bluuebunny/crossref_metadata_2025 huggingface dataset:
Spatiotemporal assessment of ephemeral gully characteristics using low altitude aerial imagery: an approach for quantifying
Authors: Momm Henrique , Wells Robert , Castillo Carlos , Bingner Ronald
Published: March 2020

In agricultural fields, ephemeral gullies are defined as erosional channels formed primarily by overland flow from rainfall events. These channels are characterized by small dimensions, approximately 0.5 to 25 cm in depth, which allows their removal during regular farming operations. This dynamic characteristic coupled with their small size often can conceal soil losses by ephemeral gullies and poses challenges to efforts devised for soil loss quantification and mitigation. In this study, novel surveying and data processing techniques were employed to capture the small scale in topographic variation between two surveys and to assure that changes were due to erosional processes rather than survey miss-alignment. An agricultural field located in Iowa, U.S.A. with an area of approximately 54,500 m2 was surveyed twice: right after the field was planted with corn and approximately one month later, following several rainfall events. A static benchmark point was established at the edge of the field and tied to public geodesic locations. A set of removable ground control points were spread throughout the field and surveyed in relation to the benchmark point. Low altitude aerial images were collected using a quadcopter UAS. Ground control points were used to aid in geospatial registration and to assess final survey accuracy. Standard off-the-shelf commercial software packages were unable compensate for less distortion and a new procedure using Micmac open-source photogrammetry software package was used to account for complex distortion patterns in the raw image data set. The undistorted images were then processed using Agisoft Photoscan for camera alignment, model georeferencing, and dense point cloud generation. Each point cloud representing a time period contained over 1 billion of points (file size > 100GB) and was processed using custom algorithms for filtering outliers and rasterization into a 2.5 cm raster grid (DEM). Analysis of differences between the two high spatial resolution DEMs revealed changes in the landscape due to natural (erosion/deposition) and anthropogenic (farming activities) factors. Specifically, for ephemeral gully analysis, morphological features in the form of headcut position and size, channel incision, sinuosity, lateral expansion, and depositional patterns were easily identified. Findings of this study shed light on potential pitfalls inherent to the utilization of off-the-shelf commercial software packages for such fine scale multi-temporal analysis, describe the need for standardization of procedures that assure accurate erosional response amongst different studies, and support the generation of accurate datasets critical in advancing our understanding of ephemeral gully processes needed for improved model development and validation.
How to co-produce climate services in collaboration with users? Insights from a story map development process.
Authors: Vollstedt Bente , Koerth Jana , Vafeidis Athanasios
Published: March 2020

The actual use of climate services depends on the identification of real user needs and their integration into the service. Thus, for the production of climate services user involvement is a vital component. Descriptions of practical approaches in the scientific literature are rare but necessary in order to gain better user insights and to improve the user-provider interface. In the frame of the ERA4CS project EVOKED, we apply the user-centered Living Lab approach to develop climate services with the objective to support the coastal adaptation process in Flensburg, a city vulnerable to coastal flooding due to sea-level rise. The aim is to transform climate information into valuable and useable climate services for users. In the beginning of the project we identified the climate service user needs of the community. Thereafter, we co-produced a web-based story map in collaboration with the users, as an information tool for the general public. The story map includes information on sea-level rise and its potential impacts and displays information on relevant adaptations options. For the production process of the story map we started with a compilation phase by drafting a first version of the story map from the providers’ perspective, followed by a demonstration and online feedback phase with user involvement. Based on the received feedback, we adjusted the story map to meet user needs. Results showed the need for clearer visualization of e.g. exposed locations in the city and more detailed information on adaptation measures. Preliminary findings indicate that the active provider-user interaction for the climate service may lead to long-term adaptation action.
Evaluating future beach reduction in a changing climate: Methodologies and uncertainties.
Authors: Agulles Miguel , Jordà Gabriel
Published: March 2020

In recent years there have been endless coastal actions that have substantially modified the equilibrium conditions of much of the coastline. This fact, along with an unprecedented coastal population growth and the projected sea level rise, make beaches a particularly vulnerable region to climate change impacts. In particular, there is a clear need to quantify the reduction of the beach area due to the combination effects of the sea level rise and changes in the waves in the swash zone, under different future climate scenarios.

In this work different methodologies are developed to estimate the retreat of the coastline and to quantify the associated uncertainties. The methodologies have been applied to three beaches of the Balearic Islands, which have been continuously monitored during the last decade. The different methodologies imply the use of models to propagate the waves from deep waters to shallow depths and to compute wave runup. The results are compared to simpler approaches based on empirical formulations that provide a cost-effective solution to cover large domains. All the different approaches are validated with coastal wave recorders (AWACs) and data from cameras from which wave runup is estimated. Furthermore, a sensitivity analysis has been performed to assess the impact of uncertainties in the beach bathymetry.

The first results show that under the RCP8.5 scenario, the expected coastline retreat under mean conditions would be of ~22 ± 5 meters at mid-century. Considering extreme waves conditions, the retreat would reach ~40 ± 5 meters.

It is worth mentioning that the three studied beaches have a very different exposure, granulometry and maritime climate, and in spite of that, the estimated uncertainty level is relatively low (~10-25%) in all of them. Therefore, the proposed methodologies along with their uncertainty analysis, might be extrapolated to any sandy beach with a reasonable high degree of accuracy. 
Interseasonal impact of Siberian snow cover formation rate on the baroclinicity and wave activity over Northern Eurasia
Authors: Martynova Yuliya V. , Krupchatnikov Vladimir N.
Published: March 2020

Climate changes can cause a change of pattern of the atmospheric interaction between polar and middle latitudes, which can cause a change in the cyclone formation regime, which in turn can provoke extreme and hazardous phenomena intensification. Therefore, it is essential to understand the nature of the atmospheric interaction in question clearly.

Due to climatic features, it is precisely in the Siberian part of Eurasia that the most extensive snow cover forms, causing significant radiation cooling in this territory. The snow cover area, and consequently the intensity of radiation cooling, can vary significantly from year to year. It can make a significant impact on the interaction of the troposphere and lower stratosphere of middle and Arctic latitudes not only during the establishment of snow cover but also in the following winter season. Knowledge of the features and patterns of the manifestation of the influence of local disturbances (arising on the surface in the autumn due to the formation of autumn snow cover) on the atmospheric conditions of the following winter can be used as additional information when making seasonal weather forecasts.

The present study aims to assess the response of the troposphere and lower stratosphere over Northern Eurasia during the autumn-winter period to a rate of the snow cover formation in Siberia.

We separated the years with the sharp intensive and smooth slow snow cover formation. We analyzed for them the baroclinicity index and its components (the zonal and meridional potential temperature gradient and the Brent-Väisälä frequency) for various isobaric levels (up to 200 hPa), and Eliassen-Palm flux. The results obtained suggest that anomalies in the snow cover formation rate in Siberia can contribute and cause anomalies in atmospheric circulation in the autumn-winter period. However, there is no complete clarity regarding the mechanism of distribution of this influence.

This work was supported by the Russian Science Foundation grant No. 19-17-00248.
Development of a three-dimensional global circulation model for Uranus
Authors: Temel Orkun , Karatekin Özgür
Published: March 2020

In this study, we present the Uranus implementation of the planetWRF model [1]. For the determination of the radiative heat fluxes in our three-dimensional global circulation model, we make use of a simple analytic radiative model. This model is based on two-stream approximation and using a power-law scaling for the relationship between the optical depth and the pressure [2]. Preliminary results are compared to the zonal wind [3] and vertical temperature observations [4]. The effect of model's resolution, both vertical and horizontal, on the representation of the strong zonal transport in the Uranian atmosphere, is investigated. Moreover, we discuss the seasonal wind speed variations predicted by our model, assessing its potential to predict the changes in the zonal transport before and after the equinox in 2007. Possible implications for the Entry, Descent, and Landing applications are also presented. The devleoped GCM can also be potentially applied to the atmosphere of Neptune. 

[1] Richardson, Mark I., Anthony D. Toigo, and Claire E. Newman. "PlanetWRF: A general purpose, local to global numerical model for planetary atmospheric and climate dynamics." Journal of Geophysical Research: Planets 112.E9 (2007).
[2] Robinson, Tyler D., and David C. Catling. "An analytic radiative-convective model for planetary atmospheres." The Astrophysical Journal 757.1 (2012): 104.
[3] L.A. Sromovsky, I. de Pater, P.M. Fry, H.B. Hammel, P. Marcus, High S/N Keck and Gemini AO imaging of Uranus during 2012–2014: new cloud patterns, increasing activity, and improved wind measurements. Icarus 258, 192–223 (2015).
[4] Marley, Mark S., and Christopher P. McKay. "Thermal structure of Uranus' atmosphere." Icarus 138.2 (1999): 268-286.
Location of Stromboli volcano July 2019 paroxysm event based on long-range infrasound detections in several IMS stations
Authors: Matos Sandro , Wallenstein Nicolau , Marchetti Emanuele , Ripepe Maurizio
Published: March 2020

Stromboli is one of the most active volcanoes on Earth with a continuous explosive activity and persistent degassing since at least 3-7 AD (Rossi et al., 2000). Being an open conduit volcano, its spectacular basaltic explosions interspersed by lava fountains occurring every ≈10 minutes (Ripepe et al., 2002) make it probably the world's best-know and best-monitored volcano.

On 3rd July 2019 at the 14:45:43 UTC a paroxysmal explosion occurred with an ash column that rose almost 5 km above the volcano. This very strong explosive event was detected in several IMS infrasound stations, including IS42, located in the Azores islands in the middle of the North-Atlantic, at a distance of about 3,700 km.

We present the long-range infrasound detections that allowed us to locate the source based only in infrasound with an estimated error of less than 55 km from the ground truth event.

Keywords: Stromboli volcano, paroxysm, infrasound, IMS, IS42
Contrasting seismogenic behaviors on the North Anatolian Fault in the Sea of Marmara
Authors: Henry Pierre , Grall Céline , Özeren M Sinan , Özbey Volkan , Uçarkus Gülsen , Géli Louis , Ballu Valérie , Çakir Ziyadin , Ergintav Semih , Lange Dietrich , Royer Jean-Yves
Published: March 2020

Since the 1999 Izmit-Kocaeli earthquake, the Main Marmara Fault (MMF) of the North Anatolian Fault system in the Sea of Marmara has been considered at an imminent risk for a large earthquake. Land geodesy has difficulties characterizing the distribution of interseismic loading, and hence of slip deficit, on the offshore faults, and notably on the Istanbul-Silivri segment of the NAF. The need to clarify the status of offshore fault segments has motivated seafloor monitoring experiments and marine geophysical and sedimentological studies, notably in the framework of EMSO consortium and MARSITE and MAREGAMI projects. Results from cross-disciplinary projects have shown that aseismic creep, spatially correlated to active gas venting at the seafloor, occurs on the Western segment of the MMF. This segment is also capable to large earthquake ruptures such as the 1912 event. On the eastern part of the Sea of Marmara, the Istanbul-Silivri and Prince Island segments appear essentially locked. Moreover, the base of the seismogenic zone and locking depth appears to shallow (from 15-20 to 10-15 km) from west to east.

On one hand, we propose to further evaluate fault slip rates and distribution of locking ratio on individual fault segments using an elastic block model constrained by land geodesy data and marine observations (long-term fault slip rate estimates, local acoustic ranging results). On the other hand, we evaluate the temperature at the seismogenic depths by basin modelling. Results suggest that spatial variations of fault behavior in the Sea of Marmara may result from a combination of factors. First, thermogenic gas generation within the > 6 km thick sedimentary cover in the Western Sea of Marmara may contribute to unlock the shallow part of the fault by generating overpressures. Second, heterogeneity of the crust composition could be a factor as the North Anatolian Fault system follows the intra-pontide ophiolitic suture. For instance, long term post-seismic creep onland at Ismet Paşa has been related to the presence of serpentinite in the fault zone. Moreover, high-density magnetic bodies have been identified along the MMF. Third, varying thermal regimes between the Western and Eastern parts of the Sea of Marmara may account for variations in the seismogenic depths. Seafloor heat flow in the Sea of Marmara is strongly affected by sediment blanketing and basin modeling considering this process suggests that the crustal heat flow is about 20 mW/m2 higher in the eastern part than in western part of the Sea of Marmara. This difference may be explained by a more spread out crustal extension in the western Sea of Marmara.
Drought and water management in the German agricultural sector - a participatory system dynamics approach
Authors: Valencia Rodrigo , Egerer Sabine , Máñez María
Published: March 2020

Higher temperatures and changes in precipitation patterns caused by climate change may potentially affect water availability for agriculture and increase the risk of crop loss in Northeast Lower Saxony (NELS), Germany. The drought of 2018 showed that an intensification of irrigation might be a temporary solution. However, a long-term increase in water extraction, especially during drought periods, is not a sustainable solution. To assess possible water management solutions, we implement a participatory system dynamics approach, namely Group Model Building, to develop a qualitative system dynamics model (QSDM) describing the agricultural system and its relation to water resources in NELS.

The development of the QSDM seeks to understand the complexity of the interactions between agriculture and hydrological systems, recognize the stakeholders’ needs and identify risks and weaknesses of both systems. By understanding this, we expect to reinforce the adaptation process, reduce conflict and be able to suggest tailored solutions and adaptation measures. The QSDM incorporates a wide range of perceptions, as twenty stakeholders ranging from farmers, government agencies, environmental protection organizations and local water authorities were involved in the QSDM development. Their perceptions were recorded in the QSDM through individual interviews and a group workshop.

Through the QSDM, we identified and mapped the structure and connections between agriculture and the water balance. It was also possible to identify the strongest feedback loops governing both sectors as well as their influence on the current situation. The loops represent behaviors and structures, which might become unmanageable under climate change conditions. The causal loops include the different uses for the available water of the region, the impact of irrigation, the significance of crop selection and the importance of sustainable soil management.

By analyzing the system this way, we confirmed that climate change poses a risk to the region as elevated temperatures could increase the crop water demand and increase the need for irrigation. In the same way, changes in the rain patterns could affect the water balance of the region. The agricultural system has, however, potential to adapt by implementing new water management strategies such as restructuring water rights, water storage and reuse and conjunctive water use. Other measures include increasing the irrigation efficiency, changing crops and enhancing the soil quality, among others.
An investigation into the controls on fracture tortuosity in rock sequences and the impact on fluid flow in the upper crust
Authors: Forbes Inskip Nathaniel , Phillips Tomos , Bisdom Kevin , Borisochev Georgy , Busch Andreas , den Hartog Sabine
Published: March 2020

Fractures are ubiquitous in geological sequences, and play an important role in the movement of fluids in the earth’s crust, particularly in fields such as hydrogeology, petroleum geology and volcanology. When predicting or analysing fluid flow, fractures are often simplified as a set of smooth parallel plates. In reality, they exhibit tortuosity on a number of scales: Fine-scale tortuosity, or roughness, is the product of the small-scale (µm – mm) irregularities in the fracture surface, whereas large-scale (> mm) tortuosity occurs as a result of anisotropy and heterogeneity within the host formation that leads to the formation of irregularities in the fracture surfaces. It is important to consider such tortuosity when analysing processes that rely on the movement (or hindrance) of fluids flowing through fractures in the subsurface. Such processes include fluid injection into granitic plutons for the extraction of heat in Engineered Geothermal Systems, or the injection of CO2 into reservoirs overlain by fine-grained mudrocks acting as seals in Carbon Capture and Storage projects.

Although it is generally assumed that tortuosity is controlled by factors such as grain size, mineralogy and fracture mode, a systematic study of how these factors quantitatively affect tortuosity is currently lacking. Furthermore, in anisotropic rocks the fracture orientation with respect to any inherent anisotropy is also likely to affect tortuosity.

In order to address this gap, we have induced fractures in a selection of different rock types (mudrocks, sandstones and carbonates) using the Brazil disk method, and imaged the fracture surfaces using both a digital optical microscope and X-ray Computed Tomography. Using these methods we are able to characterise both the fine-scale (roughness) and large-scale tortuosity. In order to understand the effect of fracture orientation on tortuosity we have also analysed fractures induced at different angles to bedding in samples of a highly anisotropic mudrock taken from South Wales, UK. Results indicate that fine-scale tortuosity is highly dependent on the fracture orientation with regards to the bedding plane, with fractures normal to bedding being rougher than those induced parallel to bedding. Finally, in order to measure the effect of tortuosity on fluid flow, we have carried out a series of core flooding experiments on a subset of fractured samples showing that fracture transmissivity decreases with increasing tortuosity.
Strain localization processes at a magma-starved ridge: from micro-scale to macro-scale
Authors: Bickert Manon , Cannat Mathilde , Tommasi Andréa , Jammes Suzon , Lavier Luc
Published: March 2020

The easternmost part of the Southwest Indian Ridge (SWIR) is characterized by a very low melt-supply. Magma is focused along axis at discrete volcanic centers, leaving large portions of the seafloor where plate divergence is accommodated by large offset normal faults, also called detachment faults. These faults exhume mantle-derived samples on the seafloor. Microseismicity indicates a brittle lithosphere up to 25 km thick (Schlindwein & Schmid, 2016). These axial detachments require effective localized weakening in the shallow lithosphere to allow for large displacements along the fault and significant flexure of the footwall plate.

Here, we focus on the strain localization processes that operate in the deep axial lithosphere, in the absence of magma and prior to hydrothermal alteration. Using 99 dredged samples of partially serpentinized peridotites, we show that the primary mineralogy records heterogeneous high stress deformation that is detected in all samples to variable degrees. This deformation combines plastic and brittle mechanisms and is characterized by the development of extensively recrystallized anastomozing microshear zones. Estimates of temperature (800-1000°C) and deviatoric stresses (80-270 MPa) during deformation are derived, respectively, from pyroxene thermometry and olivine grain size piezometry. We show that strain localization is initially controlled by stress concentrations due to the contrast in rheology between orthopyroxene (strong, primarily brittle with microfractures, kinks and local dynamic recrystallization) and olivine (weak, primarily plastic with undulose extinction, subgrains, dynamic recrystallization, but also kinks and localized microfractures). We propose that these microstructures reflect the imprint of an episode of lithospheric deformation that formed the root of the axial detachments and that the resulting grain size reduction helps localize strain at the base of the lithosphere. This weakening mechanism plays an essential role in the development of flip-flop detachments in this area (Bickert et al., 2020). It may also operate in other magma-starved contexts such as ocean-continent transitions, where lithospheric deformation occurs without a significant melt supply.
Land degradation by soil erosion and sedimentation within Sarata catchment, Republic of Moldova
Authors: Vacula Silvia , Niacsu Lilian , Secu Cristian , Vasiliniuc Ionut
Published: March 2020

Land degradation by geomorphological processes (soil erosion, gully erosion, landslides and

sedimentation) represents an important environmental threat all over the Republic of Moldova.

The main causes are related to the favourable natural conditions such as friable lithology,

typically hilly fragmentation or climatic aggressiveness on the background of a sustained human

impact developed in the last two centuries. Despite the widespread soil and water conservation

measures that have been implemented during the soviet period, following the Agricultural Real

Estate Act applied in 1991, a revival of these processes is easier to observe especially by means

of floodplains aggradation. Under these circumstances, our study aims to assess the

sedimentation rates on the floodplains and reservoirs and to establish the source area of the

eroded sediments as well as the responsible process. Based on field campaigns, we took

representative in-situ soil / sediment samples from floodplains and reservoirs all over the Sarata

catchment, including wind-blown samples from the intefluvial ridges. The laboratory analyses

consisted of physical and chemical features such as: weight, apparent density, texture, ph,

electrical conductibility, total organic carbon, inorganic carbon, organic matter, inorganic

nitrogen (N), total phosphorus (P), total potassium (K) and other macro elements (i.e. Na+,

Mg2+, Ca2+, and Cl-). The preliminary results show that the soil erosion remains an important

process not by quantity but by quality. This is related also to the widespread high efficiency of

gully erosion control measures that have been implemented. A secondary role, most often

neglected, is held by wind erosion
Managed peatlands as novel ecosystems
Authors: Jurasinski Gerald , Beyer Florian , Günther Anke , Gutekunst Cordula , Huth Vytas , Koebsch Franziska , Köhn Daniel , Koch Marian , Liebner Susanne , Unger Viktoria
Published: March 2020

Although peatlands cover only about 3% of the land surface of the Earth they store approx. 42% of all soil carbon, if not considerably more, as newest model approaches suggest. Only a minor fraction of all peatlands (5%) is drained, making up a total of 0.15% of the land surface. However from this small land area approx. 5.5% of the global anthropogenic CO2 emissions derive. Therefore, rewetting peatlands on a massive scale is seen as a viable option to decrease greenhouse gas (GHG) emissions and to create GHG sinks in the long run. 

Our understanding of the ecological and biogeochemical functioning of rewetted peatlands is limited, and especially limited when regarding fen peatlands, which are not even well understood in the pristine state. Thus, there is strong demand to investigate the ecological functioning of these ecosystems.

All peatlands that are not pristine anymore, are managed peatlands, regardless of wether they are still used, abandoned, or rewetted/restored. To ask the right questions regarding the ecological functioning of these systems, it is essential to acknowledge managed peatlands as novel ecosystems. The „novel ecosystem“ approach has been developed primarily to address the effect of invasive species or climate change on biodiversity and ecological functioning. „Novel“ ecosystems result as a consequence of human activity but don’t need ongoing human intervention to maintain the novel state. 

In my talk I will argue that understanding managed peatlands as novel ecosystems is essential to a proper investigation of their ecological and biogeochemical functioning. The argument will be based on the results of several recent research projects in managed temperate peatlands focussing on, inter alia, short-term and long-term vegetation development, GHG emissions and microbial community development.
A graphical method to interpret how incision thresholds influence topographic and scaling properties of landscapes
Authors: Theodoratos Nikos , Kirchner James W.
Published: March 2020

Theoretical analysis of the governing equations of numerical models can reveal relationships between topographic properties, such as drainage area, slope, and curvature, in simulated landscapes. These relationships are testable predictions; they can diagnose whether real-world landscapes could potentially arise from similar mechanisms. For example, the stream-power incision model is consistent with drainage area and slope data that plot as straight lines on logarithmic axes.

Here we graph theoretical relationships between topographic curvature and the steepness index, which depends on drainage area and slope. These relationships plot as straight lines for steady-state landscapes that have evolved according to a model that combines stream-power incision, linear diffusion, and uplift. Further, they link topography (drainage area, slope, and curvature) to characteristic length scales of the landscape, which depend on the competition between the processes of incision, diffusion, and uplift.

Adding an incision threshold to the model changes the relationship between the steepness index and topographic curvature. We examine these changes graphically and we show that they shed light on how incision thresholds influence topographic and scaling properties of landscapes. Specifically, we present a graphical method that consists of plotting steepness index–curvature lines and of tracing their intersections with each other and with the coordinate axes. This simple method reveals both how topography and process competition are influenced by the incision threshold, and how these influences vary within a given landscape and across different landscapes.
The hidden CO2 – The occurrence, distribution and composition of fluids in various salt minerals
Authors: Strauch Bettina , Zimmer Martin , Zirkler Axel
Published: March 2020

Fluid inclusions are voids enclosed in the rock matrix and contain, depending on their origin and development, various amounts of gaseous, liquid or solid phases. Depending on their occurrence within the crystalline structure or in healed micro-fractures, primary and secondary inclusions can be distinguished. Their characteristics are utilized in various geological settings to reconstruct rock history and fluid involvement. Fluid inclusions could also be considered to be small equivalents to large cavities. As salt is regarded a favorable host rock for the storage of natural gas and other materials in artificial caverns, knowledge on gas migration and retention is crucial.

Here, we present results of a fluid inclusion study in various salt rocks using Raman spectroscopy in addition to conventional microscopic characterization and gas analysis on whole rock samples. This approach allows for a better understanding of fluid generation and migration in different salt lithologies over geological times.

Various salt minerals (halite, sylvite, kieserite and carnallite) from an area of potential overprint of CO2-dominated gas migration were investigated. Numerous fluid inclusions exhibit chevron structure and are small sized. Large single- or two-phased inclusions are observed with irregular shapes, often indicative for leakage or necking down. Interestingly, although the CO2 concentrations in whole rock samples were high, fluid inclusions were dominated by an aqueous phase and often contain numerous daughter minerals. This suggests that CO2-rich gas is stored along distinct fractures or grain boundaries within an otherwise intact rock.
Distribution of Salt-marsh foraminifera in Jiaozhou Bay: Implications for sea-level reconstructions
Authors: Long Haiyan , Li Ziye
Published: March 2020

Salt-marsh foraminifera are routinely used as sea-level indicators since their vertical distribution is closely linked with elevation relative to the tidal frame. In this study, 106 surface sediment samples were collected across separate intertidal transects established at five micro-tidal salt-marsh situated along the coasts of the Jiaozhou Bay, western margin of the Yellow Sea, dead and live foraminifera were identified respectively. The dead population contains the mixture of both subtidal species and salt-marsh species, and all the live assemblages consist of salt-marsh species which can provide exact information of salt-marsh foraminiferal distribution. The agglutinated species present in the five marshes including Trochammina inflata, Miliammina fusca and Jadammina macrecens are all cosmopolitan species, however, the calcareous species contain numbers of endemic species, overall, dominant calcareous species included Cribrononion porisuturalis, Pseudononionella variabilis, Elphidiella kiangsuensis and Pseudogyroidina sinensis. Vertical foraminifera zonations have been recognized in Daguhe and Hongshiya marsh samples with some species occupying strict latitude range, which primarily related to elevation, however, no obvious assemblages zonations can be recognized in Nvgukou, Shanjiaodi and Yanghe marsh. We hypothesize that salt-marsh foraminifera in Jiaozhou Bay possesses potential in paleoenvironmental studies as the key indicators for monitoring Holocene sea-level and environmental changes.
Possible impacts of a hydropower reservoir on the flood hazard of an Alpine valley
Authors: Lebiedzinski Katharina , Fürst Josef , Schulz Karsten , Herrnegger Mathew
Published: March 2020

High mountain ranges are characterised by steep slopes and high precipitation rates, making Alpine catchments prone to frequent flood events. Fast runoff during heavy rainfall events, sometimes in combination with snow melt events, can cause severe damages in residential areas. Flood retention mainly depends on retention properties of the headwater catchment area and its interaction with the occurring flood regime. However, due to their special characteristics, Alpine catchments are ideal candidates for storage power plants as well. Currently, around 70 storage power plants are operating in Austria. Their large artificial reservoirs alter the flood retention properties in the upper catchment by potentially providing a higher flood peak attenuation, which of course depends on the available storage volume at the time of flooding. Since it already has been reported that climate change driven processes will increase flood intensity and frequency in Austria, it is of particular interest to understand how hydropower reservoirs alter flood dynamics and if they systematically could be used for flood retention in the future.

In this study the influence of a storage power plant on flood dynamics is shown for an example in the central Austrian Alps. The chain of analysed reservoirs is situated in the headwaters of the river Salzach, a Danube tributary. Based on observed runoff, the retention potential is analysed by comparing the possible natural flood event and the retained flood event in the catchment influenced by the storage power plant. Then its possible impact on the flood hazard downstream is investigated until the tributary drains into the Danube. 

This contribution is part of the interdisciplinary research project “Policy Coordination in Flood Risk Management” (PoCo-FLOOD), which is funded by the Earth System Sciences program of the Austrian Academy of Sciences.
Detailed simulations of snow properties and accumulation across the Antarctic Ice Sheet
Authors: Lenaerts Jan , Keenan Eric , Wever Nander , Dattler Marissa , Reijmer Carleen , Medley Brooke
Published: March 2020

Surface mass balance (SMB) represents a large uncertainty in characterizing Antarctic Ice Sheet (AIS) mass balance. Atmospheric reanalysis products, which are commonly used for AIS SMB studies, do not include small-scale snow redistribution processes even though these can be of the same order of magnitude as snow accumulation in many parts of the AIS. Therefore, a proper representation of these processes is critical to interpret local SMB and firn observations, such as from ICESat-2 repeat altimetry. In this study, we use a detailed, multi-layer snow model (SNOWPACK) forced by a global atmospheric reanalysis (MERRA-2). Firstly, we show that a new accumulation scheme, designed to better represent wind-driven snow compaction in SNOWPACK, substantially reduces simulated biases in near-surface snow density at 131 locations across the AIS. Next, we employ a distributed version of SNOWPACK to two regions on the AIS, and compare the simulation output to airborne radar and in-situ observations of SMB. Our results demonstrate that SNOWPACK can capture the timing of blowing snow events, snow erosion events, as well as observed kilometer-scale spatial SMB variability. This study illustrates the importance of using high-resolution SMB models when converting surface height (volume) observations to mass changes.
Using X-ray densitometry of carbonized wood to refine the date of past volcanic eruptions
Authors: Reinig Frederick , Guidobaldi Giulia , Nievergelt Daniel , Verstege Anne , Schweingruber Fritz , Crivellaro Alan , Wacker Lukas , Esper Jan , Büntgen Ulf
Published: March 2020

Trees that were killed and buried by volcanic eruptions can be used to date an eruption with annual or even sub-annual resolution. The detection and measurement of subfossil tree-ring widths (TRW), however, often remains challenging if the material was carbonized during the eruption. Here, we show that the application of X-ray densitometry can improve the assessment of charcoal. Measuring the wood density of carbonized trees killed by the Laacher See Eruption ~13,000 years ago, facilitates the identification of the outermost rings that were formed just before the eruption. Our results suggest that anatomical techniques should be routinely applied in the assessment of historical, archaeological and subfossil wood.
Permian sporomorphs from upper Palaeozoic succession of Southern Tuscany (Italy): new constraints for the stratigraphy and palaeogeographic setting of the Tuscan Domain
Authors: Spina Amalia , Brogi Andrea , Capezzuoli Enrico , Cirilli Simonetta , Liotta Domenico
Published: March 2020

Recent biostratigraphic, sedimentological and petrological studies in the inner Northern Apennines (Italy) permit to refine the upper Palaeozoic successions of southern Tuscany, allowing new hypothesis to frame these formations in the Permian palaeogeographical scenario of the western Mediterranean domain. The Tuscan pre-Triassic deposits, belonging to the Monticiano-Roccastrada Unit, are generally barren or scarce in term of biomineralized fossiliferous content. They were mostly affected by HP-LT to LP-HT metamorphism that, together with the limited distribution of deposits, made difficult their stratigraphic correlation.

The present study is focused on two metamorphic units (i.e. Filladi e metacalcari di Fosso della Falsacqua Formation and Filladi e quarziti del Torrente Mersino Formation) which age attribution and correlation was strongly debated in the literature.

The Filladi e metacalcari di Fosso della Falsacqua Formation (minimum estimated thickness of about 150 m), cropping out in Monte Leoni area, is mainly characterized by black to dark-grey phyllite, metasiltstones and metasandstones with dark limestone intercalations. Due to the lack of biomineralized fossil content, by lithostratigraphic correlation with other formations cropping out in Tuscany, this formation was differently assigned to late Carboniferous-early Permian or Devonian.

The Filladi e quarziti del Torrente Mersino Formation (minimum estimated thickness of about 200 m) crops out in the Boccheggiano mining area and mainly consists of black to dark-grey quartz-phyllite, quartz metaconglomerates, light-grey quartzites, green phyllites and quartzites and light-grey phyllites. This formation resulted barren of fossil content and has been differently assigned to Ordovician-Silurian, Silurian-Devonian, late Carboniferous-Permian and Triassic by lithostratigraphic correlation with other Tuscan-Sardinian successions.

In the present study, the first finding of a middle Permian well-preserved microflora adds more constrains to the age attribution of these studied formations. This new age assignment permits to correlate the investigated formations with the coheval ones belonging to southern Tuscany (i.e. Farma Formation) and Elba Island (Rio Marina Formation) characterized by a similar microfloral content. Moreover, the occurrence of Gondwana-related sporomorphs, in all the studied formations, points to a new palaeogeographic scenario of the upper Palaeozoic successions from the northern Gondwana margin. The results of this integrated study inclines to consider the fragmentation of the northern margin of Gondwana as a result of several transtensional (pull-apart) basins where different laterally-related depositional environments leaded the sedimentation of these Tuscan middle Permian formations.
Data forcing errors resulting from lack of harmonization and standardization in measurement methodologies: A comparison of soil hydrophysical data from a large EU database.
Authors: van der Ploeg Martine , Nemes Attila
Published: March 2020

Soil hydro-physical properties —such as soil water retention, (un)saturated hydraulic conductivity, shrinkage and swelling, organic matter content, texture (particle distribution), structure (soil aggregation/pore structure)and bulk density— are used in many sub(surface) modeling applications. Reliable soil-hydrophysical properties are key to proper predictions with such models, yet the harmonization and standardization of these properties has not received much attention. Lack of harmonization and standardization may lead to heterogeneity in data as a result of differences in methodologies, rather than real landscape heterogeneity. A need and scope has been identified to better harmonize, innovate, and standardize methodologies regarding measuring soil hydraulic properties that form the information base of many derived products in support of EU policy. With this identified need in mind the Soil Program on Hydro-Physics via International Engagement (SOPHIE) was initiated in 2017. Besides developing new activities that may advise future measurements, we also explore historic data and metadata and mine its relevant contents. The European Hydro-pedological Data Inventory (EU-HYDI), the largest European database on measured soil hydrophysical properties, is – to date – rather under-explored in this sense, which served as motivation for this work.

From EU-HYDI we selected those records that were complete for soil texture, bulk density and organic matter, and fitted pedo-transfer functions separately for particular water retention points (at heads of 0, 2.5, 10, 100, 300, 1000, 3000, 15000 cm) and saturated hydraulic conductivity by multi-linear regression. We then subtracted the observed retention and hydraulic conductivity values from their estimated counterparts, and grouped the residuals by measurement methodologies. The results show that there can be significant differences between different methodologies and sample sizes used to obtain the water retention and hydraulic conductivity in the laboratory. The results thus show that the EU-data that may underlie large scale modelling may introduce errors in the forcing data that are attributed to a lack of harmonization and standardization in currently used measurement protocols.
Monitoring of rock glacier flow velocity variations using imagery, laser scan data and ground-based interferometric synthetic aperture radar (GBInSAR) at the Finstertal reservoir (Austria)
Authors: Fey Christine , Kuschel Erik , Amabile Anna Sara , Straka Wolfgang , Zangerl Christian
Published: March 2020

Rock glaciers are geomorphological phenomena of mountain permafrost which slowly move downslope as a consequence of the ice deformation. During the last few decades, many rock glaciers in the Alps are showing an increase of flow velocities which is most probably caused by climate change. However, the factors influencing the flow velocities (e.g. air temperature, meltwater infiltration, internal rock glacier characteristics) are not fully understood. Data about the annual, inter-annual and diurnal rock glacier flow velocities are essential to understand the influence of climatic factors on rock glaciers.

This study focused on the Finstertal rock glacier, located in the Eastern Alps, where flow velocities are reconstructed since the 1970s based on aerial imagery, airborne and terrestrial laser scan data. Since 2014, a terrestrial laser scanning (TLS) based monitoring is implemented. The maximum flow velocities of the Finstertal rock glacier increased from 0.1 m/year (time period 1970-1997) to 1.4 m/year (time period 2015-2016) and is currently about 1.3 m/ year (time period 2018-2019).

The accuracy of aerial imagery and laser scan data is in the range of centimetres and well suited to analyse the annual variability of rock glaciers. Imagery and laser scan data are not suited for shorter time intervals, where the absolute displacement of a rock glacier is smaller than the measurement accuracy. Consequently, for the understanding of interannual and diurnal variations in rock glacier flow velocities, other measurement methods are needed. Ground-based interferometric synthetic aperture radar (GBInSAR) is able to detect spatial deformations in the range of sub-centimeters.

Therefore, to get a more detailed understanding of the rock glacier flow velocity variations, a GBInSAR was installed on Finstertal hydroelectric dam to measure the rock glacier flow velocities between October to November 2019. In this study, preliminary results on diurnal flow velocity variations of Finstertal rock glacier, based on GBInSAR, are presented, and compared to annual variations derived from aerial imagery and laser scan data.
Internet of Things Technologies for the Efficient Collection of Hydrological Measurement Data
Authors: Drost Sebastian , Speckamp Jan , Hollmann Carsten , Malewski Christian , Rieke Matthes , Jirka Simon
Published: March 2020

The collection of hydrological measurement data comprises a broad range of challenges beyond the development and deployment of sensing devices. Especially the transmission of the collected (raw) data to central data servers may be a challenging task depending on the available infrastructure.

In our presentation we will discuss the applicability of Internet of Things (IoT) technologies to enable a lightweight data collection workflow relying on the Message Queuing Telemetry Transport (MQTT) protocol as well as the SensorThings API standard of the Open Geospatial Consortium (OGC). These standards are especially optimised to reduce communication overheads, to be viable via resource constrained communication links, and to support a seamless plug-and-play integration of new measurement devices.

As part of this presentation, we will introduce the communication patterns and messages used by the data collection mechanism. This will be combined with a discussion how these IoT standards can be coupled to existing sensor hardware and which types of communication link can be used. Afterwards, we will also discuss the design of a data management server that integrates the collected measurement data. This comprises on the one hand connectors to the IoT data streams but on the other hand also data management and storage functionality, as well as interoperable interfaces for sharing the collected data.

For the validation of the presented concept, a pre-operational deployment at the Wupperverband, a regional water management association in Germany, will be shown. This comprises not only the practical experiences gained during the operation but also recommendations on future challenges such as semantic interoperability (e.g. vocabularies) as well as the efficient management of large amounts of incoming time series data (e.g. via dedicated database concepts).

Thus, in summary our contribution aims to contribute to the discussion on how IoT technologies may help to facilitate the collection of hydrological measurement data and to support the sharing of such data.