bluuebunny/crossref_metadata_2025 huggingface dataset:
Drainage rearrangements in a semi-arid area: a case study on the Brazilian northern passive margin
Authors: Rodrigues Wesley , Salgado André
Published: June 2022

In the last decades, there has been progress in understanding the importance of tectonic activity and climatic oscillations for the relief evolution of semi-arid regions. However, little is known about the role of drainage rearrangements in the morphogenesis of semi-arid areas. The semiarid region of Brazil, particularly in its northern passive margin, exemplifies this lack of studies. The configuration of the drainage network in the region is interpreted as a passive inheritance, given by superimpositions on Precambrian structures reactivated during the opening of the Equatorial Atlantic Ocean in the Cretaceous. Thus, this research aims to understand the current hydrographic configuration of the northern Brazilian semi-arid region, investigating geological and geomorphological evidence of possible fluvial reorganisations. Those evidences were identified on a regional scale, from the analysis of diagnostic morphologies of drainage rearrangements (e.g. capture elbows, anomalous drainage patterns, low divides and dammed river deposits) in geological maps and in data extracted from remote sensing (e.g. MDE SRTM 1 arc-second). Among the results, the following stand out: (i) dense drainage network formed by parallel exorheic rivers, in which only two very asymmetrical catchments – Jaguaribe and Piranhas-Açú – comprise about 73% of the regional flow; (ii) transverse tributaries marked by gorges that break the regional structural fabric; (iii) 4th order (or higher) river channels with sudden inflexions and reversals, especially orthogonal elbows, generally close to flattened divider sectors; (iv) concentric drainage patterns coincident with areas of natural damming of Neogene fluvial deposits, and areas with inactive pediment levels and; (v) surface dissection levels with differences of about 200 m high, with transitions limited by Precambrian structures reactivated during the Neogene-Quaternary. This evidence suggests that the region's drainage network has undergone recent and complex reorganisations, with fluvial incorporations carried out by the Jaguaribe and Piranhas-Açú catchments, probably on endorheic systems. The apparent expansion of the Jaguaribe and Piranhas-Açu catchments indicates that these rivers had their erosive power increased to the detriment of adjacent rivers, reordering regional watersheds through captures and overflows. This fact indicates that drainage rearrangement processes in semi-arid areas may have been more complex than previously thought and show the need for more research on the topic.
Flood events as geomorphic thresholds for river channel change 
Authors: Dumitriu Dan
Published: June 2022

 

Flood events as geomorphic thresholds for river channel change

Dan Dumitriu

“Al.I.Cuza” University of Iaşi, Faculty of Geography and Geology, Department of Geography, Carol I Bd, no 20A,Iaşi, 700505-RO, Romania

E-mail address: dndumitriu@yahoo.com

 

Abstract: River channel are highly dynamic in time and across space, constantly adjusting under the influence of natural and anthropogenic controls. The aim of this study was to assess the role of flood events recorded between 1994 and 2020 in the Trotuș River (Eastern Carpathians) channel changes. The response of the channel to these floods consisted of discontinuous spatial adjustments in the channel width and channel bed elevation. The assessment of the channel aggradation/degradation rates was performed based on the evolution over time of average multiannual discharge levels and channel survey data (cross-sections). Prominent changes in the channel occurred in the Târgu Ocna–Căiuţi sector (30 km long, nearly 20% of the entire length of the river), where, between 1994 and 2020, the channel planform have widened significantly and channel bed deepened by an average value of 1.15 m (2.2 cm y-1). In terms of their geomorphic impact, the 2005, 2010 and 2016 flood events can be considered severe floods, even catastrophic in certain sectors. The recovery time for changes triggered by major flood events ranged between one and nearly 10 years, whereas in the case of shifts generated by high frequency, low magnitude events, the recovery time was maximum one year. Over short term flood events drive the direction and intensity of channel bed elevation adjustments.

Keywords: Flood; channel bed level change; channel planform change;  recovery time; geomorphic impact
Dynamics of the “La Vueltona” in Picos de Europa (Spain) debris cones during the period 2009-2018.
Authors: de Sanjosé Blasco José Juan , Serrano Cañadas Enrique , López González Mariló , Alonso Pérez Estrella , Gómez Gutiérrez Alvaro
Published: June 2022

Debris cones represent a typical landform in temperate high mountain regions. These features show representative periglacial and nival processes in the frame of a dynamic equilibrium. In this work, two debris cones (ahead A and B) located in the “La Vueltona” study area in the Picos de Europa mountain range (N Spain) are analysed. The dynamics of these landforms was studied for a period of 10 years (2009-2018) by means of Digital Elevation Models (DEM) surveyed using a Terrestrial Laser Scanner (TLS). We used the steepest slope line (SSL calculated in the 2009 DEM) to understand the lineal dynamics of the studied debris cones for the whole period. Statistical methods based on multivariate data were used to model the altitude of every location along the SSL for the year 2018. These statistical models used as input the topographic data from 2009 to 2017. The modelled and surveyed altitude for the year 2018 were compared, showing a coherent performance of the modelling approach, with errors within the typical uncertainty of the surveying technique. The Vueltona debris cones showed a wavy dynamics along the SSL, which may be useful to predict their evolution in the short-term. The dynamics model could be extrapolated to other debris cones in temperate high mountain areas.
Spatial scaling in geomorphology: Extrapolating micro-erosion measurements to the landform scale on shore platforms using unoccupied aerial vehicles
Authors: Yuan Runjie , Kennedy David , Ierodiaconou Daniel
Published: June 2022

Downwearing rates of shore platform have been quantified with a number of ground-based techniques (such as the micro-erosion meter (MEM)), providing knowledge of the evolution of coastal landforms. However, it remains problematic to extrapolate the micro erosion results to the landform scale. This is because only a very small proportion of the platform is monitored and usually biased to flat rock surfaces. In this study, we used the shore platforms in south-eastern Australia, which has the world’s longest continual erosion records, as an example to solve the fundamental question on result extrapolation across spatial scales. Surveying using an unoccupied aerial vehicle (UAV) – post-processing kinematic (PPK) – structure-from-motion (SfM) workflow, indicates the shore platforms at Marengo and Jump Rock having similar morphology. The generated mm-scale dataset was used to contextualize 4 and 12 MEM sites into the orthomosaics and digital surface models (DSMs) at each location. By using two different methods, we assessed how these monitored surfaces were representative of the morphology of the entire platform. On average, the 4 MEM sites represented 52.2% of platform surfaces at Marengo and 73.2% with the 12 MEM sites at Jump Rock. To improve the representativeness of sampled surfaces, it was found that 20 randomly sampled MEM-size (4.33 × 10-3 m2) surfaces could well represent (c. 90%) the landform morphology at the scale of 104 m2. The representativeness was only slightly improved by upscaling the surface size from original cm2, to dm2 (0.16 m2) and m2 (1 m2) scales, implying the importance of sample number over sample size. Using the cm-scale dataset covering a larger geographic region, a bias of MEM installation was found with all 43 MEM sites concentrated at the fast-eroding upper intertidal zone. An elevation-weighted erosion rate of 0.21 mm/yr was calculated, lower than the original mean of 0.25 mm/yr provided by the MEM network. Moreover, a spatial pattern of rock surface morphology was observed across the platform with higher slope and roughness at the seaward end, suggesting more intensive wave processes and varying weathering agents compared to those surfaces further inland.
Empirical rainfall thresholds for the triggering of landslides in northern Portugal and Spain: a preliminary overview
Authors: Valenzuela Pablo , Vaz Teresa , Domínguez-Cuesta María José , Pereira Susana , Zêzere José Luís , Rivas Victoria , Remondo Juan , Bonachea Jaime , González-Díez Alberto , Bornaetxea Txomin , Sánchez-Espeso Javier , San Millán Eliezer , Francos Lucía
Published: June 2022

Landslides, common and widespread phenomena in the north of the Iberian Peninsula, represent a relevant cause of geomorphological hazard, in particular in some mountainous and densely populated areas of Portugal and Spain. Rainfall is the most relevant landslide-triggering factor in these territories within the Iberian Atlantic Arc, characterized by an Oceanic climate with some areas of Mediterranean influence and average annual precipitation in the range 900-1900 mm.

Since the 1980s, several research groups have been developing work lines focused on the study of the temporal occurrence of landslides and its relationship with different precipitation patterns by calculating empirical rainfall thresholds. Their computation is mainly based on the statistical analysis of individual or multiple rainfall events which caused landslides in the past. A wide variety of approaches considering different data sets, methodologies and spatio-temporal scales have been conducted. However, some results have not been greatly disseminated or have remained unpublished, hampering the overall analysis of research carried out up to date.

The present work aims to review the literature related to empirical rainfall thresholds in the north and northwest of the Iberian Peninsula with the objectives of (i) synthesizing existing data, (ii) establishing comparison criteria that consider the different characteristics of each study area, data set, and methodology used, and (iii) addressing a joint analysis. The study zones are located the north of Portugal (Oporto, Vila Real-Douro Valley and Casal Soeiro areas) and in the north of Spain (Asturias, Cantabria and Guipuzcoa and Vizcaya provinces within the Basque Country).

The review revealed that over 80 landslide rainfall thresholds have been compiled, most of them defined through equations. To describe the critical rainfall-triggering conditions, 75% of the thresholds considered the accumulated precipitation during a specific period, while the remaining 25% considered the precipitation intensity. Critical accumulated rainfall in 24 hours showed appreciable variations in the range 20-140 mm in Spain and 20-80 mm in Portugal. Almost 70% of the thresholds showed regional representativeness; the remaining rest showed local representativeness.
Geomorphological approach to flash flood hazard and vulnerability evaluation in torrential basin-fan systems in Campania (South Italy)
Authors: Forte Giovanni , De Falco Melania , Santangelo Nicoletta , Santo Antonio
Published: June 2022

A flash flood is a very quick increase in the discharge of a stream, generally caused by short duration and high intensity rainfalls. This phenomenon is very frequent in Europe and in Italy too, where generally occurs in small catchments with short response time, causing many damages in the outlet zones. In historical times, numerous flash flood events occurred in Campania Region (Southern Italy), with an increase in frequency in the last decades, associated with the present trend of climate change. 
This note summarizes the results of the last ten years studies on the flood events occurred in the torrential basin-fan systems of the Campania region, aiming to contribute to the assessment of the hazard and risk condition. In these watersheds flash flood events resulted in a series of phenomena, passing from debris flow to debris flood and water flood, which produced serious damage to urban centers and cultivated areas. Unfortunately, these catchments are often not monitored and the lack of information on rainfall and flow data makes more difficult to apply hydrological and hydraulic models to evaluate hazard and risk. Hence, in these settings, geomorphological study and post-event field campaign have been useful to identify the flooding prone areas and the magnitude of the occurred events. The latter has been achieved by the estimate of the maximum water heights of the flow, of the thickness of eroded and/or deposited material and of the relative particle size of the deposits and finally of the volumes. The acquisition of remotely sensed images by means of UAV (drones) enhanced the field surveys to obtain these data. More in detail, the integration of morphometric analysis in GIS, with field and remotely sensed data permitted to draw several thematic maps, that together with the identification of the damage states have been exploited to produce empirical vulnerability curves for these events. 
Collecting such data represents a fundamental issue for calibrating hydraulic flow models for the hazard evaluation, while the development of vulnerability tools can be adopted to assess the risk and define the best mitigation strategies.

 
Long-term impacts of hydropower plants on the sedimentology and morphology of the Warche riverbed (Belgium)
Authors: Fraudin Camille , Mercier Eva , Petit François , Houbrechts Geoffrey
Published: June 2022

Significant hydrological and morphological changes occur with the construction of hydropower plants. The main modifications are related to changes in the hydrological regime and disturbances of the sediment continuity.

This study is based on the Warche River in the northern Ardennes (Belgium), on a 7 km stretch downstream of the Bütgenbach dam built in 1932. During the winter months, the hydroelectric power plants release a flow of 10m³/s almost every day, which corresponds to the morphogenic flow (0.6 bankfull discharge).

A study carried out in the 1990s (Assani and Petit, 1997) showed that, following the construction of the Bütgenbach dam, a general incision of the entire 7 km stretch took place in about 30 years, followed by a doubling of the channel width. Other changes such as a reduction in the number of rifﬂes and pools, an increase in the number of gravel banks and islands and an increase in rock outcrops in the channel have also taken place.

In our study, the question is to quantify the rate of propagation of this incision. For this purpose, RFID tags implanted in pebbles were used. As the morphogenic discharge is reached almost daily, surveys were conducted directly in the days following the deployment of the PIT tags. In a second step, more spaced surveys were also carried out according to the hydrological events.

A second part of our study consists of analysing the morphological evolution since the 1990s by comparing past surveys with the topographic data of 2022. Thanks to these data, we can observe whether a new morphological equilibrium has been reached or whether the canal continues to widen.
Deep-seated gravitational slope deformation and rock-slope failures deposits in Iceland: inventory, dating and role in landscape evolution
Authors: Mercier Denis , Portier Emilie , Decaulne Armelle , Cossart Etienne
Published: June 2022

Following the Last Glacial Maximum, icelandic hillslopes experienced a paraglacial crisis, which occurred between 15-10 ka BP. In the North, West and East parts of Iceland, in the high plateaus and slopes developed in the Tertiary basaltic formations, two types of paraglacial denudation features, deep-seated gravitational slope deformation (DSGSD) and rock-slope failure (RSF) deposits, are numerous.

An inventory and several maps of DSGSD and RSF are proposed at the scale of those three icelandic regions of Iceland. The mapping was made by combining aerial photographs, satellite images and field prospections. The DSGSD is characterized by typical ridge-top grabens, scarps and antiscarps associated with upslope and downslope dipping fractures along bulged upper slopes. The RSF could be identified by defining the crown and deposits. Both features could be analyzed by using direct observations and NDVI index from satellite images.

An approach of the timing of the DSGSD and rock-slope failures settlement is also proposed in this contribution by using field investigations (geomorphological stacking, tephrochronology, radiocarbon dating of wood remains in depression on RSL deposits, and age-depth models). The genetic links between DSGSD and landslides, the effects of these paraglacial denudation dynamics on the evolution of landforms (cirques, valleys) are discussed. Furthermore, the erosion rates involved by such paraglacial crises (volumes of landslide deposits) are compared with erosion rates involved other processes on icelandic slopes during the Holocene.

Finally, this paraglacial denudation crisis, illustrated by DSGSD and RSF, appears as the main sequence of icelandic landscape evolution since the last glaciation.
Digital geomorphological mapping with GOGIRA (Ground Operative-system for GIS Input Raw-data Acquisition) – An innovative system to numerical cartography.
Authors: Licata Michele Camillo Gabriele , Bonasera Mauro , Buleo Tebar Victor , Fubelli Giandomenico , Taboni Battista
Published: June 2022

In recent years, digital mapping systems have gained interest among geomorphologists thanks to the fast evolution of technology. However, a mapmaker still uses traditional cartographic supports as printed topographic maps, which need to be   subsequently digitalized. Every step adds an additional level of cartographic error, often difficult to quantify. A solution can be to map the landforms directly in digital format during the fieldwork through an ad hoc system.

With the purpose of making a “native” numerical cartography, GOGIRA (Ground Operative-system for GIS Input Row-data Acquisition) has been realized. GOGIRA consists of a set of hardware and software tools to digitalize real-world geomorphological elements and obtain georeferenced shapefiles. It is currently composed by two devices for data acquisition: an Android App for data collection and a Python-based software for coordinate computation. The technologies have been chosen to be enough accurate but cheaper than already available topographic tools. Each device uses an “Arduino Nano” board and low expensive sensors like MPU6000 (3 axis accelerometer + 3 axis gyroscope) or BNO055 (3 axis accelerometer + 3 axis gyroscope + 3 axis magnetometer).

GOGIRA has been tested in Aosta and Tanaro Valley, in North-Western Alps of Piedmont Region (Italy). The first case study was chosen in the context of the active monitoring of a complex landslide system close to an important highway that connects Italy, France and Swiss. It was possible to remotely (distance from 0.5 to 2.7 km from targets) map an area of limited access due to steep slopes, high scarps and rockfall hazard. Small single elements were mapped, as rockfall scarps not detectable from topographic support. The time for the survey has revealed to be short (a couple of hours included the search of a good observation point). The second case study was picked during the preliminary fieldwork for the realization of rolling tanks to mitigate the hydrologic hazard in the anthropized Tanaro Plain. The area has been investigated both with traditional methods and GOGIRA system, if morphometry allowed. Scarps, karst springs and debris/rock flow tracks were mapped.

The results obtained from both the tests highlight complications in mapping polygonal elements regarding visibility and overlaying but show a particularly high reliability in collecting data on linear and punctual geomorphic elements.
River adjustment to low-medium rainfall events because of wildfires in highly weathered landscapes
Authors: Gomez-Heras Miguel , Ortega-Becerril José Antonio , Garrote Julio , Vázquez-Tarrío Daniel
Published: June 2022

Wildfires are increasingly frequent events which lead to rock weathering, soil erosion and post-fire colluvial-fluvial sediment dispersal in Mediterranean environments. Weathering-erosion balances are typically disturbed at the catchment scale, as well as source-to-sink sediment routing after a wildfire. This is a particularly relevant effect in areas highly weathered prior to wildfires.

A wildfire occurred in August 2021 affected an area of 220 km2 of eastern Gredos mountain range (Avila, Spain). A systematic series of diachronic pictures in approx. 30 sites were taken after every post-fire storm event. Major changes were observed following a sequence of small to moderate rainfall events occurring immediately after the wildfire. First, ashes filled completely small dams. After, sand bars formed, and several debris flow events occurred at the center of the storms.  Most of the tributaries were affected by waves of sediment/erosion showing various levels of damage depending on the distance to the storm center, the slope and degree of coverage.  However, certain parts of the area remain in a metastable condition and will probably experience new adjustments after the next major rain events. Sediment production and dispersal has been higher than expected for small to medium rainfall events. This suggests a high sediment supply to channels from mass wasting processes, probably due to the wildfire leaving slopes prone to erosion. The area affected by the fire includes 35 regionally and nationally listed Cultural Heritage sites that were affected both by the wildfire, extinguishing actions and posterior river response. Particularly, a series of pre-Roman sites were affected and there is a still-unknown number of cultural heritage sites that may be affected by post-fire sedimentation. Noteworthy, a 200-year-old bridge was destroyed by floods, which may suggest either an increase of the return period of floods or an anomalous behaviour of the basin.

Theoretical hyetographs and peak flows for a situation pre- and post-fire were obtained by means of sediment sampling, soil infiltration analysis and hydrological models of a series of real rainfall events we obtained. These results can then be fed into hydraulic models to analyze variations in the energetic flow conditions and its erosive capacity. Hydrodynamic results were calibrated by analyzing sediment size deposits (fluvial palaeocompetence analysis). This is especially relevant for land use management due to the increased probability of co-occurrence of high intensity fire and post-fire rainfall episodes.

This research was funded by Top Heritage (P2018/NMT-4372) programme from the Regional Government of Madrid (Spain) and Grants PIC2020-116896RB-C21”, “PIC2020-116896RB-C22” funded by MCIN/AEI/ 10.13039/501100011033.
An appraisal of Pre- and Post-failure regimes of a hillslope using stability, runout, and structural implications; A case study from the NW Himalaya
Authors: Jamir Imlirenla , Kumar Vipin , Kumar Ojha Arun , Gupta Vikram
Published: June 2022

The Himalayan Mountain range is infested by natural disasters annually. Mass movement and hillslope instability are among the most common phenomenon witnessed in those regions. The propensity to such activities is perplexing since it is not attributed to a definitive factor. The reason being the complex geological condition of this mountain range, topography, aided by anthropogenic intervention. A number of landslides reported in these regions are often rainfall induced landslides. However, there is always an interplay of geomorphology and tectonics which contribute to such mass movement.

On September, 2017, a colossal landslide occurred along the char Dham (Hindu pilgrimage) corridor, located near Wazri (locally called Ojari) village in Uttarakhand (India). Resulting in the blockade of road for four consecutive days and stranding ~1313 pilgrims of the Char Dham Yatra, and as many as 14 villages were cut-off from the main district headquarters. In order to evaluate the landslide, slope stability, runout, structural, and precipitation analysis were carried out for both the pre- and post- failure event. In the pre-failure analysis, results showed that the maximum shear strain of about 0.16-0.26 was developed parallel to the slope and a total displacement of about 1.8-8 m was likely to take place, parallel to the slope. In the post-failure analysis, results indicated that the maximum shear strain had decreased to 0.14, with a decrease in total displacement to 4.4m. Indicating that much strain was still accumulated in the existing slope. This still implied that the slope was unstable and had accumulated much load on the slope, with high chance of further failure. This model was testified by the incident in the consecutive year of July 11, 2018, where the landslide was triggered due to incessant rainfall. Resulting in the disruption of the daily traffic and stranding ~90 pilgrims of the Char Dham Yatra. The debris flow simulation of the loose unconsolidated material, in case of excessive rainfall effect, revealed a flow accommodating 7-24 m height, 3-4 m/sec velocity, and 100-800 kPa pressure along the Yamuna River. To analyze the role of deformation in the landslide, the study area was subdivided into three distinct zones; (i) fault core, (ii) fault damage zone, and (iii) the intact zone (undeformed host rock), following the evidence from fields. From the visual observations, it was evident that the landslide was confined to the Main Central Thrust (MCT) damage zone.
Geomorphological mapping as an instrument for Geoheritage and Geoconservation - a study of geosites in granite terrains of Northeastern Brazil
Authors: Leite Meira Gomes Eliomara , Pinheiro Maia Rubson , Vidal de Souza Anna Sabrina , da Silva Barbosa Ana Beatriz
Published: June 2022

Geoconservation is an instrument of Geodiversity, and encompasses a set of actions from inventorying and characterization of geosites to their conservation and management, in addition to enabling the appropriate use of its scientific, educational, cultural, touristic, and economic values. The inventory, characterization, and representation of geosites from a geopark is essential for recognition of its scientific importance and collaborates to verification of potential conservation and its different forms of use for geopatrimony. The geomorphological mapping as an instrument of this representation permits the users to visualize the landscape elements and makes them understand why such an area is a site and a geopatrimony. This work aims to describe the geomorphological heritage of an area designated for the creation of the Sertao Monunmental Geopark, in central Ceara, Northeastern Brazil, using geomorphological mapping, to represent the landforms and to discuss landscape dynamics.  In this regard, different cartographic products are necessary, such as geological maps, clinographic and hypsometric, pedological, hydrographic network and sub-basins, and geomorphological maps in detail and semi-detail scales in which the main geographic accidents, residual reliefs, planed surfaces, and slopes will be presented. The methodology of the landform classification will be made in accordance with Ross (1991; 1992), Santos et al. (2006), Dantas (2016), Diniz (2017), and IBGE (2009), among others that categorize the relief in taxonomic units. These are the following morphostructural units (1st taxon), morphosculptural units (2nd taxon), morphological units or similar patterns of forms (3rd taxon), types, and forms of relief (4th taxon). For the representation of relief patterns, it is assumed to consult the technical documents with standards and representations of geomorphological aspects. This work will be based, on geoprocessing techniques with GIS, mostly using QGIS software, and satellite and radar image processing for scales 1/250,000 and 1/100,000, and high-resolution imaging for more detailed scales (1/10,000 and 1/25,000). It is expected that this geomorphological mapping contributes to understanding the spatial setting of landforms in the study area providing an interpretation of the geomorphological facts and supporting different activities in the region, such as the orientation of visits and planning projects.
Submarine geomorphology of abrasion platforms off basalt sea cliff: based on multibeam bathymetry and SCUBA diving observations
Authors: Kan Hironobu , Kimura Hayate , Sano Wataru , Sannoh Masami
Published: June 2022

It is difficult to determine the sea floor geomorphology in the vicinity of the wave breaking zone on rocky shores. In this study, a multibeam bathymetric survey and SCUBA diving observations were conducted off a basalt sea cliff with vertical columnar joints at Keya, Fukuoka, Japan, to observe the geomorphology and environment of the abrasion platform in high resolution. The formation of abrasion platforms significant at the northern end of the cape, where the waves were concentrated. Two platforms were observed at depths of 12 m (13 m below mean sea level) and 17 m (18 m below mean sea level). The –12 m platform is covered by boulders of tens of centimeters to more than 1 m in diameter, and is formed by the erosion of the basalt sea cliff. These boulders may have been moved by storm waves and formed the –12 m platform by active abrasive erosion. On the landward area of the –17 m platform, sand and gravel are deposited between rounded boulders larger than 1 m in diameter. Scarce vegetation on the rounded boulders and sediments indicates that sediments may have been moved and displaced during storm surges. The seaward area of the –17 m platform also consists of large boulders with a diameter of 1 m or more, however, the numerous organisms attached to the surface of the boulders and rich biota around them implies that these boulders have remained stable for a long period of time. At depths greater than 20 m, the slope becomes smooth and gentle, with sand and silt. The absence of vegetation on the slope surface indicates that the sediments may move during storms. Considering the formation periods of the two abrasion platforms, the –12 m platform is considered to be a recent abrasion platform. In contrast, the –17 m platform is considered to be a relict landform of the abrasion platform that formed during the last interglacial period, owing to the gradual subduction trend of the study area. Assuming that the 104–107 m wide present abrasion platform (–12 m platform) eroded after about 8,300 years BP, when the postglacial sea level reached the present depth of approximately 10 m, the average retreat rate of the basalt sea cliff was estimated to be 1.25–1.3 cm/year.
Palaeoclimatic and morphodynamic implications from boulder dominated peri- and paraglacial landforms in two areas of South Norway 
Authors: Marr Philipp , Winkler Stefan , Löffler Jörg
Published: June 2022

Boulder-dominated landforms of periglacial, paraglacial and related origin constitute a valuable, but often unexplored source of palaeoclimatic and morphodynamic information. The timing of landform development initiation and its subsequent stabilization can be linked to past climatic conditions offering the potential to reconstruct cold climatic periods. In this study, Schmidt-hammer exposure-age dating (SHD) was applied to a variety of boulder-dominated landforms (e.g., sorted stripes and polygons, blockfield, paraglacial alluvial fan, rock-slope failure) in two different areas South Norway, Breheimen and Rondane. On the basis of old and young control points a regional SHD calibration curve was established and successively utilised for the calculation of surface exposure ages for individual landforms. The chronological investigation of development and stabilization of the respective landforms permitted an assessment of Holocene climate variability in different areas of South Norway and its impact on overall landform evolution. The obtained SHD ages range between 11.44 ± 1.22 to 3.45 ± 0.70 ka showing their relict character. There appear to be differences in the timing of stabilization of comparable landforms between the eastern and western part of South Norway within ca. 100 km. For instance, sorted ground structures show particular age differences and stabilized around 3 ka earlier in the eastern study area compared to the west. The sorted polygon ages in the west of 6.55 ± 0.68 and 4.76 ± 0.63 ka point to a stabilization around the Holocene Thermal Maximum (HTM; ~8.0–5.0 ka). In contrast, SHD ages from blockfields in both areas show rather young and comparable ages within the mid-Holocene, compared to former studies. Our obtained surface exposure ages from boulder-dominated landforms in two areas of South Norway give important insights into the local palaeoclimatic variability during the Holocene.
Towards a comprehensive overview of glaciation at the Alps-Dinarides junction: compilation of a GIS database and creation of a web map viewer
Authors: Gostinčar Petra , Žebre Manja , Jamšek Rupnik Petra , Mencin Gale Eva , Jež Jernej , Stepišnik Uroš , Atanackov Jure , Bavec Miloš
Published: June 2022

On a global scale, inventories and databases are gaining value and there is a demand for openly accessible and reusable data. Here presented GIS database of glacial geomorphological evidence is a compilation of all available glacial and other relevant data in the South-Eastern Alps and the Northern Dinaric Mountains in Slovenia, Italy and Croatia. The database contains the following elements: glacial landforms (e.g., moraines, cirques, erratic fields, kame terraces), non-glacial landforms relevant for the interpretation of the glacial environment (e.g., alluvial fans, alluvial terraces, rock glaciers, protalus ramparts, talus cones), outcrop locations, geochronological data, and data on geophysical exploration. The accompanying attribute tables contains some basic information for each feature, such as type and description of a landform, assumed age, reference, etc. In the first step of database creation, the data were digitised, georeferenced (if not already done by the authors themselves) and cited accordingly. In the second step, the input data were revised in the field and topographically adjusted using a high-resolution lidar-based digital elevation model. The GIS database of glacial geomorphological data was used to develop the web map viewer, which also displays empirically reconstructed ice limits for different time spans during the last glacial cycle (130-0 ka). The data stored in the GIS database is available as ESRI shapefile format. Both the GIS database and the map viewer are open access. Disseminating the results of past and ongoing studies on glacial geomorphological evidence in the Alps-Dinarides junction will improve the availability and accessibility of data, build on previous findings and potentially prevent unnecessary repetition of work already done. Improved accessibility of data also offers greater potential for further research in large-scale studies in the area.

 

This work was funded by the Past climate change and glaciation at the Alps-Dinarides junction project (J1-2479) supported by the Slovenian Research Agency.
The timing of formation of the Douro and Tejo rivers and implications for the evolution of the landscapes of central mainland Portugal
Authors: Binnie Steven , Neto de Carvalho Carlos , Cunha Pedro , Pereira Diamantino , Pereira Paulo , Dunai Tibor
Published: June 2022

The formation and development of major rivers limits the overall pace of the surrounding landscape evolution and drives sediment delivery from source to sink. The timings and rates of river incision may be a response to external influences, such as tectonic or climate driven base-level changes, or alternatively they may be linked to the breaching of internal thresholds, for example, drainage capture events. The Tejo and Douro rivers (also known as Tagus and Duero rivers) each drain a significant portion of the Iberian Peninsula and much of their courses through Portugal are typified by v-shaped valleys that are deeply incised into the surrounding topography. Earlier work has dated fluvial terrace deposits, mostly by luminescence techniques, but also by electron spin resonance and cosmogenic nuclide exposure dating. This has provided constraints on the late Pleistocene histories of the Tejo and Douro rivers, however, the timing of their transition from endorheic to exorheic is not precisely known and whether or not their histories are linked to a common mechanism is unclear.

This study aims to provide age constraints on the early history of the Tejo and Douro rivers, and to examine whether and to what degree the erosion rates of low relief, granite etchplain landscapes within the river’s catchment areas are responding to the trunk channel incision. We focus on reaches of the Tejo and Douro rivers located in the eastern sector of mainland Portugal. Samples were collected for cosmogenic nuclide (10Be and 26Al) surface exposure and burial dating to date upper fluvial terrace levels. In addition, a combination of cosmogenic nuclide exposure ages and depth profiles in bedrock outcrops, alongside basin-wide erosion rate determinations will be used constrain the pace of evolution of nearby granitic landscapes. Preparation of the samples for measurement is ongoing and we will present our initial findings.
Geostructural control in the rocky coast evolution: combination between UAVs and field survey techniques
Authors: Gomez-Pazo Alejandro , Perez-Alberti Augusto , Freitas Liliana , Chaminé Helder I.
Published: June 2022

Structural and lithological control has a key role in the shape of the rocky coast and its dynamics. Therefore, deepening the knowledge about these zones is one of the main aims for the future. In this sense, a granitic-gneissic sector was analyzed in the Galician coast (NW Iberian Peninsula) to understand their past and future evolution. For the characterization, we were used remote techniques based on data from UAVs (orthoimages and DEMs), just as hardness testers (Equotip and Schmidt-Hammer). The study was carried out at two scales, one general to analyze the main characteristics and select the interest sectors, and the other in detail applying the fieldwork survey techniques to explain the coastal landforms. This methodology allowed us to verify the correlation between remote and field data and improve our knowledge about the rocky coast dynamics by detecting and quantifying the topographical difference between closest sectors.
Assessing the Impacts of Lithology on Short-term Gully Evolution using the Very-high Resolution UAV Photogrammetry
Authors: Domazetović Fran , Šiljeg Ante , Marić Ivan , Cukrov Neven , Panđa Lovre
Published: June 2022

In this study we focus on the assessment of impacts of lithology on short-term gully evolution, with special emphasis on detection and quantification of one-year gully erosion induced spatio-temporal changes (STCs) within different lithological units. Study was implemented within the lithologically versatile wider area of gully Santiš (13 881.613 m2), located within the karst relief of the Pag Island (Croatia).

Repeat UAV photogrammetry was used for creation of very-high resolution (VHR) digital surface models (DSMs) of study area, where identical aerial surveys were carried on December 17th, 2019 and December 17th, 2020. Detection of gully erosion induced STCs was based on creation of digital elevation model of difference (DoD) from two created multi-temporal DSMs, using the Geomorphic change detection 7 software. Detailed lithological map (1:50) of whole study area was created through the comprehensive field lithological mapping, that was carried on September 16th, 2020.

In total nine different lithological units were mapped within the chosen karstic study area and VHR DoD with spatial resolution of 1 cm was created, allowing the detection of sub-decimeter STCs. Short-term gully evolution (2019-2020) resulted with the 13.46 m3 of eroded material, with very high variability of erosion intensity between certain lithological units. Highest erosion rates (6.80 m3) were detected within carbonate sandstones and sands, where gradual selective erosion has caused collapse of larger part of the more resistant sandstone. Significant erosion rates (4.84 m3) were also detected within Calcocambisol soil sediments, which were mainly caused by the mass wasting and gradual uphill retreat of the main gully headcut. Other seven mapped lithological units (e.g. limestone, quaternary breccia, talus, etc.) accounted for only 13% of all detected erosion (average erosion rate = 0.22 m3), thus confirming the lower erodibility to gully erosion of these more resistant units.

Carried study has confirmed that short-term gully evolution within specific karstic relief is highly affected by lithology, which directly controlls the intensity and distribution of erosion processes. Combined use of repeat UAV photogrammetry derived VHR DoD and detailed field lithological mapping has shown great potential for detection and monitoring of complex STCs and interpretation of short-term gully evolution. Due to that this methodology can be applied for monitoring of short-term geomorphic evolution in other lithologically complex areas.
Nature Conservation and Construction Projects in the Kras Region (Slovenia) 
Authors: Stupar Martina , Cernatič Gregorič Anica , Ličen Astrid
Published: June 2022

Slovenian region Kras, a low carbonate plateau located in the south-western part of Slovenia, represents a part of the Classical Karst area with numerous and diverse surface and underground geomorphological karst features, unique in their appearance and size. More than 1.500 known caves, and the numerous more to be discovered, furnish an extensive system of habitats for various representatives of subterranean fauna, including many endemic species. Equally important is carbonate surface that determines a great biodiversity of this area. Karst landscape has already been recognized as a unique natural and cultural heritage at the international level. The paper discusses the efficiency of integration of nature heritage and biodiversity conservation measures into the huge construction projects in the Kras region. Already built new motorways and current constructions of the new track of the Divača - Koper railway line and new logistic centre in Sežana town, intensively encroach on environmentally sensitive karst landscape and ecosystem. The national legislation in Slovenia has established a comprehensive framework for systematic protection of the environment and nature. A solid framework for systematic regulation of nature protection integrated into the spatial planning and sectorial planning is provided. The building permit issued on the sides of substantive nature conservation values determine nature protection conditions and obligations for the investor and contractors before, during construction and even after if necessary. Active cooperation is provided between the investor, contractors, and the professional service for nature conservation. The permitting process complies with national and European nature conservation legislation. The investor is obliged to ensure regular observation of protected areas, affected by construction works and the implementation of mitigation measures. Regular speleological and geological supervision in case new cartological or geological features appear during the construction is carried out in collaboration with the Karst Research Institute and Slovene geological Survey. Diverse specialists monitor flora, fauna and habitat types on construction sites before, during and after construction in order to detect the potential negative impact on which they propose new mitigation measures. The conference will highlight the effective integration of nature protection legislation and nature protection control in the field in large construction projects from their planning to construction, some examples of long-standing practice of the Institute of the Republic of Slovenia for Nature Conservation will be presented. 
The role of coastal defense structures and decreased fluvial sediment inputs in coastal erosion dynamics
Authors: Di Paola Gianluigi , Buccino Mariano , Ciccoaglione Margherita C. , Scorpio Vittoria , Rosskopf Carmen M.
Published: June 2022

Coastal erosion has extremely complex reasons and is related to both natural and anthropogenic factors. Sea level changes due to ongoing global climate change and/or soil subsidence are certainly among the most studied natural controlling factors. Nevertheless, anthropogenic causes are probably the most common ones. In fact, the coastal equilibrium is strongly conditioned by the reduction of sediment supply to the coast due to both direct and indirect anthropogenic interventions on river channels and catchments, and the construction of coastal defense and maritime structures, which interfere with the sediment transport towards and along the coast, and control sediment distribution.

In this study, the southern Molise coast, located along the central Adriatic coast and extending from the Termoli promontory to the Saccione River mouth, has been investigated. The analyzed coastline has been affected by intense erosion from the 1920s’ onwards, with the destruction first of the Biferno River delta, followed from the mid-1950s onwards by a more extensive retreat that produced an elevated loss of land during approximately the last 65 years. Shoreline retreat mainly affected the coastal segment including the Biferno River mouth, which is characterized by average annual rates of almost -3 m/y in the long-term, but also several other coastal stretches in different periods. To contrast further retreat, rigid coastal defense structures such as groins, adherent and detached breakwaters (both emerged and submerged) were realized over time. Nevertheless, during the last twenty years erosion further accelerated, with maximum annual rates recorded for periods 1998-2004 and 2011-2016, involving increasingly the coastal segments located south of the one that includes the Biferno mouth.

An accurate analysis of the mid to short term shoreline evolution, considering the possible role played by the decrease of sediment inputs from the Biferno River, meteomarine forcing and coastal defenses, has been carried out. Direct observations of shoreline variations over time and numerical simulations, performed with the "one-line" numerical model GENESIS, showed that the coast was governed by the wave component 10°N. In fact, the consequent equivalent direction of solid transport, coupled with to a net decrease in sediment inputs from the main rivers and its interference with coastal defenses, has contributed to increase coastal erosion rates, recorded in particular around the Biferno River mouth. Moreover, obtained results show that the bimodality of the wave climate may has significantly influenced the recent beach dynamics with the more inclined wave components (coming from the NW and SE sectors) would be responsible for the genesis of coastal instability which amplifies the erosion phenomena.