bluuebunny/crossref_metadata_2025 huggingface dataset:
PENERAPAN MODEL KOOPERATIF TIPE JIGSAW UNTUK MENINGKATKAN AKTIVITAS BELAJAR SISWA SMP KONSEP SISTEM EKSKRESI MANUSIA
Authors: FATIRANI HERNETA
Published: June 2022

This study aims to analyze the application of jigsaw-type cooperative learning models to improve student learning activities on the concept of human excretion systems. The subjects in this study were class VIII A students of SMPN 16 Hulu Sungai Tengah, totaling 23 people. Data on student learning activities can be known using observation sheets. The observation sheet contains the teacher's activities and student activities or activities during the continuous teaching and learning process. Data on student activity are analyzed descriptively based on the percent (percentage) scores achieved. The results showed an increase in learning activities which was shown by an increase in student activity in learning at each meeting experienced a significant increase. In the first cycle of meeting 1 the percentage of student activity obtained was 63% with the category "Quite active" and at meeting 2 the score increased to 68% but with a fixed category, namely "Quite Active". Meanwhile, in the second cycle of meetings 1 the percentage of student activity increased to 74% with the category "Active" and at meeting 2 to 81% with the fixed category "Active". So it can be concluded that the jigsaw-type cooperative learning model can increase student learning activities on the concept of a human excretion system.
ABSTRAKPenelitian ini bertujuan untuk menganalisa penerapan model pembelajaran kooperatif tipe jigsaw untuk meningkatkan aktifitas belajar siswa pada konsep sistem ekskresi manusia. Subjek pada penelitian ini adalah siswa kelas VIII A SMPN 16 Hulu Sungai Tengah yang berjumlah 23 orang. Data aktifitas belajar siswa dapat diketahui dengan menggunakan lembar observasi. Lembar observasi berisi kegiatan guru dan aktifitas atau kegiatan siswa selama proses belajar mengajar berlansung. Data tentang aktivitas siswa dianalisis secara deskriptif berdasarkan nilai persen (persentase) yang tercapai. Hasil penelitian menunjukkan adanya peningkatan aktifitas belajar yang ditunjukkan dengan adanya peningkatan aktivitas siswa dalam pembelajaran pada setiap pertemuan mengalami peningkatan yang cukup signifikan. Pada siklus I pertemuan 1 presentase aktivitas siswa yang didapat sebesar 63% dengan kategori “Cukup aktif” dan pada pertemuan 2 nilainya meningkat menjadi 68% namun dengan kategori tetap yaitu “Cukup Aktif”. Sedangkan pada siklus II pertemuan 1 presentase aktivitas siswa meningkat menjadi 74% dengan kategori “Aktif” dan pada pertemuan 2 menjadi 81% dengan kategori tetap “Aktif”. Sehingga dapat disimpulkan bahwa model pembelajaran kooperatif tipe jigsaw dapat meningkatkan aktifitas belajar siswa pada konsep sistem ekskresi manusia.
PENERAPAN METODE PEMBELAJARAN TUTOR SEBAYA UNTUK MENINGKATKAN KETRAMPILAN MENGOPERASIKAN ALAT DAN MESIN PRODUKSI PERTANIAN
Authors: DAHLAN MUH
Published: June 2022

This study aims to optimize students' skills in the Agricultural Machine Tools subject by applying the peer tutoring method for students in class X ATPH 1 SMK N 1 Nanggulan for the 2020/2021 academic year. This research is a Classroom Action Research conducted in two cycles. Each cycle goes through 4 stages, namely: planning, implementing, observing and reflecting. The research subjects were students of class X ATPH 1 SMK N 1 Nanggulan, totaling 36 students. The instruments used in this study were teacher observation sheets, student assessment sheets and documentation. The analysis used is descriptive quantitative data analysis in the form of percentages. Based on the results of the study, it was concluded that the application of the peer tutoring method could optimize skills in the Agricultural Machine Tool course for students of class X ATPH 1 SMK N 1 Nanggulan. The results of the research in Cycle 1 showed that students' skills were 66.7% and in cycle 2 increased to 91.67%.
ABSTRAKPenelitian ini bertujuan untuk mengoptimalkan ketrampilan siswa pada mata pelajaran Alat Mesin Pertanian dengan menerapkan metode tutor sebaya bagi siswa kelas X ATPH 1 SMK N 1 Nanggulan Tahun Pelajaran 2020/2021. Penelitian ini merupakan Penelitian Tindakan Kelas yang dilakukan dalam dua siklus. Setiap siklus melalui 4 tahapan yaitu : perencanaan, pelaksanaan, pengamatan dan refleksi. Subyek penelitian adalah siswa kelas X ATPH 1 SMK N 1 Nanggulan yang berjumlah 36 siswa. Instrumen yang digunakan dalam penelitian ini adalah lembar observai guru, lembar penilaiai siswa dan dokumentasi. Analisis yang digunakan adalah analisis data deskriptif kuantitatif dalam bentuk prosentase. Bersadarkan hasil penelitian disimpulkan bahwa penerapan metode tutor teman sebaya dapat mengoptimlakan ketrampilan pada mata pelajaan Alat Mesin Pertanian siswa kelas X ATPH 1 SMK N 1 Nanggulan. Hasil penelitian Siklus 1 menunjukkan ketrampilanr siswa sebesar 66,7% dan pada siklus 2 meningkat menjadi 91,67%.
EFEKTIFITAS PENERAPAN PENDIDIKAN BERBASIS KOMPETENSI PADA SISTEM PENDIDIKAN DAN PELATIHAN KEJURUAN (VET)
Authors: SISWAHYUDI NOPIAN , HELMI HELMI , PURNAMAWATI PURNAMAWATI
Published: June 2022

This article aims to review the literature on the effectiveness of implementing competency-based education in the vocational education and training (VET) system. The research method used is the literature study method, with data collection techniques in the form of documenting the sources of literature documents. The source of this literature study is in the form of 12 online journal articles. Based on the results of the research review, it can be concluded that: a). Competency-based curriculum is a learning strategy that places students in realistic situations where they have to show whether they can solve certain problems and how they do it. b) The application of competency-based education in the vocational education and training (VET) system is effective in preparing students to improve their skills in facing the world of work, although they still have shortcomings in terms of the preparation of teaching staff and educational facilities.
ABSTRAKArtikel ini bertujuan mereview literatur tentang efektifitas penerapan pendidikan berbasis kompetensi pada sistem pendidikan dan pelatihan kejuruan (VET). Metode penelitian yang digunakan yaitu metode studi literatur, dengan teknik pengumpulan data berupa dokumentasi sumber- sumber dokumen literatur. Sumber dari studi literatur ini berupa artikel jurnal online sebanyak 12 artikel. Berdasarkan hasil review penelitian dapat ditarik kesimpulan bahwa: a). Kurikulum berbasis kompetensi merupakan strategi pembelajaran yang menempatkan siswa dalam situasi yang realistis di mana mereka harus menunjukkan apakah mereka dapat memecahkan masalah tertentu dan bagaimana mereka melakukannya. b) Penerapan pendidikan berbasis kompetensi pada sistem pendidikan dan pelatihan kejuruan (VET) efektif untuk menyiapkan peserta didik untuk meningkatkan keterampilan dalam menghadapi dunia kerja, meskipun masih memiliki kekurangan dari segi penyiapan tenaga pengajar dan fasilitas pendidikan.
Ascertaining potential debris-flow landslides and associated hazards, NW Himalaya, India
Authors: Chauhan Neha , Sundriyal Yaspal , Shukla Anil D. , Kumar Vipin
Published: June 2022

Alaknanda River valley in the NW Himalaya has been subjected to frequent landslides of different types and sizes owing to its geographical position and topography that receive extreme rainfall from Indian Summer Monsoon and Western Disturbance. Such landslides, mainly debris flow, pose a growing risk to the rapidly growing human population and result in huge sediment influx into river valleys that contribute to fluvial regime changes.

In this study, we have simulated runout characteristics of four debris-flow landslides based on inputs from field observation and high-resolution satellite imagery analysis. These landslides are situated along the river valley and accommodate villages/towns near the crown/toe of landslides. Hillslopes constituting these landslides are mostly made up of schist/quartzite/gneissic rock mass, and regional thrust fault passes in the vicinity, contributing to shearing. A Voellmy-Salm fluid-flow continuum model was used to perform debris flow simulations. Frictional, turbulence, and cohesion parameters are probabilistic to eliminate uncertainty, caused mainly by selective input values.

Results indicated that debris flow from these landslide slopes might reach up to 250 m upstream and downstream along the river during extreme rainfall events, contributing to sediment influx, with a flow velocity and height of 5-10 m/sec and 6-13 m, respectively. Further, the human population residing near the crown/toe of these landslides might be subjected to ground instability and subsequent failure due to shear strength loss. Such predictive studies contribute to the effective evaluation of growing hazards associated with hillslopes during extreme rainfall events. 

Keywords: Debris flow; Rainfall; Himalaya
Late Weichselian history of the Moravian Sahara cold-climate dune field, Lower Moravian Basin, Czechia
Authors: Holuša Jakub , Nývlt Daniel , Woronko Barbara , Kuda František , Moska Piotr , Matějka Michael , Stuchlík Radim
Published: June 2022

Aeolian dune field pattern could provide a very detailed image of the influence of environmental controlling factors (wind regime, topography, sediment supply and others) to its development. Moravian Sahara dune field located in Southern Moravia, Czechia, and thus far away from the European Sand Belt (i.e. the area of major aeolian accumulations in Europe), represent a unique archive reflecting the effects of these variables. Even despite its remoteness from the Fennoscandian Ice Sheet during the Last Glacial Maximum, the permafrost occurred in Southern Moravia, and thus periglacial processes operated here. Different approaches including LiDAR DTM analysis, ground-penetration radar (GPR), and near-surface wind modelling were applied to investigate the role of the controlling factors. Two groups of differently oriented periglacial-related dunes (ENE-WSW and N-S) have been distinguished via the DTMs, suggesting a significant twist in atmospheric circulation connected with the retreat of the Fennoscandian Ice Sheet after the Last Glacial Maximum. Beside that, a strong influence of the local topography to the modification of the wind flow and the possible sediment sources were distinguished and described. Furthermore, confrontation of the reconstructed palaeowind directions with the modelled atmospheric circulation during the Weichselian and the OSL ages of aeolian sediments enabled the temporal assignment of the Moravian Sahara dune field development to the Late Pleniglacial and Late Glacial periods. Thus, our results show their applicability to the very detailed study of the influence of environmental conditions on the development of the cold-climate aeolian dune fields.
Cova Rosa revisited. New geoarchaeological research at the Upper Pleistocene – Lower Holocene site of Cova Rosa (Sardéu, Ribadesella, Asturias, Spain).
Authors: Jordá Pardo Jesús F. , Carral Pilar , Duarte Carlos , Maestro Adolfo , Maximiano Alfredo , Molina Juana , Obeso Ramón , L´Esperteyu Cavernícola Espeleo Club Colectivo Espeleológico , Álvarez-Fernández Esteban
Published: June 2022

The karstic cavity of Cova Rosa (Sardéu, Ribadesella, Asturias), developed in the La Escalada limestones (Moscovien, Carboniferous), contains an important archaeosedimentary sequence covering the Late Upper Pleistocene and the Lower Holocene. This sequence, excavated during the second half of the 20th century by Jordá Cerdá and Gómez Fuentes (1982), presents levels of Solutrense, Lower and Upper Magdalenian and Mesolithic. The sequence was studied sedimentologically by Hoyos Gómez (1979). In the last years members of a large research team are working again on this site and its materials (Álvarez-Fernández and Jordá Pardo, 2018) and in this contribution we present the new lithostratigraphic sequence that has been studied again with geoarchaeological methodology. In addition, thanks to the 22 radiocarbon dates obtained (Álvarez-Alonso et al., 2021), we can place the sequence on the Quaternary chronostratigraphic scale.

Referencias

 Álvarez-Fernández, E. y Jordá Pardo, J.F. (Eds.) (2018). El poblamiento prehistórico en el valle del Sella. Cincuenta años del descubrimiento de la cueva de Titot Bustillo y 60 de las primeras intervenciones del profesor Francisco Jordá en las cuevas de El Cierro y Cova Rosa (Ribadesella, Asturias). Asociación Cultural Amigos de Ribadesella, Universidad de Salamanca y UNED, Ribadesella, 208 p.

Álvarez-Fernández, E.; Jordá-Pardo, J. F.; Arias, P.; Bécares, J.; Martín-Jarque, S.; Portero, R.; Teira, L. C.; Douka, K. (2021). Radiocarbon dates for the late Pleistocene and early Holocene occupations of Cova Rosa (Ribadesella, Asturias, Spain), Radiocarbon, 63 (3): 1053-1072. DOI: 10.1017/RDC.2021.18

Hoyos Gómez, M. (1979). El karst de Asturias en el Pleistoceno superior y Holoceno. Estudio morfológico, sedimentológico y paleoclimático. Tesis doctoral, Universidad Complutense de Madrid, 446 p.

Jordá Cerdá, F.; Gómez Fuentes, A. (1982). Cova Rosa-A. Universidad de Salamanca, Salamanca, 108 p.
Asymmetric uplift in the NW Iranian Plateau: An insight from the dynamic divide migration of Ardebil Basin
Authors: Moumeni Mohammad , Delchiaro Michele , Della Seta Marta , Nozaem Reza
Published: June 2022

Drainage divides, the elevated terrain that separates neighboring drainage basins are dynamic features of a landscape that regularly migrate over time due to the development of river networks. Tectonic uplift may considerably influence such a migration by making some basins aggressors with respect to the adjacent ones. In this study, we focus on the effects of tectonic uplift on the Ardebil Basin drainage divide located adjacent to the central Talesh Mountains in the NW sector of Iranian Plateau. Talesh Mountains are prominent tectonic features of the landscape associated with the compressional stresses transferred from the Arabia-Eurasia continental collision. The structural evolution of this range is delineated by several deformation phases in the Late Cenozoic. The regional uplift associated with the right-lateral strike-slip kinematics with a reverse component of the N-NW-trending Talesh Fault, which bounds the Talesh Mountains to the east, has an important role in the tectonic activity of the region. The effects of these tectonic uplift and deformation phases on the landscape and their footprints on the geomorphological architecture of the study area are not fully described to date. Therefore, we used the tools for quantifying drainage divide stability (χ and Gilbert metrics) in order to outline the spatial pattern of uplift in this area. Since, a single divide may be heterogeneous in channel elevation, relief, and gradient values in its different portions, we segmented the Ardebil Basin main divide into 14 sections to calculate the Gilbert metrics and χ. Considering the uniformity of the cross-divide precipitation and rock erodibility, we can infer that divide migration is occurring in the study area in response to the asymmetric uplift and erosion patterns. The results of Gilbert metrics show that the NW and SE sectors of the Ardebil Basin divide are stable, suggesting a quasi-steady state condition. However, based on the χ index, these segments have the potential to move towards the interior of the plateau. Conversely, the NE segments of the main divide are dynamic and currently moving towards the SW, as suggested also by the χ index map. Therefore, we infer that the NE sectors of the Ardebil Basin are in an uplift-driven migration status as a result of an asymmetric uplift controlled by the activity of the Talesh Fault.
Geomatic techniques applied to the rock glacier of Corral del Veleta (Spain) during the period 2001-2019.
Authors: de Sanjosé Blasco José Juan , Atkinson Alan D. , Sánchez Fernández Manuel , Gómez Ortiz Antonio , Salvador Franch Ferran , Salvá Catarineu Montserrat
Published: June 2022

The rock glacier of Corral del Veleta is located in the southwest of the Mediterranean basin, in the Sierra Nevada mountain range (Spain), being the highest in the Iberian Peninsula. It is located in the Quaternary circus of Guarnón at an altitude of 3,100 m, below the peak of Veleta at 3,398 m and facing northeast. The monitoring carried out during the 2001-2019 period has been carried out through different geomatic techniques: Topography, Photogrammetry, GNSS, TLS, UAV & GPR. Thermal measurements of the active layer have been added to these techniques. The analysis and results of the monitoring carried out show that it is in an accelerated process of immobilization and the relict glacial ice and permafrost on which it sits show a continuous degradation. The origin of the changes can be related to the variations in the dominant climate in the high mountains of the Sierra Nevada, particularly since the last third of the 20th century and the beginning of the 21st century.
The role of man on Landcover dynamics of the Jakiri Area of the North West Region of Cameroon
Authors: Nkwemoh Clement , Wirsiy Destain
Published: June 2022

THE ROLE OF MAN ON LAND COVER DYNMICS IN THE JAKIRI AREA,

NORTH WEST REGION OF CAMEROON

By

Clement Anguh Nkwemoh & Destain Wirsiy

The University of Yaounde 1

ABSTRACT

Several Landscape degradation forms have attracted our attention in the Jakiri area on the North Eastern edge of the High Lave Plateau of Cameroon. Landscape degradation has become a major issue in contemporary studies, owing to its impact on society. This study aims to identify mainly various human factors responsible for Land cover dynamics. In order to complete this research, we adopted Classical and Empirical Approaches. These relied on the collection of data from secondary and primary sources. Questionnaires were administered to 310 farmers and 84 pastoralists in 17 villages. Focus Group Discussions and Interviews were equally carried out. The topographic map of Nkambe NB32XVII scale: 1:200 000, was exploited. The MSS, TM and ETM + Enhanced Thematic Mapper Plus as well as ASTER images for 2007 were used. Data was treated with the use of SPSS, ArcGIS and ERDAS IMAGINE software. The study reveals that anthropogenic actions are predominant in degradation meanwhile physical factors are only contributory in the degradation processes that rendered the Jakiri Plateau susceptible to soil erosion and mass movements. The Normalized Different Vegetation Index (NDVI) revealed a decrease in NDVI values from +0.92 in 1988, +0.74 in 2001 and +0.5 in 2020, showing a vegetation decrease. Meanwhile, the Land Cover Classification revealed a change in forest/land cover, from 24.4% in 1988 to 9.83% in 2020 with a decrease in forest cover of 14.5%. On the contrary, built up area, grassland (savannah) and bare surfaces have witnessed an increase in land cover classes from 34.4%, 10%, 31.2% in 1988 to 37.7%, 14%, 38% in 2020. Our study equally identified population pressure, deforestation, rudimentary agricultural activities, overgrazing and the introduction of eucalyptus cultivation as a form of agroforestry that transformed the landscape of Jakiri. The solutions that have been proposed, focus on landscape restoration through improved farming systems such as agroforestry, and also the application of certain technical methods. The solutions are socially just, flexible, adaptable, economically viable and most importantly ecologically sound.

 

Keywords: Anthropic activities; vegetal degradation, GIS, Land cover change; agrarian and

technical measures

 
An investigation into the threshold of sediment motion, in two non-uniform English gravel-bed rivers
Authors: Remers Amelia , Heritage George , Entwistle Neil
Published: June 2022

The sediment dynamics of river systems are of significant importance from an ecological, social and engineering viewpoint and are defined by complex relationships of numerous variables. It is widely accepted amongst authors that as flow increases as does the amount and size of sediment entrained. Threshold theories surrounding this have been proposed by many authors including Hjulstrom, Van Rijn, Du Boys and Shields. The aim of this research is to investigate thresholds of motion for sediments within bi-modal riverbeds, including examining incipient motion for various particle sizes. Previous research methods which have investigated this have focused on either field methods using small sample populations from sediment traps and sediment tracers or laboratory studies (flume models). In this paper an alternative method is presented utilising repeat UAV imagery of two gravel-bed river reaches in England to identify individual sediment clasts and monitor movement. By determining whether a sediment has moved or stayed and comparing this to a maximum flow rate during the interval between surveys, derived from hydraulic modelling, a maximum local shear stress value can be established for when each grain is mobilised. Initial findings have shown that as flow increases so does the amount of sediment moved. However, the size of mobilised sediment does not necessarily increase. Sediments over a certain size (0.3 m B-Axis length) display little movement despite rising shear stress values. Shielding and exposure are also investigated to examine why these larger sediments remain stable despite increasing local shear stress values. This has shown that in non-uniform gravel-bed rivers bed armouring and sediment sorting can heavily impact transportation. Armouring of coarser sediments consolidates a bed leaving finer sediments exposed to the flow and constantly moving through the system. Furthermore, this bi-modal sediment impacts roughness within the channel. A smooth channel with cohesive material decreases roughness, whereas in a non-uniform channel with larger grains roughness increases; this is turn makes movement of grains more difficult. The conclusions established within this research are of significant importance to understanding the complex relationships and various parameters for sediment dynamics within these systems.
Analysis of karst geodiversity in the Garraf massif (Catalonia). 
Authors: Micheo Fus , Piña Jordi , Vicens Marc , Robledo Pedro , Carles Rosa , Pi Eulàlia , Picart Joan , Cirés Jordi
Published: June 2022

The Garraf Massif is a remarkable example of geodiversity in a karstic environment. It is located next to the Catalan coast, to the SW of Barcelona city, and is formed mainly by Cretaceous and Jurassic carbonate rocks in which karst develops. It contains many exokarstic morphologies (microforms and megaforms), as well as an extraordinary endokarst, represented by large caves and deep vertical shafts, which condition the drainage.

Within the framework of the "Geoanthropic Map of Catalonia" project carried out by the Institut Cartogràfic i Geològic de Catalunya (ICGC), a series of cartographies have been made and published at 1:25 000 scale, with a total extension of about 650 km2, which has allowed a detailed mapping of the different karstic morphologies present in the study area (karren, skinholes, palaeopolje, etc.).

The aim of this work is, on the one hand, to analyse the diversity of karst environment by describing the karstic landforms, and on the other hand, to offer an overview of some aspects linked to the karst massif, such as the relationship between the karstic morphology with the structure and lithology of carbonate rocks and with subterranean hydrology, or the physicochemical characterization of residual sediments from decalcification (terra rossa) that are found filling sinkholes and cracks in the rock.

It is an active karst with a very efficient and well-ranked drainage system, which coexists with a developed paleokarst, whose main witness is the Begues polje as well as several paleo-caves unearthed along the coastline.

The Garraf Massif is a protected natural area (Plan de Espacios de Interés Natural), so it benefits from a high degree of protection, and is included in the inventory of Places of Geological Interest in Spain (Geozone 348), being a natural laboratory of extraordinary richness with a great didactic, informative, and scientific value.
First glacial chronology in Corsica (Western Mediterranean Sea) based on 10Be moraine dating: evidence of two glacier extents since the Last Glacial Maximum
Authors: Chenet Marie , Brunstein Daniel , Jomelli Vincent , Team Aster
Published: June 2022

The timing of past glacier fluctuations is poorly constrained in Corsica island (Western Mediterranean Sea). Although several glacial landforms and deposits were described, there are no absolute glacial chronology. We will present 19 new 10Be cosmic-ray exposure ages (CRE) of boulders collected from 4 moraines located in the area of the Bastani Lake (Monte Renoso, Northern Corsica). For the first time on a Mediterranean island, mountain glacier fluctuations are documented from moraine CRE for the Lateglacial Period. Two main glacier advances since the Last Glacial Maximum are identified. 12 boulders of three moraines dated between 14.98 ± 0.89 ka BP and 18.88 ± 1.04 ka BP reveal a glacier extent during the Oldest Dryas (Heinrich Stadial 1 - HS1). 5 boulders of one moraine dated between 12.13 ± 0.69 ka BP and 13.93 ± 0.79 ka BP are attributed to the Late Glacial–Younger Dryas transition. Results and associated past Equilibrium Line Altitude will be compared with those in the Mediterranean mountain ranges. Implications for regional climatic conditions will be discussed.
Large landslides are concentrated along Patagonian Ice Sheet margin
Authors: Břežný Michal , Pánek Tomáš , Harrison Stephan , Schönfeldt Elisabeth , Winocur Diego
Published: June 2022

Deglaciation of mountain ranges promotes landslides of various scales and types, and many of them may present a major hazard. It is commonly thought that the main concentration of landslides is located in parts of the mountain ranges that have pronounced topography, high amount of precipitation and strong tectonic activity. Based on our mapping of large landslides (>1km2) over an extensively large area of Southern Patagonia (~305,000 km²), we show that the distribution of landslides can have the opposite character. The largest landslides within the limits of the former Patagonian Ice Sheet (PIS) are concentrated along its eastern margins and thus occupying lower, tectonically less active, and arid part of the Patagonian Andes. In contrast to the heavily glaciated, highest elevations of the mountain range, the peripheral regions have been glaciated only episodically. However, a combination of glaciation, weak volcanic and sedimentary rocks, sufficient relief, and presence of large glacial lakes in the past, created favourable conditions for formation of huge number of large landslides along eastern margin of PIS. We explain the scarcity of large landslides in the highest parts of the PIS by presence of strong granitic rocks and long-term glacial modification, that adjusted topography for efficient ice discharge. Our model is limited to large bedrock landslides as shallow slides and rock falls are abundant in the highest and western part of the Andes.
Quantifying the direct impacts and risks of large urban gullies in the Democratic Republic of Congo
Authors: Ilombe Mawe Guy , Lutete Landu Eric , Makanzu Imwangana Fils , Nzolang Charles , Michellier Caroline , Poesen Jean , Bielders Charles , Dewitte Olivier , Hubert-Ferrari Aurélia , Vanmaercke Matthias
Published: June 2022

Large urban gullies (UGs) cause major infrastructural damages and often claim casualties in many tropical cities of the Global South. Nonetheless, our insight into this new type of geo-hydrological hazard remains limited to some case studies and the overall impacts remain poorly quantified. Here, we aim to bridge this gap by making a first assessment of the number of persons affected by urban gullies at the scale of the Democratic Republic of Congo (DRC). We used Google Earth imagery in combination with local news sources and earlier research to identify 25 cities in DRC where UG occur at a significant scale (at least ten UGs). This list is likely exhaustive. Next, for each of these cities, we used Google Earth imagery and other high resolution satellite images to map all visible UG, evaluate their expansion rate and inventorize detectable damages to houses and roads. In total, >2,000 UGs were mapped across the 25 affected cities.  Overall, the problem of UGs in DRC is especially acute in the cities of Kinshasa, Mbujimayi, Kikwit, Tshikapa and Kananga. Over 90% of these gullies were active during the observation period (typically from 2002 to 2020). 
Next, we assessed the total number of persons that are directly affected, as well as the number of persons currently at risk. Using available high resolution population density data and taking into account the current position of urban gullies, we estimate that around 68,700 people were directly displaced due the formation and expansion of UGs over the last 15 years. This corresponds to an average of ca. 4,300 persons per year. By considering the population that lives in the direct vicinity (<100 m) of an UG, we estimate that around 1.3 million people in D.R. Congo are currently at risk and/or experience significant impacts because of UGs (e.g. reduced land value, problems with trafficability, stress). This number has doubled over the past 10 years (2010-2020) and will likely continue to increase as a result of urban expansion and climate change.  
Overall, this research shows that urban gullying is a very serious problem in the Democratic Republic of Congo, but likely also in many other countries of the Global South. More research is needed to better understand this processes and, ultimately, to prevent and mitigate its impacts. The results and the database of this study provide an important step towards this.
Geological and morpho-tectonic analysis for defining active fault segmentation: case studies from the central Apennines, Italy
Authors: Dixit Dominus Girolamo , Maceroni Deborah , Falcucci Emanuela , Galadini Fabrizio , Gori Stefano , Molin Paola , Moro Marco , Saroli Michele
Published: June 2022

Up to now, the complexity and the uncertainty in defining the extent down-dip and along-strike of active faults led to the elaboration of several methods to establish structure 3D geometry. Therefore, different approaches produce different scenarios of seismogenic rupture for the same active tectonic structure. Here we investigate two active fault systems of the central Apennines of Italy: the Roveto Valley Fault and the Laga Mts. Fault. We specifically aim to the understanding of along-strike segmentation of these tectonic structures to contribute to improve the knowledge of the seismotectonic setting of the central Apennines. Overall, our goal is to make a step forward toward the comprehension of the wide theme of seismogenic fault segmentation.

The main uncertainties regarding the two fault systems are different. In the case of the Roveto Valley Fault, the uncertainty is twofold: 1) the current activity of the fault is debated; according to some authors, fault activity ended during the Middle Pleistocene, whereas others suggest the fault is still active and seismogenic; 2) the extent of the proposed active section of this tectonic structure is not clearly defined, and this is relevant in a seismotectonic perspective. The Laga Mts. fault system is a complex tectonic structure whose activity is well geologically documented for the southern section of the system; moreover, the fault system played a key role in the seismogenic process of the 2016-2017 central Italy earthquake sequence. Some authors interpret the fault as the surface expression of a single large seismogenic source, capable of generating seismic events of Mw ≈ 6.7. Other authors, instead, propose that this system consists in two structurally aligned but kinematically independent faults, the Amatrice and Campotosto faults. Following the 2016-2017 seismic sequence, an important debate is taking place within the scientific community about the definition of 1) the individual seismogenic sources that make up the Laga Mts. fault system and 2) the geometric and kinematic relationship between the fault(s) at surface and its (their) possible prolongation at depth as crustal major seismogenic sources.

Through morphological, morphotectonic and structural analyses we propose segmentation criteria and possible segmentation scenarios for these two structures. These allow us to estimate the maximum coseismic rupture and the maximum magnitude expected from a single seismic event for the investigated fault, improving the seismotectonic knowledge of the central Apennines.
Proglacial geomorphic disturbances drive the spatial distribution of the rare alpine species Trifolium Saxatile All.
Authors: de Bouchard d'Aubeterre Géraud , Till-Bottraud Irène , Roussel Erwan , Fort Noémie , Bizard Léa , Tissot Nicolas , González Eduardo , Liébault Frédéric , Petit Stéphane , Pringault Jérémy , Corenblit Dov
Published: June 2022

Glacier retreat has increased in the European Alps during the last four decades. This affects proglacial geomorphic processes and the spatial distribution of plants. We assessed how the type and the magnitude of geomorphic disturbance control the spatial distribution of a rare alpine plant species: Trifolium saxatile All., whose main habitats are proglacial forelands and alluvial bars and banks, within the Glacier Blanc et Glacier Noir catchment area (Ecrins National Park, French Alps). Based on field observations during the summers of 2020 and 2021, we produced a map combining geomorphological deposits and presence-absence of T. saxatile to detect which geomorphological units are relevant for our study. We determined the magnitude and frequency of superficial sediment reworking between the 2020 and 2021 summers using Radio Frequency IDentification experimentation on moraines slopes and glacio-fluvial deposits on which populations of T. saxatile were observed. Abundance and functional traits (stem height, length and number of inflorescences) were also measured. To analyze the potential impacts of geomorphic disturbances on T. saxatile presence, abundance and intra-specific trait variability, generalized linear mixed models (GLMM) and factor analyses of mixed data (FAMD) were used. Results showed heterogeneity in the geographical distribution of T. saxatile within the proglacial landscape. Clovers preferentially established over three geomorphological units: (i) nearly stabilized lateral moraines, (ii) active braided floodplains and (iii) the exposed young alluvial bars. It was totally absent in purely gravitational landforms (e.g. scree, talus cones). The largest individuals of T. saxatile with many inflorescences were mostly found within the active torrential channel where geomorphic disturbances are intense and frequent but this was however balanced by a low abundance of individuals. On lateral moraines and alluvial terraces, which are almost stabilized and exhibit a lower level of geomorphic disturbances than the active braided floodplain (in terms of magnitude and frequency of movement of RFID tracked sediment particles), individuals were much more abundant, but they were smaller and with less inflorescences compared to the active torrential channel. This study shows the importance of geomorphic processes as key drivers of the spatial distribution, and potentially traits expression, of alpine species living in glaciated catchment areas.
Long-term development of the sediment dynamics of proglacial streams in three alpine catchments
Authors: Betz-Nutz Sarah , Heckmann Tobias , Altmann Moritz , Rom Jakob , Fleischer Fabian , Himmelstoß Toni , Haas Florian , Becht Michael
Published: June 2022

Due to glacier melting since the end of the Little Ice Age, the system of proglacial streams has experienced significant changes. This motivates the question about long-term developments of sediment dynamics in these stream channels with ongoing glacier melting. Previous studies showed cycles of aggradation and degradation in proglacial streams. On the long term, some discovered an aggrading system and others a balanced ratio. However, no long-term data of channel sediment dynamics for several decades and multiple catchments that would enable a comparison have been discussed to date.

Within the project “Sensitivity of High Alpine Geosystems to climate change since c. 1850” (SEHAG), historical digital elevation models (DEMs) were generated from aerial images dating back until 1953. Moreover, from the 2000s on, airborne LiDAR datasets and DEMs based on drone images are available. Numerous DEMs of difference were generated for the three alpine catchments studied by the SEHAG project: Kaunertal and Horlachtal (Tyrol, Austria), and Martelltal (South Tyrol, Italy). These catchments differ regarding their location respective to the alpine main divide and also regarding their percentage of glaciation. This database enables the comparative investigation of sediment dynamics within the main channel system over decades.

Our preliminary results show mainly accumulation next to the glacier tongue, but subsequently a reworking of this accumulated material by channel incision until the channel system reaches a state of stability some years or decades after deglaciation.
Denuded caves on the Nullarbor Plain, Australia
Authors: Ferk Mateja , Lipar Matej
Published: June 2022

Denuded caves are surface expressions of cave passages due to lowering of the surface by denudation and/or breakdown propagation of caves towards the surface. They appear as fragments of channels on the surface, often filled with clastic cave sediments and occasional speleothems. Elongated shallow depressions were recently observed on the surface of the southeastern part of the Nullarbor Plain, and close association with associated collapse dolines suggests that they are denuded caves.

The Nullarbor Plain in southern Australia is among the largest karst outcrops in the world and covers a surface area of approximately 200.000 km2. The bedrock comprises the middle to late Eocene Wilson Bluff Limestone, the Oligocene to early Miocene Abrakurrie Limestone, and the middle Miocene Nullarbor Limestone. The plain has been since the deposition of the Nullabror Limestone uplifted and exposed to subaerial denudation. It is renowned for outstanding flatness with collapse dolines and vertical cave openings (blowholes) being the most common surface karst features. Most of the discovered caves are “shallow caves” in Nullarbor Limestone, generally less than 30 m deep with low collapse chambers. On the other hand, “deep caves” generally extend 50-120 m below the surface in the Wilson Bluff Limestone and may reach exceptional dimensions. Deep and shallow caves are thought to be genetically unrelated, but the speleogenesis of deep caves is still not understood completely, and the recognition of denuded caves might help understand their timing of initial formation.

One hypothesis suggests the phreatic origin of deep caves after the deposition of the Wilson Bluff Limestone and its exposure on the surface during the warm wet climate around 35 to 25 million years ago. Later, around 25 to 10 million years ago, the tectonic basin underwent subsidence and sea transgression in the west-central part, which is on the present surface obscured by even lateral deposition of younger limestones. Therefore, the relatively greater number of denuded caves in the east expressed as simple uniform lines of shallow elongated depressions, the combination of a line of collapses and shallow depressions in the central part of the plain, and greater discovered number of deep caves towards the west could confirm this hypothesis. Namely, the subsidence of the Wilson Bluff in its western part (with caves already formed) could have caused thinner deposition of younger limestones towards the east and the position of cave passages relatively higher. Progressive cave collapses therefore reached the surface on the eastern side sooner (expressed as denuded caves), whilst in the west the breakdown propagation of deep caves has not yet reached the surface.
Long-term effects of wildfire on rock weathering and soil stoniness in the Mediterranean landscapes 
Authors: Shtober-Zisu Nurit , Wittenberg Lea
Published: June 2022

Rock fragments in soil and on the soil surface affect key soil hydrological processes, including water repellency, thermal properties physical degradation, erosion, and productivity. The severe wildfire at Mt. Carmel, Israel, in 2010, caused massive destruction of carbonate rocks. The thermal shock caused extreme exfoliation, producing large and flat clasts, affecting rocks to a depth of up to 20 cm. A decade after the fire, most flakes and spalls disappeared from the rock outcrops and adjacent soils. From these observations, this study pursued two objectives: (a) to monitor and analyze the spatio-temporal distribution of the disintegrated flakes 10 years after the fire and (b) to test the hypothesis that fires contribute to increased soil stoniness via physical and chemical flake erosion. This research showed that after a decade, most of the spalled surface on the burned outcrops was lost, broken down and pulverized, exposing new rock surfaces to atmospheric and weathering processes. The most prominent effects were changes in surface stoniness on the rendzina soils over the chalks, while there was less impact on the dolomite and limestone samples. The stoniness of the non-burned chalk was 23-39% and increased significantly to 69-86% in the burned area. Chalk erosion produced large (>16 mm, median 8-16 mm) and abundant gravel, suggesting fragmentation of large spalls, and particles that lost their bladed shapes becoming oblate and equant. While earlier works suggested that increasing rock fragment cover is often associated with the removal of fine particles, our results showed a substantial increase in rock fragments due to fire-induced exfoliation of rock surfaces, leading to long-term changes in soil properties. We therefore propose that the size, shape, and spatial distribution of rock fragments should be considered when examining the effects of rock fragments on hydrological and geomorphological processes or on post-fire soil rehabilitation.
Rock slope and rockfall dynamics in flysch formation under mid-latitude cold climate
Authors: Gauthier Francis , Birien Tom , Meloche Francis
Published: June 2022

Stratified sedimentary rock slope are conducive to differential erosion. The retreat and settlement of weak rock strata (shale, siltstone) causes the gradual cantilevering of stronger rock strata (sandstone, greywacke), contributing to the development of tension cracks. As a result, blocks may break away from these stronger rock strata and they will eventually slide or topple on the eroding weak rock strata below. Since 1987, more than 17 500 rockfalls reaching the road have been reported by the Québec Ministry of Transport (MTQ) in northern Gaspésie (eastern Canada). Although these events are well correlated with the meteorological conditions, it is not clear if and how the weathering process affect the failure mechanism. These dynamics have been observed, but rarely studied to 1) determine the mechanical stresses and weathering conditions that promote rock cracking and 2) assess the effect of meteorological conditions on the mechanical deformations promoting rockfalls. We use the cantilever beam theory to model critical cantilever length (block size) and a frost cracking model (Rempel et al., 2016) was then used to explain the decrease of rock tensile strength over time. Meteorological instruments and crack-meters were installed on a flysch rockwall to monitored and explained mechanical deformations. In addition, rockwalls were scanned with a terrestrial laser scanner (TLS) during specific pre-targeted meteorological conditions. The results show that the areas of frost damage concentration correspond to those of maximum stress in the overhanging blocks. The gradual settling measured with the crack-meters in the shale strata causes the destabilization of the above stronger rock strata. Sandstone blocks may then slide or topple on the inclining plane. Heavy rainfall, snowmelt and freeze-thaw cycles are then responsible for most irreversible deformation in both silstone/shale strata and sandstone strata. Over a period of 18 months, 17 LiDAR surveys have allowed to identify 1287 rockfalls with a magnitude above 0.005 m³ on a scanned surface of 12 056 m² resulting in retreat rate between 2.8 to 5.4 mm/years. In winter, rockfall frequency is 12 times higher during a superficial thaw than during a cold period in which temperature remains below 0°C. In summer, rockfall frequency is 22 times higher during a heavy rainfall event than during a dry period. Superficial freeze-thaw cycle (< 50 cm) causes mostly a high frequency of small magnitude events while deeper spring thaw (> 100 cm) results in a high frequency of large magnitude events. Influence of meteorological conditions on mechanical deformations and on rockfall frequency and magnitude is crucial in order to improve risk management since large magnitude events represent higher potential hazards.
Sea-level rise and land subsidence of low-lying coasts: the study case of Tavoliere delle Puglie (Southern Italy)
Authors: Petio Paolo , Scardino Giovanni , Serpelloni Enrico , Refice Alberto , De Santis Vincenzo , Rizzo Angela , Zingaro Marina , Capolongo Domenico , Anzidei Marco , Scicchitano Giovanni
Published: June 2022

The ongoing climate changes are determining an increase of sea-level rise with potential effects on the low-lying coasts. Future projections show the sea-level rise scenarios with an increase of about 1 m than present sea level at 2100. These scenarios are of great interest considering that low-lying coastal areas could be fully submerged with annexed damages at the socio-economic activities. This applies for the low-lying coasts particularly affected by subsidence processes, which could be attributed to the anthropogenic impact, in particular those areas influenced by well exploitations, infrastructure and resort buildings, dams and long-coast interventions. In this work, the coastal plain of Tavoliere delle Puglie (Apulia, Southern Italy) was surveyed to assess the impact of sea-level rise at 2100. The main factors considered for the assessment of sea-level rise impact are the following: future sea-level projections, high-resolution topographic data, vertical land movements (VLMs), and erosion rates. The sea-level projections were assessed through the recent climate models of Intergovernmental Panel of Climate Change 2021 for the Gulf of Manfredonia. Topographic data were obtained through Terrestrial Laser Scanner (TLS) surveys for the coastal zone of the Tavoliere delle Puglie and Light Detection and Ranging (LiDAR) for the landward areas. The VLMs were obtained through an integrated analysis between Global Navigation Satellite System (GNSS) stations and Interferometric Synthetic-Aperture Radar (InSAR) data. Erosion rates were assessed analysing the historical maps and aerial photographs and integrating them with TLS and LiDAR data. The topography at 2100 was reconstructed considering the VLM and erosion rate values in order to assess the coastal surface prone to submersion. The submersion surfaces were assessed through a mathematical model that considers the sea-level projections, erosion rates and VLM existing in specific areas. The results highlighted significant submersion in the coastal areas characterized by high land subsidence and erosion rates, with surface loss extending over 1 km landward. In this work, the modelled impact of sea-level rise highlighted the high vulnerability of touristic resorts and socio-economic activities along the coastal plain of Tavoliere delle Puglie.