bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of the use of drainage-/ infiltration systems in the Pleistocene uplands of the Netherlands
Authors: de Wit Janine A. , Bartholomeus Ruud P. , van den Eertwegh Gé A.P.H. , van Huijgevoort Marjolein H.J.
Published: March 2021

The Netherlands is a low-lying, flood prone country, located in a delta. Most Dutch agricultural fields are drained to quickly get rid of excess water to increase crop production. Additionally, the freshwater demand of different sectors (agriculture, industry, drinking water) increases, causing an increased pressure on the groundwater system. The combination of fast drainage and increased use of groundwater for human activities led to declining groundwater tables in the Dutch Pleistocene uplands. Given the changing climate resulting in prolonged dry periods, solutions for water retention are needed to decrease the pressure on the groundwater system to guarantee the future water supply for different sectors.

One of the solutions could be to modify the current drainage systems to drainage-infiltration (DI)-systems with a dual purpose. First, the DI-system stores water during (heavy) rainfall in the soil, but if the risk of flooding increases, the DI-system discharges water. Second, (external) water is actively pumped into the drainage network to raise groundwater tables (subirrigation). Through efficient use of the available external water source (treated waste water, industrial waste water, surface water or groundwater) the pressure on the groundwater system reduces.

We focus on the data and model results of several field experiments using subirrigation conducted in the Dutch Pleistocene uplands (± 2017-2020). The effects of subirrigation on the groundwater table and soil moisture conditions will be shown, including water supply rate and hydrological boundary conditions. We also provide both the set-up and results of field scale model simulations (SWAP; Soil-Water-Atmosphere-Plant model) to i) quantify the impact of subirrigation on all components of the (regional) water balance (including transpiration, drainage and groundwater recharge), ii) quantify crop yields, and iii) optimize the configuration and management of subirrigation systems for different soil types, hydrological boundary conditions, and climate scenarios.  
Geodiversity of proglacial areas and implications on abiotic ecosystem services
Authors: Bollati Irene Maria , Viani Cristina , Masseroli Anna , Mortara Giovanni , Testa Bruno , Tronti Gianluca , Reynard Emmanuel , Pelfini Manuela
Published: March 2021

Proglacial areas, defined as the areas left free from glaciers since the Little Ice Age, are open-air laboratories to study the effects of climate change on high mountain environments. Their different abiotic features (i.e. geodiversity) depend mainly on the bedrock characteristics, the type of glaciers acting in the areas and the morphometry of their hydrographic basins, which influence the geomorphic dynamics (i.e., geomorphodiversity). From this, it could derive a different response of glacier forefields to deglaciation and particular evolutionary trends. Hydrological elements and dynamics are particularly variable (i.e. hydrogeodiversity), especially in terms of proglacial lakes diversification, having effects down-valley, even far from the strict proglacial area, and also in term of potential natural hazards. Moreover, geodiversity of proglacial areas may have implications on other types of “diversity”. After the glacier retreat, glacier forefields are, in fact, characterized by soils development and vegetation settlement. In particular, soils characterized by different ages and by different degree of development coexist over short distances (i.e. pedodiversity), functioning also as a support for living organisms. Biotic components gradually colonize such areas, from the pioneer to the late-successional species, bringing varied species along the proglacial plains (i.e. biodiversity). All these aspects can be discussed in the perspective of the abiotic ecosystem services (i.e. regulating, supporting, provisioning, and cultural) provided by glacier forefields. Regulating services are related to both atmospheric and terrestrial processes, including natural hazard regulation. Supporting services deal mainly with habitat provision and soils development. Provisioning services include both material (freshwater, building materials) and immaterial (i.e. tourism) resources. Finally, cultural services, that are the most numerous, take into account, among the others, the spiritual and historical meaning, the geohistorical importance for the Earth Sciences development, the educational and geotourism-related opportunities, and the landscape benefit effects. Considering all these aspects, and the intense dynamics proglacial areas are affected by, which will be illustrated through examples mainly from the European Alps, it emerges the importance of a careful monitoring and management of such areas, hopefully through an even more holistic approach.
The numerical reconstruction of three past eruptions at Gede volcano (Indonesia)
Authors: Tennant Eleanor , Jenkins Susanna , Winson Annie , Widiwijayanti Christina , Gunawan Hendra , Haerani Nia , Kartadinata Nugraha , Banggur Wilfridus , Triastuti Hetty
Published: March 2021

Understanding past eruption dynamics at a volcano is crucial for forecasting the range of possible future eruptions and their associated hazards and risk. In this work we reconstructed pyroclastic density currents and tephra fall from three eruptions at Gede volcano, Indonesia with the aim of gaining further insight into past eruptions and identifying suitable eruption source parameters for future hazard and risk assessment. Gede has the largest number of people living within 100 km of any volcano worldwide, and has exhibited recent unrest activity, yet little is known about its eruption history. For pyroclastic density currents, we used Titan2D to reconstruct geological deposits dated at 1200 and c. 1000 years BP. An objective and quantitative multi-criteria method was developed to evaluate the fit of over 300 pyroclastic density current (PDC) model simulations to field observations. We found that the 1200 years BP geological deposits could be reproduced with either a dome collapse or column collapse as the generation mechanism although a relatively low basal friction of 6 degrees would suggest that the PDCs were markedly mobile. Lower basal frictions may reflect the occurrence of previous PDCs that smoothed the path, reducing frictional resistance and enabling greater runout for the reconstructed unit. For the 1,000 years BP PDC, a column collapse mechanism and higher basal friction was required to fit the geological deposits. In agreement with previous studies, we found that Titan2D simulations were most sensitive to the basal friction; however, we also found that the internal friction – often fixed and considered of low influence on outputs - can have a moderate effect on the simulated average deposit thickness. We used Tephra2 to reconstruct historic observations of tephra dispersed to Jakarta and other towns during the last known magmatic eruption of Gede in 1948. In the absence of observable field deposits, or detailed information from the published literature, we stochastically sampled eruption source parameters from wide ranges informed by analogous volcanic systems. Our modelling suggests that the deposition of tephra in Jakarta during the November 1948 eruption was a very low probability event, with approximately a 0.03 % chance of occurrence. Through this work, we exemplify the reconstruction of past eruptions when faced with epistemic uncertainty, and improve our understanding of past eruption dynamics at Gede volcano, providing a crucial step towards the reduction of risk to nearby populations through volcanic hazard assessment.
A model for off-fault plastic poroelastic deformation and its effects on permeability
Authors: Yalcin Bora , Zielke Olaf , Mai Martin
Published: March 2021

Fractured reservoirs comprise finite or discrete fracture networks; if these are conductive, they
form heterogeneously distributed high-permeability streaks. These are generally referred as
fracture corridors. Unless they occur as joint swarms, fracture corridors are simply seismic or sub-
seismic fault zones with connected fractures in the near-fault damage zone. Several studies
document the decrease in rock-matrix permeability adjacent to the fault surface, within the
damage zone. Although the damage zone creates fracture connectivity and high permeability
anisotropy for reservoirs, the matrix fracture feeding mechanism is related to matrix permeability
generally described by a transfer function. This transfer function accounts for fracture properties
(i.e. fracture density, length and connectivity), relative fluid mobilities, imbibition and reservoir
properties (i.e. matrix permeability). Commonly, the matrix permeability for all transfer functions
is considered in terms of a representative rock type permeability. However, observational
evidence and our numerical model show that slip induced deformation causes significant strain on
matrix in vicinity to the fault surface causing a permeability decrease in the matrix.

In this study, we present a new approach to model strain in a porous medium and related
permeability changes due to stress perturbation from slip around pure strike slip faults. The fault
length is used to scale the amount fault slip. For given/computed dislocation (slip) the off-fault
strain is then calculated to derive porosity and permeability changes. In our study we propose an
off-fault plastic-poroelastic deformation model for any known fault length and known rock
mechanical and petrophysical properties of the surrounding material. Our modeling technique will
help to better quantify fault transmissivity in geo-reservoirs.
Post-processing of NWP rainfall to facilitate blending with advection forecasts 
Authors: Brier Robert , Yu Bofu , Seed Alan
Published: March 2021

Good short-term predictions of rainfall over a few hours can be made through advecting the current radar image. Numerical Weather Prediction (NWP) extrapolates high resolution models of the atmosphere.  Advection forecasts are useful for a range of 0-3 hours and NWP forecast are generated up to days in advance. The question is to combine the two to optimize the forecast for the 3-24 hour period when information from the initial radar field may still usefully correct the NWP.

To achieve this blending, several questions need to be addressed. Firstly, the reliability of both types of the forecasts needs to be estimated. The reliability of advection forecasts is, to some degree, answered by Short-Term Ensemble Prediction Systems (STEPS) through creating ensembles of forecasts. This can also be applied to NWP’s though the size of the datasets involved in this makes it unwieldy.

Furthermore, NWP forecast rainfall has systemic biases, underestimating the area of rainfall and skewing the probability distribution of rainfall rates at each pixel to the right, overestimating the maximums. Post processing of the NWP rainfall is done so the structure more accurately represents real rain fields.

Even with a post-processed NWP there remains the smoothing issue: if the advection and NWP forecasts locate the storm front at different places then blending is smoother than either, decreasing the variance in rainfall across the domain. Thus, we also consider how the real time radar image may be used to correct the NWP forecast in space and time to mitigate this smoothing effect.
Dynamics of methane seepage at Leirdjupet Fault Complex (SW Barents Sea) since last deglaciation and possible future scenarios
Authors: Argentino Claudio , Waghorn Kate , Vadakkepuliyambatta Sunil , Polteau Stéphane , Bünz Stefan , Panieri Giuliana
Published: March 2021

Methane emissions from Arctic continental margins may increase due to global warming. Present-day ocean fluxes seem to provide a minor contribution to the atmosphere methane pool, but large uncertainties still remain on the magnitude of future emissions from methane seeps and gas hydrate-bearing sediments. The Barents Sea is a natural laboratory to study the evolution of methane seeps in relation to climate change, as it recorded several phases of ice-sheet advance and retreat during the Pleistocene. Glaciations and its concurrent denudation of the Barents Sea influenced the subsurface, causing reservoir expansion and fracturing, thereby driving hydrocarbon (mostly gas) migration which resulted in a sustained regional fluid flow system. New data from this area can shed light on future response of other high-latitude continental shelves worldwide. Here, we present reconstructed methane emission dynamics at Leirdjupet Fault Complex (LFC), SW Barents Sea, since last deglaciation (occurred after ~19 cal Ka BP). The geochemical composition of sediment cores indicate prolonged methane emissions, which started after 14.5 cal Ka BP. Geochemical proxies for anaerobic oxidation of methane in the sediment (barium, calcium and sulfur enrichments, isotopic composition of foraminifera) indicate an overall decrease in seepage intensity over the Holocene toward present-day conditions. Methane-derived authigenic carbonates with aragonite mineralogy and heavy δ18O signature recorded an episode of gas hydrate destabilization in this region. Paleo-hydrate stability models suggest that this event was triggered by the influx of warm Atlantic water and isostatic uplift linked to the retreat of the Barents Sea Ice Sheet. Present-day distribution of methane seeps at LFC is strongly linked to underlying faults. Methane hydrates are stable in the southern part of the investigated seepage area and might respond to a future increase in bottom water temperatures.
Volcanic supersonic jets: an experimental study of the effect of particles on the shock cell structure and acoustic emissions.
Authors: Panunzi Stefano , Taddeucci Jacopo , Cigala Valeria , Kueppers Ulrich , Palladino Danilo Mauro , Peña Fernández Juan José , Scarlato Piergiorgio , Sesterhenn Jörn
Published: March 2021

Explosive volcanic eruptions eject a mixture of gas and pyroclasts into the atmosphere at a range of velocities. Directly above the vent, in the gas-thrust region, a supersonic jet may be generated that strongly controls the eruptive dynamics. To improve our quantitative understanding of volcanic supersonic jets, the effect on particles within them, and their acoustic emission, we have performed small-scale explosive eruptions in the laboratory using a shock-tube. The shock-tube is composed of 3 parts, a bottom (5.6 m long, elevated pressure) and a top (48mm long, ambient pressure) plexiglass cylinder (5 mm inner diameter), separated by an electrovalve.

We have run experiments using ambient air as gas and sand, with diameter between 0.1 and 0.3 mm, as particles. The gas volume was fixed while the pressure ratio (the shock-tube reservoir to ambient pressure ratio) was varied from about 4 to 8.4 to obtain supersonic flows. During the experiments, the jet was recorded with a high-speed camera operating at 34660 fps, and the resulting noise acoustic emission with microphones (6 Hz-140 kHz; 1000 kfps) positioned at 90° from the jet axis.

Among the acoustic signals produced by a supersonic jet (jet noise) we have particularly focussed on the broad-band shock noise (BBSN) that is emitted by the interaction between shock cells and the turbulence in the jet. We estimated the jet velocity using an acoustic model based on the identification of the peak frequency of the BBSN. We also identified the BBSN frequency and its variation over time by applying the complex Morlet wavelet transformation. As expected, the BBSN frequency is inversely proportional to the gas velocity. Concerning the video recording, we analysed the shock cells behaviour and their temporal oscillation due to the presence of particles. Finally, the particle ejection rate was calculated in every video frame.

We found that the acoustic signal and shock cells are influenced by the presence of particles. In fact, fluctuations in particle concentration are well visible and decelerate the flowing gas. As a consequence, there is a temporary decrease of the stand-off-distance between the vent and the first shock-cell and concurrent rise of the BBSN frequency. We noticed, in some cases, that the shock-cells disappear during a short time interval. The BBSN frequency and the stand-off-distance behaviour over time follow the oscillation of the particle ejection rate confirming their sensitivity to particle load variation.

The future prospectives of this embryonal study could lead to new instruments for determining either the amount of pyroclasts inside the volcanic jets and their exit velocity on the basis of the recorded acoustic signals.
Quantifying vertical deformation of salt marsh substrates and their recovery during and after storm surge inundation
Authors: Brooks Helen , Moeller Iris , Spencer Tom , Royse Katherine , Price Simon , Kirkham Matt
Published: March 2021

Salt marshes are globally-distributed, intertidal wetlands. These wetlands provide vital ecosystem functions (providing habitats, filtering water and attenuating waves and currents) that can translate into valuable ecosystem services. Alongside the existence of suitable horizontal accommodation space, the ability of the salt marsh platform to accrete or increase in elevation at a rate commensurate with current and projected future rates of sea-level rise is critical to ensuring future saltmarsh functioning.

While several studies have assessed whether marsh surface and subsurface processes can keep pace with sea-level rise, few have measured whether, and to what extent, a marsh substrate may consolidate during a storm surge and whether such deformation is permanent or recoverable. This is of key importance given that the frequency and/or magnitude of storm surges is expected to change over the next few decades in some locations. We apply strictly-controlled oedometer tests to understand the response of salt marsh substrates to an applied normal stress (such as that exerted by a storm surge). We compare sediment samples from Tillingham marsh, eastern England, where the sediment is clay/silt-dominated, to samples from Warton marsh, Morecambe Bay, North West England, where the sediment is sand/silt-dominated.

This research provides, for the first time, insight into the response of two compositionally-different UK marsh substrates to the application of normal stress, such as that induced by hydrostatic loading during extreme inundation events. We demonstrate that both the expected magnitude of axial displacement and the potential to recover vertical deformation after the event are affected by the particle size distribution and the void ratio, as well as past stress conditions on the marsh (particularly as a result of desiccation). The potential for irrecoverable vertical deformation in response to storm surge loading has not previously been identified in salt marsh studies.

The results of this research will improve the ability of future models of marsh geomorphological evolution to better represent these dynamic responses and their implications for the provision of ecosystem services. This research also challenges existing studies which often do not fully parameterise these dynamic responses when considering salt marsh morphodynamics.
Coupling GIS and Machine Learning for the quantitative assessment of geomorphodiversity
Authors: Melelli Laura , Petrelli Maurizio , De Blasio Claudio
Published: March 2021

The aim of this work is to use machine learning methods coupled with GIS to evaluate the Geomorphodiversity Index (GmI).

The starting assumptions are that:

-          the geomorphodiversity or the variety of landforms reflects not only the geomorphological processes but the geological component too.

-          The numerical assessment is preferable to have a spatial distribution of the geomorphodiversity, being an objective and repeatable procedure and allowing for the comparison of areas in different geographical contexts.

-          The digital data and in particular the Digital Elevation Models, can define the topographic attributes necessary to gain the quantitative index without taking into account the traditional geomorphological maps. The topographic attributes reveal and summarize the presence and the efficiency of the driving forces that shape the Earth surface. The drainage density could fill the gap on the flat areas where the topographic attributes failed (for medium horizontal resolution values).

Trying to do an unsupervised clustering approach a K-Means and Mini-Batch K-Means for "partitional" clustering and Agglomerative Clustering for "hierarchical" clustering algorithms have been used with Anaconda (an open-source software distribution platform used for data analysis and specifically, Spyder was used as IDE -Integrated Development Environment- and Python 3.7 as a programming language) coupled with ArcGIS 10.1 © ESRI software. The research is split in three different steps: the selection of the data into ArcGIS, managing, analysis and clustering of the dataset with Python, reclassification of the data and comparison with the GmI already known in the literature in ArcGIS.

The test area is the Umbria region (central Italy) where the GmI derived from a simple GIS analysis is already available.

The advantages of the unsupervised method are that:

-          no weight was previously assigned to the individual typographic parameters.

-          Calculation times are extremely short.

-          The results are similar but more accurate than GIS analysis alone.
Paroxysmal Deccan Eruptions linked to End-Cretaceous Mass Extinction
Authors: Adatte Thierry , Keller Gerta , Spangenberg Jorge E. , Mateo Paula , Punekar Jahnavi , Monkenbusch Johannes , Thibault Nicolas , Abramovich Sigal , Schoene Blair , Eddy Michael P. , Samperton Kyle , Khadri Syed F.R.
Published: March 2021

The Chicxulub impact in Mexico and Deccan volcanism in India are both linked to the end-Cretaceous mass extinction but the relative timing of the impact, volcanic eruptions, and environmental changes remain controversial, precluding a full assessment of their respective roles. Mercury anomalies within the stratigraphic record have recently been proposed as atmospheric fallout of continental large igneous provinces (LIPs), and these anomalies are associated with all five major mass extinctions in Earth’s history. If this proxy is robust, it could provide a record of volcanism directly correlated to mass extinctions and in the case of the End-extinction, the Chicxulub impact. To test this hypothesis, we analyzed mercury in the late Maastrichtian from the base of C29r to the Cretaceous-Paleogene boundary (KPB) n the astronomically tuned Elles section in Tunisia, and correlate this chemostratigraphic record with recent high-precision U-Pb geochronology of Deccan volcanism. Our results support that Hg is a robust indicator of LIP volcanism, and directly links Deccan volcanism to rapid global climate changes, ocean acidification and increasing environmental stress during the last 320-340 kyr of the Maastrichtian. Furthermore, our time-resolved Hg record and U-Pb resolved eruption volumes reveal paroxysmal volcanic eruptions (~30% by volume) during the final 35 kyr leading up to the KPB mass extinction.
2003-2005 intra-eruptive  deformation at Soufrière Hills Volcano (Montserrat) modulated  by volcano-tectonics and weak crustal rocks  
Authors: Gottsmann Jo , Flynn Molly , Hickey James
Published: March 2021

Identifying driving mechanisms behind volcano deformation is one the key challenges of volcanology. Many geodetic models rely on simplified assumptions on source shape and the mechanical behaviour of surrounding rocks. However, geochemical, petrological and geophysical data illustrate complex architectures of sub-volcanic plumbing systems and crustal rocks. Mechanical heterogeneities fundamentally influence the stress vs. strain relationship and therefore require detailed analysis beyond the isotropic, homogenous, and elastic (IHE) half-space approximation embodied in traditional models.  
Here, we invert intra-eruptive ground displacements recorded between 2003-2005 on Montserrat to shed light on the magmatic plumbing system of Soufrière Hills Volcano.  Incorporating 3-dimensional crustal mechanical and topographic data in a finite-element model we show that the recorded displacements are best explained by a southeastward dipping (plunge angle of 9.3˚) vertically extended tri-axial ellipsoidal pressure source with semi-axis lengths of 1.9 and 2.0 km horizontally, and 5.0 km vertically.  The source is centred at 9.35 km depth below main sea level and embedded in independently imaged anomalously weak crustal rocks.  The source orientation appears to be controlled by the local stress field at the intersection of two major WNW-ESE and NW-SE striking tectonic lineaments. We derive an average volumetric strain rate of 8.4 x10-12 s-1 by transcrustal pressurisation which may have contributed to flank instability and mass wasting events in the southern and eastern sectors of the island.
Mapping catastrophic ice damage in forested area: a case study for a deciduous forest in Hungary
Authors: Zoltán László , Friedl Zoltán , Székely Balázs , Pacskó Vivien , Orbán Ildikó , Tanács Eszter , Magyar Bálint , Kristóf Dániel , Standovár Tibor
Published: March 2021

In December 2014 a catastrophic ice disturbance affected the forests of the Börzsöny Mts., Hungary. Planning salvage logging is an urgent task after such events. The use of Earth Observation (EO) data in near real-time could facilitate such planning at a critical time. However, conventional remote sensing studies apply data of passive multispectral sensors, hence the earliest post-event canopy cover damages could be examined only after foliation. Synthetic Aperture Radar (SAR) is an active remote sensing technique, which could be used for the detection of forest disturbances even outside the vegetation period. Due to its 12 days revisit time Sentinel-1 may play an important role in the fast detection of the damaged forests in the case of such events. In this work, we analyze the potential of Sentinel-1 SAR data in mapping natural disturbances in forests, through the 2014 ice break event.

We made 4 classifications with the different combination of the following variables: radar backscatter coefficients, polarimetric descriptors, interferometric coherence and optical data. We put great emphasis on the reference datasets: 3 types of field-based reference datasets were used, which include re-surveys (explicit data on changes). Based on the field data and orthophoto comparison the damaged patches were delineated manually as the most reliable reference.

We have found that none of the classifications were suitable for identifying the crown loss damages properly, but all of them were capable to detect the uproot damages. The classification using all of the variables proved to be the most reliable. The interferometric coherence with the polarimetric radar data provided the best information compared to the classification including optical data.
Clock networks and their sensibility to time-variable gravity signals
Authors: Wu Hu , Müller Jürgen
Published: March 2021

High-performance clock networks are considered as a novel tool in geodesy. Today the latest generation of optical clocks approaches a fractional frequency uncertainty of 1.0x10-18, which corresponds to about 1.0 cm in height or 0.1 m2/s2 in geopotential. The connected clocks are thus promising to enable “relativistic geodesy” in practice: Gravity potential (or height) differences can be inferred through the ultra-precise comparison of clocks’ frequencies.

In this study, we will investigate the possibility of high-performance clock networks for detecting time-variable gravity signals. In the past two decades, the satellite gravity mission GRACE, now continued by its follow-on mission, has significantly improved our knowledge on the Earth’s gravity field, especially on its changes over time. However, the results are limited in terms of spatial resolution (about a few hundreds of kilometers) and temporal resolution (standard is one month). Terrestrial clock networks can be used to observe point-wise gravity potential values at locations of interest. By continuously tracking of changes w.r.t. a reference clock, time-series of gravity potential values are obtained, which reveal the gravity variations at these locations. To elaborate this idea, we will address the following research questions:

Are clock measurements with the accuracy of 10-18 sensitive enough to time-variable gravity signals? Or what is the requirement on the clock’s performance for detecting time-variable gravity signals?

Which kinds of time-variable signals can be “seen” by clocks, the long-term trends (yearly), seasonal variations or short-term changes (weekly/daily)?

In which regions might clock networks be sensitive to time-variable gravity signals, in Amazon, Greenland or also in Europe?

An “absolute” reference clock is required for a network that should be least affected by gravity variations. Where should it be placed?

We gratefully acknowledge the financial support by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany’s Excellence Strategy EXC-2123 “QuantumFrontiers” (Project-ID: 390837967). This work is also funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) – Project-ID 434617780 – SFB 1464.
Molecular dynamics study of confined water in the periclase-brucite system under conditions of reaction-induced fracturing
Authors: Guren Marthe Grønlie , Sveinsson Henrik Andersen , Hafreager Anders , Jamtveit Bjørn , Malthe-Sørenssen Anders , Renard François
Published: March 2021

Reaction-induced fracturing may occur when dry rocks are exposed to water and undergo mineral transformations that involve a volume change. The volume increase associated with hydration reactions in rocks, like the hydration of periclase to brucite, requires a stable water film to be present at reactive grain boundaries. Recent experiments on the hydration of periclase observed that the replacement reaction slows down dramatically when the effective mean stress exceeds 30 MPa. We hypothesise that a stable fluid film is required for the brucite-forming reaction to progress, and when the applied pressure overcome the hydration force, the fluid film will collapse and be squeezed out of the grain contacts which will prevent formation of brucite. To quantify this effect, we run molecular dynamics simulations where our setup consists of two interfaces of either periclase or brucite surrounded by water, and we study the behaviour of the water film confined between two surfaces subject to compressive stress. The simulations are carried out using the ClayFF force field and the single point charge (SPC) water model in the molecular dynamics simulation program LAMMPS. Our simulations show that when the pressure reaches a few tens of MPa, the water film collapses. The process reduces the water film thickness to one or two water layers and reduces the self-diffusion coefficient of the water molecules by a factor of eight. When the water film thickness is less than two water layers, the water film thickness is smaller than the hydration shell around Mg2+-ions, which will limit the ion-transportation. The observed collapse of the water film to a single layer at a normal pressure of 25-30 MPa might explain the observed slow-down of reaction-induced fracturing in the periclase-brucite system.
Geographic information system and multi-criteria decision analysis as an assessment method for landfill site selection
Authors: Langa Chelsea , Wang Jiajie , Nakamura Kengo , Watanabe Noriaki , Takeshi Komai
Published: March 2021

Municipal solid waste (MSM) has been increasingly difficult to deal with, especially for cities of developing countries. In these cities, the increase in waste generation leads to open dumping and the development of landfills without the consideration of environmental assessment and monitoring, which may result in environmental disturbance and risk to human health. Therefore, the main goal of this study was to access the adequacy of the placement of new landfills for Maputo city, Mozambique. The study used the geographic information system (GIS) based on a multi-criteria decision approach that combined environmental, social, and technical variables to aid in the assessment of potential landfill sites. Results indicate that approximately 50% of the area is suitable for landfill placement. A further on-site evaluation is important to validate the obtained results, nonetheless, this preliminary site selection can be integrated into the MSW landfill selection to optimize waste management.
Global quantification of InSAR sensitivity for landslide deformation tracking
Authors: van Natijne Adriaan , Lindenbergh Roderik , Bogaard Thom
Published: March 2021

Landslides are lurking hazards, that often remains unnoticed. Fortunately, unstable slopes frequently show precursory deformation preceding more destructive accelerations. Thanks to satellite remote sensing, regional deformation monitoring is now available in near real-time.

Deformation time series are required for both training and validation of models for landslide nowcasting and forecasting. Various studies have shown that satellite Interferometric Synthetic Aperture Radar (InSAR) is capable of delivering the desired deformation time series. Although satellite radar data, such as from the Copernicus Sentinel-1 program, is freely available, application is not (yet) straightforward: InSAR processing is complex, computational intensive and requires specialist knowledge. Moreover, assessment of the potential of the technique on specific slopes requires experience.

Therefore, we present two concepts to a-priori assess the potential of InSAR landslide deformation tracking. First, the sensitivity index, available globally, indicates the minimum visibility of deformation in the radar signal on any slope. Second, the detection potential indicator, provided as Google Earth Engine application, performs a preliminary analysis of the Sentinel-1 data available at any specific location. Our analysis shows that on 89% of the world's slopes deformation is likely to be detectable with InSAR.

The detection potential indicator is a valuable tool in the project planning phase, while exploring the site specific possibilities for InSAR deformation monitoring. Furthermore, the sensitivity index provides overview of the slopes where large scale, machine learning driven, landslide nowcasting and forecasting are likely to succeed. We will present an analysis of the global sensitivity index, as well as demonstrate how to apply our detection potential application on a case study.
Assessing impacts of urban form on GHG emission with high-resolution spatial grids to implement nature-based solutions for carbon neutral cities
Authors: Page Jessica , Pan Haozhi , Kalantari Zahra
Published: March 2021

Globally, urban areas contribute significantly to the emissions of the greenhouse gases (GHGs) which are leading to anthropogenic climate change. To achieve long-term sustainable development goals, urban regions will need to grow and develop in such a way that they can both provide a good quality of life for all of their inhabitants, and also reduce and offset their GHG emissions to reach and maintain net-zero GHG emissions.

This work aims to further our understanding of the impact of urban form and growth on GHG emissions, to identify ways in which nature-based solutions (NBS) can be integrated into urban planning to help cities reach net zero emissions while continuing to grow sustainably. We will conduct a high-resolution (1x1km) spatial accounting and mapping of GHG emissions from selected urban anthropogenic activities (residential, commercial, transportation) for Stockholm, Sweden which includes those factors relevant to and impacted by urban form (such as density, land use pattern transportation networks, green spaces) to allow for the analysis of different types of city spatial patterns and planning decisions and their implications in GHG emissions. The results will be further expanded to cities across the European Union (EU) for comparison. Conclusions will be drawn about where and how NBS interventions should be used most effectively to reduce urban GHG emissions and facilitate sustainable city growth in the future.

Keywords: Sustainable cities; Land-use; Greenhouse Gas Emissions; Nature-based Solutions
Modeling the Sun – Earth propagation of solar disturbances for the H2020 SafeSpace project
Authors: Lavraud Benoit , Pinto Rui , Kieokaew Rungployphan , Samara Evangelia , Poedts Stefaan , Génot Vincent , Rouillard Alexis , Brunet Antoine , Bourdarie Sebastien , Grison Benjamin , Soucek Jan , Daglis Yannis
Published: March 2021

We present the solar wind forecast pipeline that is being implemented as part of the H2020 SafeSpace project. The Goal of this project is to use several tools in a modular fashion to address the physics of Sun – interplanetary space – Earth’s magnetosphere. This presentation focuses on the part of the pipeline that is dedicated to the forecasting – from solar measurements – of the solar wind properties at the Lagrangian L1 point. The modeling pipeline puts together different mature research models: determination of the background coronal magnetic field, computation of solar wind acceleration profiles (1 to 90 solar radii), propagation across the heliosphere (for regular solar wind, CIRs and CMEs), and comparison to spacecraft measurements. Different magnetogram sources (WSO, SOLIS, GONG, ADAPT) can be combined, as well as coronal field reconstruction methods (PFSS, NLFFF), wind (MULTI-VP) and heliospheric propagation models (CDPP 1D MHD, EUHFORIA). We aim at providing a web-based service that continuously supplies a full set of bulk physical parameters of the solar wind at 1 AU several days in advance, at a time cadence compatible with space weather applications. This work has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 870437.
Greenhouse gas metrics for net zero targets in science and policy
Authors: Nauels Alexander , Schleussner Carl-Friedrich , Rogelj Joeri
Published: March 2021

The treatment of non-CO2 greenhouse gases is central for scientific assessments of effective climate change mitigation and climate policy. Radiative forcing of a unit of emitted short-lived gases decays quickly; on the order of a decade for methane, as opposed to centuries for CO2. Metric selection for comparing the climate effect of these emissions with CO2 thereby comes with choices regarding short- vs. long-term priorities to achieve mitigation. The global nature of the well-mixed atmosphere also has implications for the transferability of concepts such as global warming potentials from the global to the national scale.

Here we present the implications of metric choice on global emissions balance and net zero, with a particular emphasis on the consistency with the wider context of the Paris Agreement, both on the global as well as the national level. Stylized scenarios show that interpreting the Paris Agreement emissions goals with metrics different from the IPCC AR5 can lead to inconsistencies with the Agreement’s temperature goal. Furthermore, we illustrate that introducing metrics that depend on historical emissions in a national context raises profound questions of equity and fairness, thereby questioning the applicability of non-constant global warming potentials at any but the global level. We provide suggestions to adequately approach these issues in the context of the Paris Agreement and national policy making.
From hazardous asbestos containing wastes (ACW) to new secondary raw material through a new sustainable inertization process: a multimethodological mineralogical study
Authors: Marian Narcisa Mihaela , Giorgetti Giovanna , Magrini Claudia , Capitani Giancarlo , Galimberti Lucia , Cavallo Alessandro , Salvini Riccardo , Claudio Vanneschi , Viti Cecilia
Published: March 2021

 Nowadays, asbestos-containing wastes (ACW) still represent an important environmental problem and a severe health hazard due to the well know pulmonary diseases derived from asbestos fibres inhalation. Except for a very few cases, ACW are currently confined in controlled landfills, giving rise to increasingly high amounts of still hazardous wastes. A promising alternative to landfill confinement is represented by ACW inertization, but the high cost of the inertization processes so far proposed by the scientific community have hampered the creation of actually operative plants. In this paper, we explore the possibility to use an innovative process that ensures the obtainment of asbestos-free inert material in an exceptionally short processing time, thus greatly reducing cost-related problems. The efficacy of the inertization process has been verified through accurate mineralogical investigations on both chrysotile and crocidolite de-activated fibres, through X-ray diffraction, scanning and transmission electron microscopy. Overall mineralogical, microstructural and granulometric characteristics of the inert bulk material suggest that it could be successfully re-used as a secondary raw material in ceramic industries. This innovative inertization procedure could therefore provide an effective and economically sustainable solution for ACW management.
Assessment of wind damage risk in forest areas: application with GIS and Fuzzy-AHP MATLAB graphical user interface tool
Authors: Tahri Meryem , Kašpar Jan , Novotny Miroslav , Tahri Haytham , Maanan Mohamed
Published: March 2021

In the current situation, the forest degradation areas caused by severe wind-breaking has steadily risen. This research proposes an efficient decision support tool to reduce wind damage risk and monitor forest zones. This study provides an outcome of the role of the combination of geographical information system (GIS) and Fuzzy-AHP MATLAB graphical user interface (GUI) for forest managers and environmental consultants. The user-friendly application shows how the research work ensures forest spatial planning and monitoring on ecological and forest management purposes on a regional and national worldwide scale. A representative Czech case study was chosen regarding different parameter characteristics to test our approach. The study also used map surfaces from field survey sampling results and compared the ground truth values at specific locations with data from the new model. The GIS and Fuzzy-AHP GUI are helpful for various consultants in optimizing the decision-support process in many fields.
Improving implicit geologic models based on data configuration
Authors: von Harten Jan , Wellmann Florian , de la Varga Miguel
Published: March 2021

Implicit methods have been the basis of many developments in 3-D structural geologic modeling.  Typical input data for these types of models include surface points and orientations of geologic units, as well as the corresponding age relations (stratigraphic pile). In addition, the range of influence of input points needs to be defined, but it is difficult to infer a reasonable stationary estimate from data with highly variable configuration.

Often, this results in models that show artefacts due to data configuration including oversimplified results (underfitting) in areas where data is missing, overcomplex results (overfitting) in areas of high data density and geologically unreasonable surface shapes.

In this work we explore various methods to improve 3-D implicit geologic modeling by manipulating the data configuration using locally varying anisotropic kernels and kernel density estimation. In other words, the influence of input data in the interpolation is weighted based on directions and data density. Input parameters for these methods can either be based on the original input data configuration, inferred from additional supportive data, or be based on geologic expert knowledge. The proposed methods aim to increase model control while retaining the key advantages of implicit modeling.

Model improvements will be shown using a set of typical geologic structures and regularly occurring artefacts. We compare results to previously proposed methods that integrate anisotropies in traditional kriging applications and discuss the specific requirements for applicability in implicit structural geomodeling.
Evaluation of High-Resolution Atmospheric Transport Modelling within the framework of the CTBT with Xe-133 observations in Germany and stack emission data from medical isotope production
Authors: Kusmierczyk-Michulec Jolanta , Tipka Anne , Kalinowski Martin
Published: March 2021

For every atmospheric radionuclide sample taken by the International Monitoring System (IMS) of the Comprehensive Nuclear-Test-Ban Treaty Organisation (CTBTO), the CTBTO makes use of operational Atmospheric Transport Modelling (ATM) to assist States Signatories in localization of possible source regions of any measured substance. Currently, ATM is accomplished by using the Lagrangian particle dispersion model (LPDM) FLEXPART driven by global meteorological fields with a spatial resolution of 0.5 degrees and 1 hourly temporal resolution. Meteorological fields are provided by the European Centre for Medium-Range Weather Forecasts (ECMWF ) and the National Centers for Environmental Prediction (NCEP).  

Recent studies to increase the accuracy in the CTBTO’s localization process to be applied for specific detection events, utilizes High-Resolution Atmospheric Transport Modelling (HRATM) by using the Weather Research and Forecasting model (WRF) to generate high-resolution meteorological input data for the LPDM version Flexpart-WRF.   

This presentation uses measurements from the International Monitoring System (IMS) station DEX33 in Germany of seven episodes of elevated Xe-133 concentrations in 2014 in combination with with the stack emission data of the medical isotope production facility IRE in Fleurus, Belgium. Each episode consists of 6 to 11 subsequent 24-hour samples. Backward simulations for each sample are conducted and the sensitivity to the stack emission data are analysed. All samples determined to represent a detection of IRE releases are selected to be used for an evaluation study. 

Evaluating the CTBTO’s utilization of HRATM requires to investigate the ability to localize the source region as well as the accuracy of the match and the computational performance to accomplish these results. The evaluation of HRATM results is done by using statistical metrics established during former ATM challenges. Concerning the computational performance and to account for uncertainties, sensitivity studies with varying spatial resolutions, physical parameterization variations and different regional domain setups for WRF were accomplished. This comprises a reference comparison to the operational ATM FLEXPART model with an increased spatial resolution to 0.1 degrees.   