Snow-avalanche boulder fans in Jotunheimen, southern Norway: Schmidt-hammer exposure-age dating, geomorphometrics, dynamics and evolution

Eleven snow-avalanche boulder fans were dated from two high-alpine sites in Jotunheimen using Schmidt-hammer exposure-age dating (SHD) and lichenometry. Average exposure ages of the surface boulders ranged from 2285 ± 725 to 7445 ± 1020 years and demonstrate the potential of SHD for dating active landforms and diachronous surfaces. Application of GIS-based morphometric analyses showed that the volume of rock material within 10 of the fans is accounted for by 16-68 % of the combined volume of their respective bedrock chutes and transport zones. It is inferred that the fans were deposited entirely within the Holocene, mainly within the early- to mid Holocene, by frequent avalanches carrying very small debris loads. Relatively small transport-zone volumes are consistent with avalanches of low erosivity. Excess chute volumes appear to represent subaerial erosion in the Younger Dryas and possibly earlier. Debris supply to the fans was likely enhanced by early-Holocene paraglacial processes following deglaciation, and by later permafrost degradation associated with the mid-Holocene Thermal Maximum. The latter, together with the youngest SHD age from one of the fans, may presage a similar increase in geomorphic activity in response to current warming trends

Deglaciation of the highest mountains in Scandinavia at the Younger Dryas-Holocene transition: evidence from surface exposure-age dating of ice-marginal moraines

Surface exposure-age dating was applied to rock surfaces associated with ice-marginal moraines at elevations of ~1520–1780 m a.s.l. on the slopes of Galdhøpiggen and Glittertinden, the two highest mountains in Scandinavia located in the Jotunheimen mountains of central southern Norway. This is important for understanding the pattern and timing of wastage of the Scandinavian Ice Sheet at the Younger Dryas-Holocene transition. Cosmogenic exposure dating (here 10Be dating) of boulders from the moraine ridges yielded overall mean ages (corrected for glacio-isostatic uplift, surface erosion and snow shielding) of ~11.6 ka from Galdhøpiggen and ~11.2 ka from Glittertinden. Similar 10Be ages were also obtained from additionally collected proximal and distal erratic boulders and bedrock samples.These enabled age calibration of Schmidt-hammer R-values and independent Schmidt-hammer exposure-age dating (SHD) of the moraine ridges, which yielded comparable mean SHD ages of ~10.8 ka and ~10.6 ka from the Galdhøpiggen and Glittertinden sites, respectively. Taking account of the age-resolution and other limitations of both dating techniques, the results suggest that the two sets of moraines have approximately the same age but that neither technique can distinguish unambiguously between moraine formation in the late Younger Dryas or Early Holocene. Together with features of moraine-ridge morphology and estimates of equilibrium-line altitude depression (ΔELA) of ~360–575 m (corrected for land uplift), the results imply moraine formation during short-lived re-advances of active glaciers, at least the lower reaches of which were warm-based. It is concluded that the local glaciers remained active and advanced during deglaciation either very late in the Younger Dryas or very early in the Holocene, possibly in response to the Preboreal Oscillation at ~11.4 ka. The study supports the concept of a thin Younger Dryas Ice Sheet and places time constraints on the timing of final deglaciation in southern Norway

Catchment-scale patterns of geomorphic activity and vegetation distribution in an alpine glacier foreland (Kaunertal Valley, Austria)

The interaction between geomorphological and ecological processes plays a significant role in determining landscape patterns in glacier forelands. However, the spatial organization of this biogeomorphic mosaic remains unclear due to limited catchment-scale data. To address this gap, we used a multi-proxy analysis to map potential geomorphic activity related to surface changes induced by sediment transport on drift-mantled slopes and a glaciofluvial plain. High-resolution vegetation data were used to generate a catchment-scale map delineating vegetation cover and stability thresholds. The two maps were integrated, and an exploratory regression analysis was conducted to investigate the influence of geomorphic activity on vegetation colonization. The multi-proxy analysis resulted in an accurate mapping of catchment-wide geomorphic activity, with a validation accuracy ranging from 75.3% through field mapping to 85.9% through plot sampling. Through vegetation cover mapping, we identified biogeomorphic stability thresholds, revealing a mosaic of vegetation distribution. Distinct colonization patterns emerged across different geomorphic process groups, influenced by process magnitude and the time since the last disturbance event. The exploratory regression analysis showed that vegetation distribution is significantly affected by geomorphic processes. Based on the overlay of results regarding geomorphic activity and vegetation distribution, we suggest an age-independent framework that indicates four potential situations of biogeomorphic succession

Disease severity in hospitalized COVID-19 patients: comparing routine surveillance with cohort data from the LEOSS study in 2020 in Germany

Introduction Studies investigating risk factors for severe COVID-19 often lack information on the representativeness of the study population. Here, we investigate factors associated with severe COVID-19 and compare the representativeness of the dataset to the general population. Methods We used data from the Lean European Open Survey on SARS-CoV-2 infected patients (LEOSS) of hospitalized COVID-19 patients diagnosed in 2020 in Germany to identify associated factors for severe COVID-19, defined as progressing to a critical disease stage or death. To assess the representativeness, we compared the LEOSS cohort to cases of hospitalized patients in the German statutory notification data of the same time period. Descriptive methods and Poisson regression models were used. Results Overall, 6672 hospitalized patients from LEOSS and 132,943 hospitalized cases from the German statutory notification data were included. In LEOSS, patients above 76 years were less likely represented (34.3% vs. 44.1%). Moreover, mortality was lower (14.3% vs. 21.5%) especially among age groups above 66 years. Factors associated with a severe COVID-19 disease course in LEOSS included increasing age, male sex (adjusted risk ratio (aRR) 1.69, 95% confidence interval (CI) 1.53–1.86), prior stem cell transplantation (aRR 2.27, 95% CI 1.53–3.38), and an elevated C-reactive protein at day of diagnosis (aRR 2.30, 95% CI 2.03–2.62). Conclusion We identified a broad range of factors associated with severe COVID-19 progression. However, the results may be less applicable for persons above 66 years since they experienced lower mortality in the LEOSS dataset compared to the statutory notification data.Peer Reviewe

Global application of an unoccupied aerial vehicle photogrammetry protocol for predicting aboveground biomass in non‐forest ecosystems

P. 1-15Non-forest ecosystems, dominated by shrubs, grasses and herbaceous plants, provide ecosystem services including carbon sequestration and forage for grazing, and are highly sensitive to climatic changes. Yet these ecosystems are poorly represented in remotely sensed biomass products and are undersampled by in situ monitoring. Current global change threats emphasize the need for new tools to capture biomass change in non-forest ecosystems at appropriate scales. Here we developed and deployed a new protocol for photogrammetric height using unoccupied aerial vehicle (UAV) images to test its capability for delivering standardized measurements of biomass across a globally distributed field experiment. We assessed whether canopy height inferred from UAV photogrammetry allows the prediction of aboveground biomass (AGB) across low-stature plant species by conducting 38 photogrammetric surveys over 741 harvested plots to sample 50 species. We found mean canopy height was strongly predictive of AGB across species, with a median adjusted R2 of 0.87 (ranging from 0.46 to 0.99) and median prediction error from leave-one-out cross-validation of 3.9%. Biomass per-unit-of-height was similar within but different among, plant functional types. We found that photogrammetric reconstructions of canopy height were sensitive to wind speed but not sun elevation during surveys. We demonstrated that our photogrammetric approach produced generalizable measurements across growth forms and environmental settings and yielded accuracies as good as those obtained from in situ approaches. We demonstrate that using a standardized approach for UAV photogrammetry can deliver accurate AGB estimates across a wide range of dynamic and heterogeneous ecosystems. Many academic and land management institutions have the technical capacity to deploy these approaches over extents of 1–10 ha−1. Photogrammetric approaches could provide much-needed information required to calibrate and validate the vegetation models and satellite-derived biomass products that are essential to understand vulnerable and understudied non-forested ecosystems around the globe.S

Global patient outcomes after elective surgery: prospective cohort study in 27 low-, middle- and high-income countries.

BACKGROUND: As global initiatives increase patient access to surgical treatments, there remains a need to understand the adverse effects of surgery and define appropriate levels of perioperative care. METHODS: We designed a prospective international 7-day cohort study of outcomes following elective adult inpatient surgery in 27 countries. The primary outcome was in-hospital complications. Secondary outcomes were death following a complication (failure to rescue) and death in hospital. Process measures were admission to critical care immediately after surgery or to treat a complication and duration of hospital stay. A single definition of critical care was used for all countries. RESULTS: A total of 474 hospitals in 19 high-, 7 middle- and 1 low-income country were included in the primary analysis. Data included 44 814 patients with a median hospital stay of 4 (range 2-7) days. A total of 7508 patients (16.8%) developed one or more postoperative complication and 207 died (0.5%). The overall mortality among patients who developed complications was 2.8%. Mortality following complications ranged from 2.4% for pulmonary embolism to 43.9% for cardiac arrest. A total of 4360 (9.7%) patients were admitted to a critical care unit as routine immediately after surgery, of whom 2198 (50.4%) developed a complication, with 105 (2.4%) deaths. A total of 1233 patients (16.4%) were admitted to a critical care unit to treat complications, with 119 (9.7%) deaths. Despite lower baseline risk, outcomes were similar in low- and middle-income compared with high-income countries. CONCLUSIONS: Poor patient outcomes are common after inpatient surgery. Global initiatives to increase access to surgical treatments should also address the need for safe perioperative care. STUDY REGISTRATION: ISRCTN5181700

Modeling human induced soil erosion hot spots in a medium-sized agricultural catchment in the Thayatal region, Lower Austria

Bodenerosion durch Wasser beeinflusst fruchtbares Land weltweit da landwirtschaftliche Nutzung die lokalen Auswirkungen von Erosion, wie beispielsweise Bodendegradation, verstärkt. Hinzu kommt, dass transportiertes Sediment das Gerinne erreichen und damit Einfluss auf fluviale Ökosysteme nehmen kann. Der Nationalpark Thayatal in Niederösterreich wird stark vom angrenzenden Einzugsgebiet der Fugnitz beeinflusst. Die landwirtschaftliche Nutzung im Bereich des Zubringers und der dadurch erhöhte Eintrag von Feinsedimenten in das Gerinnesystem hat negative Auswirkungen auf die ökologische Situation der Thaya. Die vorliegende Arbeit ist Teil des Projektes “FugnitzSED” und verfolgt das Ziel, ein vertieftes Verständnis für Erosionsprozesse in einem mittel-großen, landwirtschaftlich genutzten Flusseinzugsgebiet zu erlangen sowie potentielle Gebiete mit erhöhten Erosionsraten auszuweisen. Dabei wird ein prozessbasiertes Erosionsmodell (WEPP/GEOWEPP) verwendet und dessen Eignung für angewandtes Umweltmanagement getestet. Modellierungen wurden dabei auf Einzugsgebietsebene (Sedimentaustrag) sowie für ausgewählte Fokusbereiche (Bodenabtrag) erstellt. Für die Fokusbereiche wurden darüber hinaus modellierte Fließwege getestet. Anschließende Feldbegehungen hatten zum Ziel, die tatsächliche Situation vor Ort aufzunehmen. Der abschließende methodische Schritt bestand darin, die Auswirkungen verschiedener Fruchtfolgen auf den Sedimentaustrag auf Einzugsgebietsebene zu simulieren. Erhöhte Austragsraten wurden vom Modell im Bereich des gesamten Einzugsgebietes ausgewiesen. Felderhebungen und Modellergebnisse deckten sich dabei weitgehend. Hier muss jedoch angemerkt werden, dass in Ermangelung an Daten kein Vergleich mit tatsächlich gemessenen Austragsraten möglich war. Die Schwächen des Models wurden besonders durch den Vergleich zwischen modellierten Fließwegen und kartierten Erosionsrillen bei den beiden kleineren Fokusbereichen (B und C) aufgezeigt. Der Einfluss von mikro-topographischen Strukturen (Pfluglinien und Feldränder) auf die Bildung von Erosionsrillen wurde dabei vom Model nicht erfasst. Simulationen der Verwendung unterschiedlicher Fruchtfolgen zeigte den deutlichen Einfluss landwirtschaftlicher Bearbeitungsweisen auf Bodenabtragsraten. Die vorliegende Arbeit trägt aufgrund dessen zu einem tieferen Verständnis über Erosionsprozesse im Einzugsgebiet der Fugnitz bei. Basierend auf Modellergebnissen (WEPP/GEOWEPP) und in Anlehnung an Fachliteratur wurden abschließend Handlungsoptionen zur Minderung des Sedimenteintrags aufgezeigt.Water-mediated soil erosion affects arable land all over the world. Agricultural production facilitates on-site effects of soil erosion, such as soil degradation, as well as off-site effects as, for instance, sediment-mediated fertilizer and pollutant transport into freshwater ecosystems. The conservation area of the Thayatal National Park in Lower Austria is negatively impacted by these aspects of sediment connectivity due to hillslope to channel sediment transfers within the Fugnitz watershed, the main tributary system of the Thaya River. The objective of this Master’s thesis is to enhance the understanding of soil erosion processes in this medium-sized agricultural watershed. Embedded in the FugnitzSED project, the present thesis aims at investigating potential source areas for high amounts of sediment yield and at testing a process-based erosion model (WEPP/GEOWEPP) for challenges in the context of environmental management. Methods applied include erosion modeling on catchment- and on subcatchment-scale. On catchment level, areas with potentially high amounts of sediment yield are simulated while modeling of small scale (2 – 8 ha) target areas is conducted to simulate on-site processes and to test flow path delineation. Subsequent field investigations seek to provide information on the validation of catchment wide modeling, the comparison of observed erosion rills with modeled flow paths and local erosion processes. In order to provide management options, different land use scenarios are simulated and mitigation strategies are discussed. Hotspot modeling of high amounts of sediment yield show increased rates across the whole catchment area. Comparison of model results and information obtained via field surveys indicate broad agreement. Nevertheless, model validation lacks comparison with actual sediment yield rates, therefore, future research ought to quantify soil erosion in the Fugnitz catchment. The analysis of flow-path-delineation on smaller scale target areas (B and C) indicates that micro-topographic features (e.g. plough lines, field boundaries) are not captured by the model, revealing its weaknesses (location/direction of flow paths, location of deposition areas). Simulation of different management scenarios indicates a considerable influence of crop rotation on predicted erosion rates and highlights the importance of reasoned management strategies. Based on literature research and WEPP/GEOWEPP results, different mitigation strategies for the Fugnitz catchment are developed. As a result possible actions and localization of potential target zones constitute a starting point for future management discussions. The present thesis leads to an improved comprehension of soil erosion processes within the Fugnitz catchment and facilitates the development of different mitigation strategies based on the obtained results

Classifying Sparse Vegetation in a Proglacial Valley Using UAV Imagery and Random Forest Algorithm

Extreme hydro-meteorological events become an increasing risk in high mountain environments, resulting in erosion events that endanger human infrastructure and life. Vegetation is known to be an important stabilizing factor; however, little is known about the spatial patterns of species composition in glacial forelands. This investigation aims to differentiate sparse vegetation in a steep alpine environment in the Austrian part of the Central Eastern Alps using low-cost multispectral cameras on an unmanned aerial vehicle (UAV). Highly resolved imagery from a consumer-grade UAV proved an appropriate basis for the SfM-based modeling of the research area as well as for vegetation mapping. Consideration must be paid to changing light conditions during data acquisition, especially with multispectral sensors. Different approaches were tested, and the best results were obtained using the Random Forest (RF) algorithm with the target class discrimination based on the RGB orthomosaic and the DEM as supplementary dataset. Our work contributes to the field of biogeomorphic research in proglacial areas as well as to the field of small-scale remote sensing and vegetation measuring. Our findings show that the occurrence of vegetation patches differs in terms of density and diversity within this relatively recent deglaciated environment

Classifying Sparse Vegetation in a Proglacial Valley Using UAV Imagery and Random Forest Algorithm

Extreme hydro-meteorological events become an increasing risk in high mountain environments, resulting in erosion events that endanger human infrastructure and life. Vegetation is known to be an important stabilizing factor; however, little is known about the spatial patterns of species composition in glacial forelands. This investigation aims to differentiate sparse vegetation in a steep alpine environment in the Austrian part of the Central Eastern Alps using low-cost multispectral cameras on an unmanned aerial vehicle (UAV). Highly resolved imagery from a consumer-grade UAV proved an appropriate basis for the SfM-based modeling of the research area as well as for vegetation mapping. Consideration must be paid to changing light conditions during data acquisition, especially with multispectral sensors. Different approaches were tested, and the best results were obtained using the Random Forest (RF) algorithm with the target class discrimination based on the RGB orthomosaic and the DEM as supplementary dataset. Our work contributes to the field of biogeomorphic research in proglacial areas as well as to the field of small-scale remote sensing and vegetation measuring. Our findings show that the occurrence of vegetation patches differs in terms of density and diversity within this relatively recent deglaciated environment

Schmidt-hammer exposure-age dating (SHD) of sorted stripes on Juvflye, Jotunheimen (central South Norway): Morphodynamic and palaeoclimatic implications

Measurements with an electronic Schmidt-hammer (RockSchmidt) were conducted on 23 sites of sorted stripes (periglacial patterned ground) on Juvflye, Jotunheimen (central South Norway). All were located above the current lower limit of alpine permafrost. Performing Schmidt-hammer exposure-age dating (SHD) based on application of a new local age-calibration equation for RRock-values yielded SHD-ages between 7975 ± 370 and 6660 ± 355 years ago, which are closely comparable to results obtained previously from sorted circles at the same location. The age estimates are interpreted as ‘composite’ ages indicative of upfreezing of boulders, lateral sorting, and subsequent stabilisation. Formation of patterned ground essentially ceased with the onset of the regional Holocene Thermal Maximum (HTM). Neither sorted stripe sites at higher altitude, continuously underlain by permafrost during the entire Holocene, nor those at lower altitudes affected by re-aggradation of permafrost in the late Holocene show signs of significant recent morphodynamic activity. Likely explanations for early- to mid-Holocene stabilisation include (1) substantial changes of soil moisture conditions and related thermodynamics within the active layer affecting frost action, (2) loss of fine-grained substrate matrix from the coarse stripes and hence reduced frost susceptibility, and (3) exhaustion of supply of boulders from the fines-dominated areas. Whereas the sorted stripe data set as a whole did not reproduce the altitudinal gradient characteristic of sorted circles on Juvflye, the strength of the relationship between sorted stripe mean RRock-values and altitude increased with declining slope gradient. Although interpretation of SHD-ages for patterned ground remains challenging, this successful application of the electronic Schmidt-hammer, with its increased efficiency and technical improvements over the mechanical Schmidt-hammer, offers considerable potential for future SHD-studies in both morphodynamic and palaeoclimatic contexts