Geomorphological Research Research Articles

REVIEWS OF PERSPECTIVES ON CONTEMPORARY APPROACHES AND TECHNIQUES IN FLUVIAL SYSTEMS EVALUATION AND MANAGEMENT

This paper reviews fluvial geomorphology perspectives and methodologies for environmental sustainability by exploring and discussing major concepts, themes, and methodologies. To meet the multidimensional aspect of fluvial geomorphology research, multidimensional approaches are now used. Fluvial geomorphology examines river channel morphology and how it is shaped by fluid flows interacting with erodible or resistant boundaries. Understanding equilibrium conditions and thresholds is key. A systems perspective is needed - any river segment is influenced by upstream and downstream conditions as part of an integrated drainage basin system. Field surveys, mapping, remote sensing, and GIS provide important morphological data on river planform, cross-sections, longitudinal profile features, sediment characteristics, etc. Statistical analysis helps detect spatial patterns and trends. Assessing channel changes over long periods is often necessary to fully understand contemporary fluvial processes and forms. Sediment storage and release causes significant time lags. Major human impacts include land use changes affecting hydrology, sediment budgets, channel boundaries; and infrastructure interrupting continuity. Sustainable management requires addressing root causes. Watershed level processes like water balances, erosion patterns, etc. strongly influence fluvial systems - coordinating river channel and upland catchment interventions is key. Models like SWAT, MIKE-SHE, and ANSWERS simulate hydrological processes but have limitations. They require robust spatial datasets spanning geology, topography, land use, climate, etc. Overall, a multidimensional, scale-conscious, historically contextualized assessment framework is required for evaluating fluvial systems. The review highlights techniques and datasets for such integrated diagnosis.

The Application of Information Theory to Interpret Shore Platform Erosion Rates

Advancements in information physics have recently introduced the application of information theory to investigate physical systems. The behaviour of erosion at the granular scale is to date still a complex system to unpack, and therefore geomorphology research requires novel approaches to better inform the interpretation of temporal and spatial erosion patterns at different scales. This paper applies information theory concepts to re-evaluate erosional data that were measured on limestone surfaces of two shore platforms in Malta with a traversing micro-erosion meter (TMEM). By representing erosion rates through their information content using a Box-Cox style transformation of the raw data (application of an inverse normal distribution function to fractionally ranked data), it is possible to identify points and measurement periods that contribute to a disproportionately large share of unexpected erosion rates that could provide more insight into the causes of erosion rates. Despite the variations in the information content from erosion rates at individual measurement points, most points consistently contribute to a similar amount of information. These findings illuminate the importance of considering the informational value of erosion data to further understand the underlying physical processes and potentially improve predictive models.

Structural geological surveys and improvement of tectonic understating of the Pre-Ordovician/Tertiary Graben boundary in vicinity of Nicolaus Copernicus Polar Station, Svalbard

Researchers around the globe are on a quest to develop solutions to mitigate and prevent global warming and climate change. This includes facilitating the switch to renewable energies. Assistant Professor Slawomir Jack Giletycz, Director of the Polar Research Station in Svalbard and part of the Structural Geomorphology Research Group, Department of Earth Sciences at National Central University in Taiwan, is interested in glacial retreat in Svalbard, Norway. As the Earth warms, glaciers are melting and land that was previously buried by glaciers is being exposed. By studying this land, researchers can glean new insights. For example, Giletycz and his collaborators are performing geological mapping of areas that have been recently exposed to subaerial conditions due to the glacial retreat. They are working to develop new geological maps and interpret tectonic and structural settings. The researchers are also investigating fluvial system development and surveying particular glaciers. They are using unmanned aerial vehicles to capture aerial images of entire glacier river systems and can use the images to build a digital surface model that can be used in applications such as QGiS or ArcGiS. In the long tem, they can monitor the development of glacier fluvial systems such as sediment discharge. Another focus for the researchers is conducting plaeocoast surveys of the Kaffiøyra plain in western Svalbard. Excitingly, the researchers are the first humans to study Svalbard in this way and, through this work, they will make significant contributions to geological mapping and underpin geology, tectonics and structures.

Evaluation of geomorphological classification uncertainty using rough set theory: A case study of Shaanxi Province, China

AbstractGeomorphological classification is affected by classification principles, indicators, methods, and data resolution, which can lead to uncertainty in the results. Such uncertainty directly affects the quality and subsequent applications of geomorphological classification. To quantify and control the uncertainty, it is important to select an appropriate and effective method for evaluating the uncertainty of geomorphological classification. This study evaluated the uncertainty of geomorphological classification of Shaanxi Province at the ground‐feature class and image scales, which derived from rough set theory: rough entropy, approximate classification quality, and approximate classification accuracy. The three indicators helped effectively assess the uncertainty of geomorphological classification at multi‐scale and measured the degree to which different factors affected the uncertainty of geomorphological classification. The relative impacts of three factors on the uncertainty of classification decreased in the order of classification methods, data resolution, and classification indicators. This finding is helpful to objectively evaluate and control the uncertainty generated in the process and results of geomorphological classification, and can provide targeted reference and guidance for future geomorphological classification work, which is more conducive to decision‐making and application. At the same time, this study is also a beneficial supplement to the geomorphological research based on digital terrain analysis.

A low-cost UAV survey can unravel Baird's Tapir (Tapirus bairdii) trail network dynamics in a neotropical highland forest

UAV technology has transformed spatial data collection and high-spatial resolution analysis of diverse environments around the world. Its role within geosciences, ecology, engineering, and other sciences has been increasing withing the last decade. In ecological and geomorphological aspects, it offers a powerful tool for studying landforms, surface processes, vegetation, and animal behavior globally. Our study employs high-resolution UAV surveys to analyze Tapirus bairdii trail networks and their connection to the landscape in a Costa Rican highland paramo-forest national park. Using a DJI Phantom 4 V.2 UAV, we conducted a photogrammetric flight over 3.19 ha, producing datasets with a spatial resolution of 2.99 cm/pixel. These datasets facilitated geostatistical analysis of Tapirus bairdii trails, revealing their complexity and hotspots near lagoons. We investigated lagoon characteristics, finding that finer sediments spatially correspond with higher trail activity. This suggests that sediment types in lagoons influence Tapirus bairdii navigation, impacting trail network composition. Our findings highlight UAV technology's role in advancing ecological and geomorphological research in protected areas, providing insights into Tapirus bairdii behavior within highland ecosystems. Overall, to the date this is the first high-resolution UAV survey of Tapirus bairdii within these types of highland tropical environments.

Geomorphological analysis of the Antinaco‐Los Colorados valley, La Rioja province, Argentina

AbstractThe Antinaco‐Los Colorados valley (ALCV) is a tectonic depression located in the centre‐north of the province of La Rioja (Argentina), limited to both the east and west by mountain ranges, in the broken foreland region. Geomorphological research on environmental dynamics is important for both building a reference framework for further studies and for the development of the socio‐economic activities in the area. This study presents the main geomorphological features of the tectonic depression at the regional scale in order to identify the primary factors involved in its evolution and the landforms it contains. The ALCV is asymmetric, and it is filled by up to 1600 m of sediments along the western margin. Using literature, images, digital elevation models of the study area and field work, different morphologies were identified in the valley, mostly linked to Quaternary climatic and tectonic changes. These morphologies were grouped into three main morphogenetic units that characterize this landscape: the relict piedmont levels, the current piedmont and the fluvial‐aeolian plain. The identification of fluvial forms suggests that fluvial systems have been important during the evolution of the landscape. Aeolian accumulation features, currently mostly vegetated, were likely formed under drier climatic conditions than those at present and probably related to the last ice age or even more recent times. Successive reactivations of the overall system are not only tectonic, as evidenced by the structural lineaments that affect relict piedmont levels and the fluvial‐aeolian plain, but also climatic. Thus, the identified landforms suggest that climatic and tectonic variables account for the variations in the environment of the ALCV, affecting the reaccommodation of the exogenous geomorphological processes and the modelling of the relief.

The location of Tartessos: a fresh case for the reliability of Avienus’ Ora Maritima

Recent geomorphological, paleoenvironmental, and chronological evidence allows for a reconstruction of the coasts of southwest Iberia during the first millennium BCE that accords with descriptions of the region offered by authors of antiquity, most notably the description by the fourth-century CE Roman writer R. F. Avienus in his poem Ora Maritima. This poem contains information that appears to date from the sixth century BCE regarding, for instance, the pre-Roman polity of Tartessos. The reliability of this work as a historical source has been questioned for decades. Critics argue that the information is pertinent to our understanding of the literary, rather than historiographical, context of the Late Roman Empire. However, philological as well as historical analyses reveal no clear cause to doubt the documentary value of the Ora Maritima. Furthermore, geomorphological research makes it possible to identify most place-names in the poem; for example, the city embraced by the river Tartessos, apparently the political and trade center of the realm, may likely have stood on the present-day spit of La Algaida, which was an isle in the first millennium BCE. While this hypothesis has been advanced elsewhere, this article offers an entirely new set of evidences to support it.1

Geomorphological study of the debris flow events in the Harsovska River (Blagoevgradska Bistritsa catchment), observed within 2019-2023

Debris flow events in the Blagoevgradska Bistritsa catchment (SW Bulgaria) become more frequent in the past few years. To localize the debris source along the tributary system, the Harsovska River is chosen in this study. During the observation period a torrential event was registered in June 2023. The synoptic situation, which caused the flood, is re-analyzed and also geomorphological research is made for depositional landforms in the river channel for the period 2019-2023. In the study, the alluvial sediments are defined by grain size and also by morphoscopic study of pebble-sized grains. During the field research, two critical flood-risk sites are pointed, located in the Harsovo hamlet. The data about past debris flow events are collected from residents of Harsovo with interviews regarding their experience in this issue. In the period of the study, the main part of debris nourishment in Harsovska catchment is provided by the tributary Marulevska River, where active mass movement processes are registered. However, the alluvial profiles of both rivers – Marulevska and Harsovska, showed an alternation of coarser and finer materials, resulting of turbulent and calm discharge. Such periodical change in the sedimentary environment of the two compound rivers demonstrates their unsteady torrential character. Regarding the fortification activities in this area, at the moment some new forestation has been noticed. Still, the species, used to fortify the river banks are not suitable for the climate and hydrological regime of the region. The channel fortifications, built in the middle of the 20th century, currently are not maintained properly, which puts under threat of future debris flow events the settlements and infrastructure along this catchment.

Structural shifts in plant functional diversity during biogeomorphic succession: Moving beyond taxonomic investigations in an alpine glacier foreland

AbstractThe complex interrelation between plants and geomorphic processes is described in the concept of biogeomorphic succession. While ecological research on succession and community assembly has transitioned towards functional approaches, studies on functional diversity in biogeomorphic settings, particularly in glacier forelands, remain limited. In this study, we investigated abundance of vascular plant species and functional traits in an alpine glacier foreland using data from 199 plots. Our objective was to unravel the development of functional diversity during biogeomorphic succession. Specifically, the study determined whether structural shifts in functional diversity are associated with stability thresholds related to plant cover, geomorphic influence, and examined trait spectra for stages of biogeomorphic succession. Our findings revealed a nonlinear trajectory of functional diversity along the plant cover gradient, marked by two distinct structural shifts at 30% and 74% cover, corresponding to established stability thresholds. Along the gradient of geomorphic influence, we observed an increase in functional diversity until 54% of the plot area was affected, beyond which functional diversity declined below the initial level. The analysis of community‐weighted means of traits across four stages of biogeomorphic succession determined by plant cover and absence and presence of geomorphic influence revealed significant differences in trait values. In the transition to the biogeomorphic stage, associated with the identified initial structural shift, there is a shift from a prevalence of above‐ground adaptation and reproductive traits, such as leaf longevity, structure, growth form and mixed reproductive strategies, to an increased dominance of competitor species and traits related to below‐ground structures, including root type and structures, as well as vegetative reproduction. Our results contribute to understanding the relationship between vegetation succession and geomorphic influence by linking them to plant functional traits. This study advances beyond traditional taxonomic investigations by emphasizing functional approaches to biogeomorphic succession. Moreover, the functional trait data used in this study, easily downloadable from a public repository, can serve as a valuable template for future research in (bio)geomorphology, along with the employed methodologies.

Solute fluxes in headwater catchments with contrasting anthropogenic impact

Understanding the response of headwater catchments to increasing anthropogenic influences is one of the key issues in hydrological and geomorphological research. Two headwater catchments with contrasting human impacts on the environment were chosen to determine changes in surface water chemistry and solute fluxes. In one catchment, 22 % of the forest area was cleared in 2013 and in the other, 75 % of the arable lands was converted to grassland and forest in the last 25 years. Atmospheric input and solute mass balance were analysed using homogeneity Pettitt test. It seems that in both areas, a very important factor affecting solute fluxes was most likely changes, or lack thereof, in soil erosion. In the partially clear-cut catchment, a small clear-cut area and adequate protection of the soil cover had little effect on the stream water chemistry, and the total solute mass balance remained unchanged during the study period. In this catchment, the more pronounced effect on solute fluxes was using de-icing salts in winter, which contributed to a 62 % increase in total solute flux (mainly by supplying Na+ and Cl−, but also Ca2+, Mg2+ and K+). In a catchment with a decrease in arable lands, there was a 55 % decrease in total solute mass balance (including mass balance of Ca2+, Mg2+, Na+, K+, NH4+, SO4−, NO3−, Cl−) in the stream likely associated with a decrease in soil erosion and fertilization. In both catchments there was a decrease in total monthly atmospheric input (especially in input of NH4+, SO4− and NO3−) of 53 % and 21 %, respectively, over the study period. To summarize, the road salting has increased the amount of transported solutes in the stream and deteriorated surface water chemistry, while the reduction of arable land area has reduced the amount of transported solutes in the stream and improved surface water quality.

Geomorphological study of the origin of Mongolian Altai Mountains Lake depressions: implications for the relationships between tectonic and glacial processes

The lake depressions in the Mongolian Altai Mountains, and the issues related to their formation have yet to be thoroughly examined in previous research. Previous studies primarily focused on the paleogeographical evolution and glaciation dynamics of the Altai Mountains. This study presents relationships between tectonic and glacial processes that have formed the lake depressions, such asKhoton, Khurgan, Dayan, Khar (western), and Khar (eastern) in the Mongolian Altai Mountains. The depressions of Khoton, Khurgan, and Dayan lakes are situated along regional fault zones, extending in an northwest-southeast direction, forming intermontane depressions directly connected to the Mongolian Altai Mountains. However, the depressions of Dayan, Khar (western), and Khar (eastern) lakes have been dammed by moraine deposits in the near portion of the depression. The compliance matrix of tectonic geomorphological criteria indicates that the Khoton, Khurgan, Dayan Lake, and Khar (western) Lake depressions are more than 50% compatible. Similarly, the compliance matrix for glacial eomorphological criteria indicates more than 60% compliance for all lake depressions. The Mongolian Altai intermontane depressions are thus of tectonic origin, whereas the lakes have a glacial origin, resulting from dammed moraine sediments. The significanceof this work lies in demonstrating how geomorphological research can be employed to provide a detailed understanding of the pattern of lake depressions.

Progress in Arctic coastal geomorphological research in times of rapid climate warming

Recognising the degree of climate transformations in the Arctic becomes vital, especially in times of rapid global climate change. The 21st century has seen a renaissance in Arctic coastal research. Here, we aim to present this recent progress. Moving from the European Arctic through the Siberian part and ending with the Canadian Arctic Archipelago (CAA), we describe how the region’s coasts have transformed. This work is mostly focussed on progress in coastal geomorphology, geohazards, and reconstructions of the paleoarchives, although we also address the future research challenges of cold region coastal environments.

An Overview of Geomorphological Mapping: A Case Study of Rimbi Chhu River Basin, Sikkim, India

Geomorphology is the primary science which demonstrates the basic understanding and mapping of terrain features. A geomorphological map consists of scientific data and dynamic source of information on characteristics of landforms, their origin and evolution, which can be recorded in a map form. Basin hydrology also gets impacted by the terrain features of a basin as overland flow, stream flow and through flow is largely determined by the underneath surface. The configuration of the basin topography reflects the nature of the interaction between process and form. Profound understanding and in depth analysis of geomorphological features of a river basin can provide beneficial information for predicting, preventing and mitigating natural hazards; managing natural resources sustainably for future generation. Implementation of remote sensing and GIS techniques have fostered incredible improvements in landform recognition and accelerated the growth of geomorphological research. The river Rimbi Chhu has been selected as the study area in order to determine terrain configuration in relation with geomorphological features of the basin area. Visual representation of terrain (such as aspect, slope, channel networks, different river profiles, shaded relief and flow direction) and geomorphological (saddle, ridge line, convex-concave slope, rounded hills, fault for instance) derivatives is therefore illustrated, as well as a description of the challenges and crisis that can occur in this context.

Identifying geomorphic domains using hierarchically clustered drainage area‐slope scaling

AbstractArea‐slope scaling is an important tool for analysing geomorphic processes. In this study, we used hierarchical clustering to sort the area‐slope scaling data for both the numerical landscape created using the LandLab model and real landscapes. Random forest analysis was used to explore the effect of hierarchical clustering. We aimed to illustrate the heterogeneous features of area‐slope clustering and their influencing factors and to test whether they can be used to distinguish geomorphic domains. Our results showed that hierarchical clustering can easily detect the heterogeneous features of area‐slope scaling constrained by tectonic uplift and fluvial erodibility but not those constrained by the diffusion coefficient. The slope gradients over the inflection/transition zone of the colluvial and fluvial domains play a key role in identifying area‐slope scaling from different geomorphic domains. Case studies show that area‐slope scaling of clusters would be affected by different lithology and distance away from the trunk channel. In the high erosion circumstance, the fluvial process caused by tectonics leads to increasing slope gradients over whole geomorphic domains, as well as to retreating inflection between the colluvial and fluvial process domains. In low erosion circumstances or steady state, the fluvial process caused by nearby rivers cannot effectively change the slope gradients but can retreat the inflection. The real landscapes suggest that basins should be carefully selected for area‐slope scaling analysis to ensure that they are representative of the entire study area. Before geomorphological research, more basins of a specific research region need to be selected to conduct hierarchical clustering to select representative basins. Our study could be helpful in the identification of area‐slope domains, the extraction of geomorphic metrics and geomorphic process research.

Editorial 2024: Large language models, artificial intelligence and geomorphology

AbstractLarge language models (LLMs), such as ChatGPT, have seen an explosion of interest over the last 12 months. It is hard to see an area of education and research where we are not having to face the challenge they pose, a form of artificial intelligence (AI) that is capable of generating text in response to relatively minimum prompting. The text generated can be surprisingly convincing. We now have definitive evidence of work being submitted to Earth Surface Processes and Landforms (ESPL) that has made use of LLMs. As a result, the Editorial Board has recently developed its policy on the use of LLMs in authoring, reviewing and editing papers. In developing our policy, we have taken note that through the journal's publisher Wiley, we are a signatory to the Committee on Publication Ethics (COPE, https://publicationethics.org/). COPE provides us with a framework within which our policy sits, one that given the speed with which LLMs are developing means that it will not be definitive and will surely need to be revisited over the not‐too‐distant future. This extended editorial explains our policy, specifies guidelines for authors, reviewers and editors and also reflects more generally on the positive opportunities and challenges that emerging forms of AI pose to our community and our stated goal of publishing research in geomorphology that is of the highest quality.

Twenty-five years of hydromorphological restoration in the high-energy, gravel-bed rivers of southern France: What are the current benefits for bedload dynamics and sediment balance in the left-bank tributaries of the Aude River within the Minervois region?

The article synthesizes 25 years of hydromorphological restoration in the high-energy, gravel-bed rivers of southern France. In the Minervois region, the authors highlight the challenges and advancements made in riverbed restoration following the catastrophic flood of November 1999. This event catalyzed research in fluvial geomorphology and led to significant restoration initiatives implemented by the SMMAR. The article pays particular attention to the role of floods and ordinary flow events in the hydromorphological functioning of the channels, specifically focusing on hydraulic geometry, channel pattern, bedload transport, and sediment balance. The methods developed rely on field observations and measurements, as well as image processing. Between 2012 and 2024, the transport distances of cobbles were monitored in the watersheds using RFID technology (passive and active microchips). From 2016 to 2021, sediment balances of the restored river sections were quantified through LiDAR surveys to better understand how rivers respond to the new flow conditions and channel morphology resulting from restoration efforts. The results indicate that the restored sections function as preferential sediment storage areas. Although the restoration has improved sediment transport conditions during floods, several tributaries do not contribute sufficiently to the sediment recharge of the main channels, leading to chronic sediment deficits. The data also emphasize the importance of ordinary flows in sediment transport, which can often result in riverbed incision. To achieve a more balanced sediment supply, the authors advocate for the reactivation of sediment sources at the watershed scale.

Anthropogenic Geomorphological Mapping of The Central Sector of João Pessoa Metropolitan Region, Brazil

This work consists of the application of a new geomorphological mapping methodology with a focus on anthropogenic landforms. The study area is the central sector of the metropolitan region of Joao Pessoa, where densely urbanized areas and rural areas are found, but with high human intervention. The geomorphological mapping methodology proposed in this work was developed from Brazilian, English, and Italian experiences and included extensive field trips. The result was quite satisfactory where the final map represents from the present geological foundation (morphostructure) to the current anthropogenic landforms. A broad and integrated legend representing all mapped taxa was also proposed. The geomorphological map produced, in addition to being a synthesis of the geomorphological research carried out, is an important tool for urban and environmental planning.

3d model of Medova cave, Lviv

The purpose of this article is to present and provide a detailed analysis of the 3D model of the Medova Cave in Lviv, created using laser scanning technology. The main objectives include revealing the accuracy and detailing the obtained model, as well as determining its potential applications in various fields such as geological research, scientific exploration, cultural heritage, and tourism. Additionally, the article aims to emphasize the importance and advantages of using laser scanning for creating precise and realistic 3D cave models, opening new possibilities for the study and preservation of natural unique formations. Method. The article describes the methodology used to create a 3D model of the Medova Cave, which involves several key steps. Firstly, a thorough reconnaissance of the cave is conducted to identify technical and logistical aspects such as temperature, humidity, movement restrictions, and lighting that are necessary for the scan. Next, ground-based laser scanning is employed, proving effective in conditions of complete darkness and limited space, to ensure accurate data collection regarding the cave's geometry. Reflective markers are strategically placed inside the cave before scanning, facilitating efficient scanning and alignment of scans. Specialized equipment such as GNSS receivers (Trimble R7) and ground-based laser scanners (Faro Focus 3D 120) are utilized for data collection. Software tools like Faro Scene are used for stitching together scans into a unified 3D point cloud model during data processing. Finally, the accuracy of marker connections is analyzed to ensure high-quality registration, and the 3D model is constructed. Detailed 3D models, including textured models and cross-sections for visualizing the internal structure of the cave, were constructed using software such as Move. Results. The research on the Medova Cave, employing ground-based laser scanning, yielded an accurate and detailed 3D model of the cave. This model opens new perspectives for geological and geomorphological studies, tourism development, and cultural heritage preservation. The use of advanced scanning technologies allowed for a comprehensive representation of the cave's geometric features, considering its complex structure and varied dimensions. Scientific novelty and practical significance. The creation of the 3D model of the Medova cave using laser scanning signifies progress in cave geometry studies. The innovation lies in the utilization of advanced laser scanning technologies to ensure a detailed representation of the cave's geometric features, accounting for its complex structure and diverse dimensions. The novelty also lies in the development of a data collection and processing strategy in conditions of complete darkness and limited cave space, resulting in an accurate and realistic 3D model. Practically, the 3D model of the Medova Cave serves as a crucial tool for geological and geomorphological research and the exploration of unique natural formations. The model opens new opportunities for tourism development, where virtual cave exploration can provide a unique experience for visitors. Creating this 3D model is a significant step in preserving and documenting cultural heritage, contributing to the scientific and cultural development of the region, and providing access to unique objects for researchers and the public.

Quantifying dune migration patterns and influencing factors in the central Sahara Desert

Based on Landsat images and ERA5 climate data, here we analyzed geomorphic dune patterns and the spatial characteristics of dune migration in the central Sahara Desert region (SW Libya, SE Algeria), using the COSI-Corr technique. Our results revealed clear observable drift potential (DP) and resultant drift potential (RDP) gradients, these decreasing from a northerly to southerly direction. Moreover, the annual average RDP/DP in most areas was <0.3 (i.e., highly variable). The main dune types in the study area included complex transverse ridges (22.82 %), linear dunes (19.87 %), barchan and barchanoid chains (16.95 %), and star dunes (13.55 %). Of these, barchans and barchanoid chains, as well as complex transverse ridges, appeared in areas of relatively high DP, while complex longitudinal ridges and honeycomb dunes were found in those of low DP. Linear dunes had a simpler wind composition, being mainly distributed in areas with intermediate wind variability. Both the honeycomb dunes and complex longitudinal ridges had nearly always formed in complex multi-directional wind environments. Dune migration displacement in dune fields ranged widely, from 0.5 to 23.57 m (mean = 6.71 m), during the 30-year study period (1993–2022). Barchans and barchanoid chains migrated fastest, with a mean value > 10 m/yr; in contrast, complex longitudinal ridges and honeycomb dunes had the slowest migration rate, always at < 5 m/yr. Overall, the dune migration rate was mainly related to dune height and wind regime. Spatially, the dune migration trend was basically consistent with that of the resultant drift direction (RDD), mainly in a northwesterly direction (28.36 %). The accuracy testing results indicated that the COSI-Corr displacement measurement accuracy was generally higher than the dune migration direction accuracy. This study provides not only valuable reference data for regional aeolian activities, but also insight into the developmental environments and migration dynamics of differing dune types, which could be used for prospective regional aeolian geomorphology research in the Sahara Desert.

Emmanuel de Martonne's glacial geomorphology research in Parâng Massif (the Southern Carpathians)

We are publishing this article in 2023, the year when the 150th anniversary of the birth of the French geographer is celebrated, the article being a tribute to Emmanuel de Martonne's work in Romania, especially for his contribution to the research of the Transylvanian Alps (the Southern Carpathians). Of the two doctoral theses that the French geographer elaborated on the territory of Romania, the last one, defended in 1905 and published in 1907 at the Sorbonne University in Paris, was dedicated to the geomorphological evolution of the Transylvanian Alps (the Southern Carpathians). Of the 14 field campaigns that Emmanuel de Martonne carried out in Romania, eight were carried out in the Southern Carpathians (Banat Massif, Transylvanian Massif) and in the neighboring regions closely related in their paleogeographical evolution to the Transylvanian Alps (the Subcarpathian area of Oltenia, the Subcarpathian area of Muntenia, and Mehedinți Plateau). For the French geographer, the transverse valleys of the Southern Carpathians were examples indicating the extensive tectonic movements that affected the territory of Romania in the Paleogene and Neogene. Glacial influences and relief forms in the high part of the Southern Carpathians became the main concern of the French geographer for at least a decade of research in Romania. More obviously, in some parts of the Southern Carpathians, the action of glaciation cut out specific shapes within the platform of the high peaks (Borăscu planation platform). In the research in Parâng Mountains, Emmanuel de Martonne aimed to identify some key evidence of glaciation: glacial cirques, lakes, valleys, thresholds, glacial grooves, glaciated knobs, and moraines. Above all, the French geographer believed that the general topography of the valleys and cirques is the fundamental element that certifies glaciation and the presence of lateral cirques justifies the succession of glacial periods.