover. In the cross-sections of its accumulations the deposits of the alluvium of the channel facies builted of pebbles are exposed and covered with the alluvium of the floodplain facies composed of sands, sandy loams and loams. The total thickness of alluvium reaches 9–10 m and it doesn’t varysignificantly downstream of the Dniester. Except the Upper Dniester basin, where the thickness of the alluvium increases to 10–18 m, and the layers of peat are found. The floodplain is 4–5 m above the Dniester riverbed and is built of alluvium of the channel facies, dominated by sand and pebble series. In someplaces floodplain is covered with sandy or loamy deposits of floodplain facies. Secondly, in the Eastern Carpathian Foreland part of the Dniester valley the course of fluvial morpholitogenetic processes was regulated not only by climatic changes and neotectonic movements, but also by human economic activity. During the XIX–XX centuries especially large-scale human influence was on the Dniester riverbeds by construction of flood ramparts, reclamation canals, etc. The results of recent geomorphological research conducted within the studied fragment of the river valley particularly palynological and radiocarbon dating have significantly improved the idea of morphology, structure and history of floodplain formation and the first floodplain terrace of the Dniester. The research revealed that the accumulation of alluvium of the first floodplain terrace which is above the Dniester riverbed reaches 5,5–6,5 (7) m and started to develop in the late Pleistocene (Bølling–Allerød interstadial) (13 000–11 000 years ago (GI–1)). Presumably in the early Dryas (11 000–10 000 years ago (GS–1)), the first floodplain terrace was dissected by the meandering channel of the Dniester. The alluvial deposits that fill these large paleomeanders are still well preserved and are often exposed in the ledges of the first terrace. The further development of the floodplain and first floodplain terrace of the Dniester river was taking place in several stages such as the end of the boreal, the beginning of the atlantic, the end of the atlantic, subboreal, the beginning of the subatlantic, as well as during V–VI, X–XII and XIV–XVI centuries. These stages are identified in correlation with the cycles of humidification of the climate and the growth of fluvial activity of riverbeds (flood phases). As a result of the intensification of erosion-accumulation activity of the Dniester the two – three levels of Holocene floodplain were formed up to 4–5 m and 3–4 m high. The first traces of human activity within the studied fragment of the Dniester valley were dated by subboreal and recorded by the presence of grain pollen in the spore-pollen diagrams of Mainych (Upper Dniester Basin) and Tsvitova (Galician-Bukachiv Basin) sections. Key words: Dniester valley; floodplain; the first floodplain terrace; alluvium; phases of floods; Allerød; early Dryas; Holocene.

Coastal Boulders on the SE Coasts of Cyprus as Evidence of Palaeo-Tsunami Events

Cyprus has a long history of tsunami events, as noted by archaeological and geological records. At Cape Greco (southeastern Cyprus) large boulders have been noted, however, no detailed geomorphological research has taken place so far and the related high energy event was undated until now. Our research aims to record in detail and interpret these large boulders deposits. The boulders, located between ≈3 and 4.5 m a.m.s.l., are fragments of an upper Pleistocene aeolianite, which is overlaying unconformly a lower Pleistocene calcarenite. Dimensions and spatial distribution of 272 small, medium, and large boulders were documented, while their precise distance from the coastline was recorded by field mapping and remote sensing, using Differential GPS (DGPS), drone, and Geographic Information Systems (GIS) technics. Field data were subsequently combined with hydrodynamic equations, in order to determine the extreme event(s) that caused their transport inland, and radiocarbon dating was accomplished on three samples of Vermetus sp. to determine the chronological context. Our findings appear to broadly correlate with the 1303 AD tsunami, which has displaced at least part of the studied boulders, and one other undocumented event at AD 1512-1824. The large number of boulders and sizes in our study area further indicate that their dislocation is most likely owed to multiple events from various sources.

Cartographic Extrapolation as Method for Forecasting Natural Phenomena and Processes

All known forecasting methods cannot do without the help of maps when it comes to natural phenomena and processes. Geographic forecasting can be considered as predicting geographic phenomena or processes that cannot be explored. Identity of the methodology for forecasting the dynamics of phenomena in time and their propagation in space makes it possible to transfer the patterns that are true for time sequences to spatial series. In contrast to specialized forecasting methods developed by individual sciences, cartography provides a researcher with a general forecasting method called cartographic extrapolation. In this case the extrapolation is understood as the spread of patterns obtained in the course of cartographic analysis of a phenomenon or a process to an unexplored part of this phenomenon or process to another territory, for the future. The foregoing is considered on the example of a map of Modern vertical movements of the Earth’s crust in the Republic of Belarus which is compiled according to geophysical data and repeated leveling. Predictive patterns and expectations are highlighted while applying the method of cartographic extrapolation on the map. The efficiency of cartographic extrapolation is increased with the complex use of different methods. The interaction of cartographic and remote methods is of particular importance. Joint analysis of maps, aerial and satellite images obtained from different heights and in different ranges helps to predict general global, regional or local patterns. An example of this is geological and geomorphological research. Maps of different contents and the results of interpretation of aerial photographs have been used to predict the neo-tectonic structure of the territory in the zone of junction of the Mikashevich ledge of the crystalline basement and the Turov depression in the Belarusian Polesie.

Do reconstructed landforms have multifractal characteristics? A case study at an opencast coalmine dump in the loess area of China

Opencast coal mining causes large changes in landform. The geomorphological features of the reconstructed landform have not been fully understood in the loess area. To quantify the characteristics of the reconstructed landform, multifractal analysis and Principal Component Analysis (PCA) were applied to classify three soil dumps, located at the Antaibao opencast coalmine in China. Most parts of the reconstructed soil dumps had multifractal characteristics. Multifractal parameters reflected heterogeneity of the reconstructed landform from surface relief, regularity and variance in elevation, and the results of PCA further provided a good explanation of the differences and similarities among the three soil dumps. Sub-areas of the South Dump (S1, S2, S3, and S4) were clustered together and this grouping was explained by relatively high D(0), ɑmax and D(q)min, whereas sub-areas of the remaining dumps were sparsely distributed. Long-term restoration and soil erosion may cause the homogenization of the reconstructed landform. Moreover, multifractal parameters, D(q)min, D(0), D(1), D(2), ɑmin, and f(ɑmin) were significantly correlated with Normalized Difference Vegetation Index (NDVI), suggesting susceptibility of the restored vegetation to landform development. Therefore, to improve revegetation practice, micro-topographic measures and silviculture technology are both needed in post-mining areas. The micro-geomorphological patterns could not only improve the efficiency of water use, but also provide a basis for the evolution of geomorphological research in the loess area of China.

Volcanic Geomorphology: A Review of Worldwide Research

The purpose of this article is to provide an overview of academic research on volcanic geomorphology, through the use of bibliometric analysis and bibliographic visualization maps for the discernment of its growing interest by the academy in the last 30 years. It is sustained on the publications indexed in the Scopus database between 1956 and 2019, obtaining relevant information on scientific production, following the methodological structure of a rigorous bibliometric process, which ranges from the search for descriptors or keywords to the configuration of visualizations of tables and maps that allowed to consider the contributions by authors, institutions, journals and topics that have shaped the evolution of this field of study. The generations of bibliometric maps allowed understanding the intellectual structure of the field of study made up of 707 articles where the analysis of co-occurrence of author keywords showed six main lines of research that, combined with the co-citation maps, allowed understanding the breadth of intellectual structure. Extensive information is provided on the thematic that other investigations partially addressed or failed to capture their current status. Considering that the results allow us to identify areas of current interest and the potential of research in volcanic geomorphology.

A characteristic periglacial landform: Automated recognition and delineation of cryoplanation terraces in eastern Beringia

AbstractAutomated recognition and delineation of specific landforms and their constituent elements ranks among the most active areas of contemporary geomorphological research. This study contributes to that literature by applying semi‐ and fully automated recognition procedures to upland periglacial geomorphic landscapes. The Cryoplanation Terrace semi‐Automated Recognition (CTAR) algorithm utilizes basic terrain parameters to identify locations of cryoplanation terraces (CTs) from the high‐resolution ArcticDEM. Using a multistep process, candidate areas are identified based on morphometric characteristics. CTAR uses terrain derivatives to search ridges, hills, and mountains for flat areas bounded by abrupt breaks in slope. Because CTs are found exclusively in upland periglacial environments, some locations require that low‐lying areas be filtered out. To assess accuracy, CTAR was tested at five local study sites distributed across eastern Beringia, each containing multiple CTs delimited manually in a previous study. CTAR performed well, with an overall accuracy of 90%. A strong linear relationship exists between the size of CTAR‐delimited terraces and those identified in a previous study through air‐photo interpretation. In addition to identifying nearly all of the CTs in the five study areas, a fully automated version of the algorithm (GEE‐CTAR), implemented in Google Earth Engine, identified nearly 8,000 previously unmapped potential CTs in the Seward Peninsula region of western Alaska. The ability to identify CTs from digital elevation models provides a useful tool for recognizing and delineating upland periglacial topography. Objective recognition of large erosional landform elements created by periglacial processes is a critical step in developing the field of periglacial geomorphometry.

STUDY ON THE APPLICATION OF AIRBORNE LIDAR IN SEISMIC ACTIVE FAULTS IN THE NORTHERN RIM OF QINLING MOUNTAIN AND THE PIEDMONT OF HUASHAN IN CHINA

Abstract. Seismic active faults are closely related to earthquake disasters. Active faults determine the location and magnitude of destructive earthquakes. Therefore, strengthening active fault investigation and research is one of the main ways to reduce earthquake disasters. Airborne LiDAR, as a measurement method that can quickly obtain large-area and high-precision DEM results, can not only obtain structural distribution features of large-scale study areas on a macro scale, and determine the location and trend of active faults, but also be used to identify microstructural landforms and take researches on fine geomorphic structural features. In this paper, based on the detailed introduction, analysis and summary of the technical schemes, data processing and application of the airborne LiDAR technique in the northern margin of the Qinling Mountains and the Huashan Piedmont Fault Zone, it was demonstrated on the basic methods and technical advantages in seismic active faults and geomorphological research work of the airborne LiDAR technology, and a new and efficient method for seismic fault study was provided.

Tidal impacts on downstream hydraulic geometry of a tide-influenced delta

Variations in river hydraulic geometry (HG) are of fundamental importance to fluvial geomorphological research and catchment management. In tide-influenced river deltas, channel geometry displays a mixed scaling behavior since the channel forming discharge is of both tidal and river origins. This study aims to map the tidal signature on delta morphology in the Pearl River Delta (PRD) channel network. The model results of a 2D numerical model are used to analyze the spatial variations of river and tidal discharges and their relations with representative channel geometry throughout the delta. Downstream HG of the distributary channels in the PRD features distinct characteristics in three zones. The transition points in morphology, which splits the delta into river- and tide-dominated parts, coincide with those in the mean flow velocity, the ratio of maximum tidal discharge amplitude (MTDA) to fluvial discharge. The ratio of MTDA to river discharge scales with bifurcation order. The water level setup created by non-linear tidal and fluvial interactions affects the discharge division at tidal bifurcations. In general, the net tidal impact is to attenuate the inequality in discharge division in the PRD. The tide is non-negligible in the cross-sectional morphology and plays a decisive role in the formation of the river channel in the seaward portion of the delta.