bluuebunny/crossref_metadata_2025 huggingface dataset:
Hydraulic Geometry of ‘Equilibrium’ Channels: From Theory to Application at the National Scale
Authors: Whitfield David , Baynes Edwin , Rice Stephen , Jeffries Richard
Published: February 2023

Interactions between sediment mobility and transport capacity are one of the key controls over the geometry and morphology of gravel bed rivers; these drivers are temporally variable, fluctuating in response to changes in channel hydrology - for example, with climate change - and sediment supply - for example, via land use change. Quasi-stable, equilibrium channels occur when transport capacity and bed mobility are in balance. In both field and experimental flume studies, various efforts have been made to predict the relationship between channel hydrology (bankfull discharge, Qbf) and the equilibrium dimensions (channel width and depth). Similarly, recent studies seek to quantify equilibrium state by approximating the ratio of dimensionless bankfull shear stress to dimensionless critical shear stress (τ*bf/τ*c). If robust, these theories can offer a useful approach towards identifying channels that are sensitive to present and future aggradation and/or degradation, and can therefore be valuable tools in applications such as predicting the impacts of climate change and flood risk management. Despite their widespread use in the identification and comparison of channel stability at regional scales, these quantitative methods remain uncertain when investigating the equilibrium state of individual channels, particularly when applied to semi-managed reaches.Through completing a UK-wide assessment of upland channel stability, this study aims to field-validate hydraulic geometry theories and critically evaluate their appropriateness in river management applications within a UK context. A dataset comprising 50 upland reaches of various sizes (Qbf varied from ~2 to 270 m3s-1) was collected through field survey. Observed evidence for recent aggradation and degradation was compared against hydraulic geometry theory. Where τ*bf << τ*c, channels are predicted to aggrade, typically resulting in geometries wider and shallower than expected (and vice versa for degradational regimes, where τ*bf >> τ*c). However, when compared against field observations, predictions do not always coincide with reality. Here, we identify case study exceptions, and explore process complexities (for example, sediment supply, confinement and bank reinforcement) that lead to deviation from the predicted aggradational/degradational regime. Additionally, to account for deviations from expected channel morphology, we consider temporal variations in bed structure and sediment mobility thresholds under different hydrological regimes.
Effect of hydromulches on soil temperature in open field conditions in organic farming.
Authors: González-Mora Sara , Villena Jaime , Moreno Carmen , Morales-Rodríguez Pablo A. , Campos Juan A. , Ruiz-Orejón Antonio , Peco Jesús D. , Moreno Marta M.
Published: February 2023

During the last decades, investigation is being focused for environmental reasons on the search of alternatives to herbicides and plastics of petrochemical origin to control weeds, both in herbaceous and woody crops and especially in organic farming. With this purpose, more environmentally-friendly materials are being used worldwide, including biopolymers and papers, mainly in annual herbaceous crops due to their shorter useful live. For this reason, various research groups are investigating on the manufacturing of hydromulches of different composition and characteristics as harmless mulch materials which exert properly their functions. In this framework, in the current study we evaluated the effect of three hydromulches on soil temperature in an intensive almond crop planted in the open field. The hydromulches were based on by-products derived from the agricultural sector (barley straw, rice husk, rests from mushroom production), mixed with gypsum as a binder and recycled paper paste and applied liquidly on the ground with subsequent solidification. Additionally, two unmulched treatments were considered as control (manual weeding and a no-weeding treatments). Soil temperature was measured at 5 cm depth, and the variables considered, expressed as ºC, were maximum (Tmax), minimum (Tmin) and mean temperature (Tmean), cumulative soil heat (Cheat) and soil temperature amplitude (TA). Cheat was calculated as the sum of the daily Tmean and TA as the average of (daily max – daily min soil temperature).As general results, Tmean was higher in the unmulched controls than in the hydromulches mainly for increasing Tmax, resulting Tmin practically no affected by the cover. Consequently, TA and Cheat were higher in the controls, which shows the damping effect of the hydromulches mainly for reducing the highest temperatures, which could be positive for the crops in the current global warming context.Keywords: hydromulches, soil temperature, global warming, organic farming.Acknowledgements: Project RTA2015-00047-C05-03 - INIA (Spanish Ministry of Economy and Competitiveness).
Investigations of shallow aquifer groundwater systems of a Gallo-roman anthropized site using earth tide analysis
Authors: Nkitnam Elijah Edet , Maineult Alexis , Wassermann Jérôme
Published: February 2023

The prospect for the sustainability of the Gallo-Roman archeological site located in Genainville (France), where relics and artifacts dated to the 2rd century CE have been excavated is threaten by groundwater ingression. The in-situ building heritage materials and structures comprising a two cellea temple and an amphitheater made of limestones, are submitted all days to rising and changing groundwater levels; water being the main agent or vector of damage processes (salt weathering or freeze-thaw cycles). As part of a multi-disciplinary effort to support archeological expeditions and conserve the site structures. We report the results of groundwater monitoring and hydrogeological studies as well as tidal subsurface analysis executed to quantitatively evaluate hydraulic and geo-mechanical characteristics of the subsurface sequences toward a nondestructive approach. Continuous groundwater level data recorded in three wells in the archeological site were decomposed into constituent events that impact the observed fluctuations. The groundwater levels and barometric pressure data were acquired at 60 seconds intervals to study the response of the aquifer to strain and stress prevalence at the site. Using the method of regression deconvolution, the response to barometric pressure was disentangled from the measured water levels. Theoretical Earth tides parameters were computed using the PyGtide code, based on the ETERNA PREDICT program, at intervals of 1 minute. Harmonic analysis of the raw and filtered data using the classical Fast Fourier transform (FFT), and Singular Spectral Analysis (SSA) identify M2, S2, K1 and O1 tidal constituents as the dominant amplitudes. The SSA technique has the advantage of resolving the events into individual strands compare to the spectra of the composite data produced by the FFT. Hence, an event decomposed in the data is isolated in terms of it frequency and amplitude, and visualized. The K1 and S2 harmonic constituents were present in the filtered and raw data sets with different amplitudes. The amplitude response method was used to compute the poroelastic properties of the aquifer and characterize the subsurface heterogeneity. The model identified a semi-confined aquifer as the main groundwater storage system in the site.Keyword: Heritage site, groundwater ingress, harmonic constituents, hydraulic properties
Effect of the sea surface heat flux on upper layer circulation of the East/Japan Sea
Authors: Kim Daehyuk , Shin Hong-Ryeol , Kim Cheol-Ho , Hirose Naoki , Chang Eun-Chul
Published: February 2023

The East/Japan Sea (hereafter the East Sea) is one of the semi-closed marginal seas surrounded by Korea, Russia, and Japan. The Tsushima Warm Current (TWC) that is one of the major upper layer circulations flows into the East Sea through the Korea/Tsushima Strait (KTS). This TWC mainly bifurcates into three main branches in the southern part of the East Sea: the Nearshore Branch (NB), East Korea Warm Current (EKWC), and the Offshore Branch (OB). The upper layer circulations are greatly influenced by various external forcings such as wind stress, bottom topography, volume transport flowing through the KTS, and thermal forcing. Among them, the thermal forcing impact on the upper layer circulation of the East Sea is not well known. In this study, a three-dimensional numerical ocean model (RIAMOM) of Kyushu University is employed to investigate the impact of surface heat flux on the upper layer circulation of the East Sea. Numerical results show that the branching of the TWC is simulated regardless of applying wind stress. However, the EKWC that is one of the TWC branches does not appear without surface heat flux. Most of the TWC flows along the Japanese coast in the form of the NB. Furthermore, since there is no thermal interaction with the atmosphere, the heat supplied through the KTS tends to accumulate in the upper layer, thereby forming a thick upper layer in the overall East Sea. As the upper layer thickness increases, the TWC is significantly influenced by bottom topography. Therefore, most of the TWC flows along the developed continental shelf off the Japanese coast. In contrast, without the continental shelf, the TWC flows only along the Korean coast as a western boundary current regardless of surface heat flux. This result suggests that the surface heat flux can play an important role in controlling the bottom topographic and planetary beta effects on the upper layer circulation in the branching of the TWC. Keywords: Tsushima Warm Current, East Korea Warm Current, Surface heat flux, bottom topographic effect, planetary beta effectAcknowledgment: This work was funded by the Korea Meteorological Administration Research and Development Program under Grant KMI2022-01210.
Modelling the onset of earthquake-induced landslides as triggered slip under rate-and-state friction law
Authors: Lestrelin Hugo , Ampuero Jean-Paul , Mercerat Diego , Courboulex Françoise
Published: February 2023

While the triggering process of landslides remains are multiple, the importance of seismic waves is well established. The leading approach to study coseismic landslides is through statistical studies or simple models such as the Newmark method. While providing useful information, these approaches fall short at predicting landslide triggering especially in complex environments such as submarine conditions. Here we study the possibility to establish a simple physically-based model to fulfill this purpose. Assuming strain is localized in a thin weak layer at the base of the landslide, we model the landslide as slip on a planar sloping surface. By analogy to tectonic faults, we adopt the rate-and-state friction law on this surface, a phenomenological law widely used to describe slow sliding on faults during earthquakes. This approach produces a range of landslide behaviors ranging from stable and unstable conditions. With a one-dimensional mathematical and numerical model, representing a wave incidence normal to the landslide interface, we identify the main triggering factors of slow and fast sliding and characterize the non-linear evolution of the slip instability. In particular, we map the range of slip behaviors as a function of non-dimensional numbers, such as the ratio of incident wave frequency to seismic resonance frequency of the layer. The incident wave amplitude also play an important role in the model: the slip velocity during acceleration depends exponentially on the ratio of the incident stress wave amplitude to the ambient confining stress. This basic model is a starting point that can be extended to include other relevant processes like the coupling between pore pressure and slip.
Groundwater vulnerability assessment in areas with diverse Quaternary deposits
Authors: Männik Magdaleena , Karro Enn , Marandi Andres , Rosentau Alar
Published: February 2023

Groundwater is the most crucial drinking water resource in many areas of the world. In spite of its overall abundance, the resource remains vulnerable to pollution, as groundwater quality may be severely affected by urbanization and growth in industrial activities and agriculture. The most sustainable approach to managing groundwater quality is to ensure its protection, thus avoiding contamination. Therefore, accurate groundwater vulnerability assessment methods are necessary tools for groundwater management and protection.The DRASTIC method is one of the most widely used groundwater vulnerability assessment methods. However, in areas where the main useful aquifers are covered with an extra layer of diverse Quaternary sediments, the original DRASTIC method overestimates the vulnerability of groundwater in overflow areas and in regions where groundwater is occasionally confined. Therefore, the DRASTIC method needs to be modified to increase the accuracy of vulnerability maps in areas with a highly variable Quaternary layer, which remarkably influences the nature of the infiltration conditions.For this, in this study, the depth to water, soil properties, and impact of the vadose zone parameters of the DRASTIC methodology were modified to be suitable in areas with glacial sediments. Originally, the depth to water parameter (D) allows assessing the distance from the ground surface to the aquifer: the deeper the water table, the lower the contamination risk. In the modified DRASTIC method, the water table is as an alternative compared to the bedrock surface beneath the Quaternary sediments layer. When the piezometric head is above the bedrock surface, the aquifer acts as confined, and the movement of the pollutant to the aquifer is hindered. Therefore, the groundwater vulnerability considering the D-parameter is lower in areas where the piezometric head is above the bedrock surface and higher in areas where it is below the bedrock surface.Both the original and the modified DRASTIC methodology were applied in an area with glacial sediments located in Central Estonia. The modified DRASTIC method showed significantly better results than the original DRASTIC method. Furthermore, comparing the maps generated using the modified DRASTIC with a former local groundwater vulnerability assessment method showed considerably more similarities than this by the original DRASTIC method. Thus, the modified DRASTIC method is successfully applicable in areas with an extra layer of diverse Quaternary sediments.The study has been funded by Iceland, Liechtenstein and Norway through the EEA and Norway Grants Fund for Regional Cooperation project No.2018-1-0137 “EU-WATERRES: EU-integrated management system of cross-border groundwater resources and anthropogenic hazards
Development of Rainfall Runoff model using MIKE NAM for the flood prone basin of India
Authors: Panchal Ayushi , Yadav Sanjaykumar
Published: February 2023

Rainfall-runoff modelling is significantly carried out in order to evaluate the response of different combinations of hydrometeorological and physical characteristics of the basin. The hydrological models are developed for simulating the rainfall-runoff process. The hydrologic models are the conceptual, physical, experimental as well as artificial intelligence models. MIKE NAM model gives the conceptual rainfall-runoff model with the inputs such as rainfall, evaporation as well as the observed discharge. Various basin parameters such as interflow contribution, part of precipitation which contributes the runoff, overland flow, lower bound and upper bound limits of inflow and outflow hydrographs, interflow, baseflow, constant for time to route the base flow along with the thresholds for recharge and overland flow are being considered in MIKE NAM model. The provision to consider the parameters such as field capacity as well as wilting point is given in the NAM model. In the present study rainfall-runoff simulation has been carried out to evaluate the performance of MIKE NAM conceptual model. A sub-basin of Indian peninsular river Tapi has been chosen for carrying out the simulation. The daily data of rainfall, evaporation and river discharge for the period of 10 years has been given to the model in order to simulate the runoff. The model has been calibrated and validated by the observed data. The reliability of the developed model has been evaluated based on the statistical performance measures such as coefficient of correlation, root mean square error, Mean Absolute Error along with Nash Sutcliff Efficiency (NSE). Based on the performance of statistical parameters it can be concluded that MIKE 11 NAM model can be used effectively to simulate the runoff. The good agreement has been shown between simulated and observed river discharge and is proven to be enough accurate to predict the discharge. The threshold value of rainfall which results in to basin flooding has been computed from the present analysis for key rain gauges of the basin. The developed model can be used for forecasting future basin floods.
Towards an integrated assessment of future flooding in dynamic and data-scarce urban environments by linking Urban Structure Types with Bayesian Network modelling
Authors: Zwirglmaier Veronika , Garschagen Matthias
Published: February 2023

Limited knowledge on current and future processes as well as data scarcity pose a major challenge when it comes to the evaluation of adaptation strategies towards flooding. Current simulation approaches often lack the flexibility do deal with the inherit dynamics of future development (land use, urban growth, re-development of slum areas, infrastructure construction, etc.) in coastal cities and the resulting changes in flood hazard, exposure and vulnerability whilst facing a lack of sufficient data. Therefore, we developed a modelling approach which is able to integrate future dynamics in the three risk components, hazard, exposure and vulnerability under the uncertainties arising from lacking data as well as limited knowledge. We used Mumbai, India as a first case study to combine Urban Structure Types with Bayesian Networks (BN) and to assess pluvial flooding. BN structures are defined by process understanding supported by existing models, literature and expert evaluations. The quantification of the BNs is done by using urban structure types as proxies for relevant parameters/nodes where data is not available, like the distribution and capacity drainage infrastructure and its condition or the degree of imperviousness of certain areas. This is justified by the assumption that the appearance and the processes in urban structure types are similar. However, the probabilistic definition of nodes in a BN allows to account for the variability within an urban structure type class. As a first step, the approach was set up for the hazard component of risk. Here first results of the simulation of pluvial flooding are shown and validated against flood hotspots reported by the government of Mumbai. The simulation approach reproduced the flooding hotspots, however it has a great sensitivity towards certain parameters, especially towards the digital elevation model and the condition of the drainage infrastructure. In a next step BNs for multi-hazard evaluation and vulnerability assessment will be developed and linked, i.e. fluvial and coastal flooding as well as social vulnerability. The integration of different risk components and the flexibility of the approach help to assess the effect of individual and combinations of soft and hard adaptation measures on future flood risk.
Integrating Water-Energy-Food-Ecosystems (WEFE) Nexus Indicators and SDGs
Authors: Papadopoulou Chrysaida-Aliki , Mellios Nikolaos
Published: February 2023

The Water-Energy-Food-Ecosystems (WEFE) nexus represents a concrete system the components of which are inextricably linked with direct and indirect interlinkages. Complexity is the main characteristic describing this complicated system of interactions that affects the effective management of available resources at both physical and policy level. Thus, sectorial approaches have been proved rather insufficient and a holistic rationale is now suggested, placing emphasis on the systemic nature of the WEFE nexus. The achievement of SDGs and relevant sub-targets is also significantly affected by the sustainable use of resources as the core dimension of SDGs reflects the urgent need for the adoption of a more sustainable and resource-efficient pattern of development. This study elaborates on WEFE nexus indicators supporting sustainability in line with the priorities having been set by SDGs. Such indicators focus on issues strongly related to the several WEFE sectors such as flood alleviation, hydropower production, exploitation of biomass, rural/agricultural development, water quality protection, securing of environmental flow, food production and land use changes under climate change conditions. Moreover, the spatial dimension is taken into consideration as, according to the literature, the successful implementation and achievement of SDGs presupposes their specialization and adaptation to local needs and characteristics (e.g. country or regional level). Land use change in time (%), GHG emissions emanating from agriculture and livestock (%), crop yields (cereals, vegetables, etc.) (%), use of pesticides/fertilizers (kg) and water available for environmental flow (%) are among the proposed indicators. It should be mentioned that such indicators correspond to more than one SDG as emphasis was placed on covering as many aspects of SDGs as possible.
Varying soil organic matter composition differences between pools in acidic and calcareous soils
Authors: Jakab Gergely , Madarász Balázs , Dévény Zoltán , Zacháry Dóra , Filep Tibor , Szalai Zoltán
Published: February 2023

Intensive inversion tillage operations triggered a considerable organic carbon release from cultivated topsoils. Decreasing tillage intensity or land use change are reported to increase the soil organic matter (SOM) content of the degraded topsoil even within a decade. However, the chemical composition, storage mechanisms, and fate of the SOM surplus are not fully understood. Among the environmental and soil conditions, the role of carbonates is considered essential. The present study compares the SOM surpluses due to tillage intensity drop under acidic forest soils and Chernozems. The topsoils (0-10cm) of three long-term (~20 years) field trials were investigated in Hungary. SOM composition was estimated using Fourier transform infrared spectroscopy. Tillage intensity drop and pasture construction significantly increased the SOM content in all sites’ topsoils. At two locations, both organic matter pools increased, whereas only the mobile SOM pool has grown due to pasture construction. This suggests that a considerable amount of additional carbon can be stored in the soil, even in crop fields, using conservation technics. The SOM surplus did not change the original SOM composition trends of the labile and stable OM pools; consequently, the OM composition of the pools is rather the functions of soil and environmental conditions than sequestration mechanisms. In the acidic soil and the Chernozem under pasture, the mineral phase associated OM (stable pool) was ruled by aliphatic components, whereas the mobile, aggregation occluded OM was more aromatic. In agreement with the mainstream literature, we found the opposite trend on the other Chernozem site. Therefore the role of carbonates solely does not explain the differences. For more general trends, additional case studies must be involved. This research was funded by the National Research, Development, and Innovation Office (NKFIH), grant number: K-123953, and supported by the Eötvös Loránd Research Network SA41/2021, and EJP Sic-Soc-Dyn.
Compound precipitation and wind extremes under recent and future climate conditions
Authors: Grieger Jens , Ulbrich Uwe
Published: February 2023

Severe winter wind storms are related with strong impacts. We could show in recent studies that the co-occurrence of extreme wind and precipitation is leading to higher damages of residential buildings in comparison to non-compound events. This was done using ERA5 reanalysis data for the European winter season and daily insurance records of damages for residential buildings over Germany provided by the German Insurance Association (GDV).This study investigates the representation of co-occurrence of extreme wind and precipitation for climate simulations of the Coordinated Regional Climate Downscaling Experiment (CORDEX) for Europe (EURO-CORDEX). We use multi-model ensemble simulations with horizontal resolution of 0.44° and 0.11°. Individual simulations are analysed with respect to the characteristic of compound events for historical projections. Climate change signals for future scenarios are discussed.
Hysteresis of fire-prone weather to CO2 forcing
Authors: Kim Jin-Soo , Kim Hyo-Jeong , An Soon-Il
Published: February 2023

CO2 emission from biomass burning (BB) is one of the essential elements of the global carbon budget, with its annual mean of about 2.0 PgC/year equivalent to 15 % of 2020 fossil fuel emissions. However, while a global increase in fire-prone weather is projected alongside climate change, a quantitative understanding of how much carbon will further be released due to increased fires is highly limited, which could result in large uncertainty in meeting the net zero target. Thus, in this study, we evaluate future changes in fire-prone weather based on the fire weather index (FWI) and estimate the potential fire-induced emissions on a global scale that could be induced by climate change. To this end, 28 ensembles of idealized CO2 reduction simulations with the CESM climate model were analyzed. The results show that when CO2 in the atmosphere is doubled (2xCO2) from 367 ppm by 1 % per year, the additional emission due to increased fire weather could reach about 1.7 PgC/year, which corresponds to 82% of the current BB emission. Moreover, even if the atmospheric CO2 concentration further peaks and is reduced back to 2xCO2, the lagged response of the climate system can cause fire-prone weather and its resulting C emissions to remain higher than its previous state in many countries. These results highlight that more focus is required on the climate-fire-carbon feedback not only for more accurate future predictions but also for achieving net zero emissions in each country through a proper wildfire management strategy.
ShakeMapTM v4 study, analysis of rapid shaking assessment, optimization and evaluation of high-resolution prospects for mainland France and French overseas territories
Authors: Pellorce Léna , Mendel Véronique , Schlupp Antoine , Grunberg Marc
Published: February 2023

Shakemaps are important tools for characterizing and visualizing the geographic impact of seismic events. It is also a great support of communication and crisis management, especially in the early stage following an event. It is thus important to constrain at best the parameters controlling the calculation to have the most reliable shakemaps possible. Our study consists in optimizing the shakemaps in an application for moderate seismic activity in mainland France and French overseas territories. We studied the evolution from v3.5 to v4 of USGS ShakeMapTM and compared the associated shakemaps for past events. An in-depth study of the core calculations of the v4 was necessary to take advantage of their new approaches and optimize the parameters and configuration for the French territories. Our goal was not only to implement the ShakeMap v4 as the new automatic functional version on www.franceseisme.fr, the BCSF-Rénass website (Résif-Epos), but also to evaluate the prospects and limitations for computing high-resolution shakemaps. We analyzed the uncertainties of shakemaps between rapid shaking assessment based on preliminary data and the late reference shakemap based on complete validated datasets for recent damaging or largely felt events in France.What can we improve today to reach high-resolution? What might be possible in a few years? Finally, what are the limits that we may never be able to overcome in the ShakeMapTM  program approach?
Holistic approach in the forensic analysis of geological trace evidence: as Forensic Botanists and Geologists may help judicial investigations
Authors: Mondello Fabio , Morabito Marina , Somma Roberta
Published: February 2023

In the 1978, Gianni Lombardi and Valerio Giacomini, two Italian experts in forensic geology and botany, respectively, were involved by the judicial authority for analysing the sands and plant remains found in the clothing and moccasins of the honorable Aldo Moro, kidnapped and killed by terrorists. Experts had to determine the site where this material transfer occurred.As demonstrated by the analyses carried out by these experts, plant taxonomists can give useful information in forensic analyses especially for events occurring outdoor. Small plant traces spread in quantity, like pollens, spores, thorns, seeds and small fruits, may easily transfer to the clothing and footwear of people or to the same human body, moving outdoor in the countryside.In 2020, 42 years later, the authors of this research were involved by the judicial systems to reconstruct the events related to the disappearance of two persons, in the Sicilian countryside, found cadavers a few days after in a site near the last sighting of them.The research focused on the morphological description of thorns, other pointed structures, and seeds produced by plants thriving in the scene of events. For simplicity, it was chosen to use the generic term "thorns" to indicate pointed plant structures, although aware that the term "prickle" should have been used for epidermal structures, “thorns” strictly for stem-derived structures, and "spines" for other structures derived from leaves, petioles or stipules.A photographic atlas of thorns and seeds was produced with the species found in the scene of the events. A comprehensive description of plants as they appeared in situ as well as of their thorny appendices was made, and explanatory pictures were captured, both in situ and under the stereoscopic microscope in the laboratory. The extensive biometric analysis made on thorns and seeds of all collected species in the scene of events was recorded.Soil traces and microtraces of forensic samples of unknown origin (from the victims’ bodies and their belongings) were investigated for the presence of thorns or thorn fragments and seeds, which were then compared with those recorded in the atlas.The organic component (vegetal elements) of the forensic geological traces from victims and their belongings was predominant in quantity over the inorganic one.Comparative observations allowed to identify hundreds of thorns and thorn fragments and several hundreds of seeds found on the clothes and footwear of both victims, as plants thriving in the area under investigations. Basing on the punctual distribution of individual plants, the analysis of thorn traces and seeds was useful, together with geological analyses on sands and clay minerals, in reconstructing the path of the victims in the hours immediately preceding their death and, therefore, provided valuable information to the investigating authorities.
IPFS Pinning Service for Open Climate Research Data
Authors: Kulüke Marco , Kindermann Stephan , Kölling Tobias
Published: February 2023

The InterPlanetary File System (IPFS) is a novel decentralized file storage network that allows users to store and share files in a distributed manner, which can make it more resilient if individual infrastructure components fail. It also allows for faster access to content as users can get files directly from other users instead of having to go through a central server. However, one of the challenges of using IPFS is ensuring that the files remain available over time. This is where an IPFS pinning service offers a solution. An IPFS pinning service is a type of service that allows users to store and maintain the availability of their files on the IPFS network. The goal of an IPFS pinning service is to provide a reliable and trusted way for users to ensure that their files remain accessible on the IPFS network. This is accomplished by maintaining a copy of the file on the service's own storage infrastructure, which is then pinned to the IPFS network. This allows users to access the file even if the original source becomes unavailable.We explored the use of the IPFS for scientific data with a focus on climate data. We set up an IPFS node running on a cloud instance at the German Climate Computing Center where selected scientists can pin their data and make them accessible to the public via the IPFS infrastructure. IPFS is a good choice for climate data, because the open network architecture strengthens open science efforts and enables FAIR data processing workflows. Data within the IPFS is freely accessible to scientists regardless of their location and offers fast access rates to large files. In addition, data within the IPFS is immutable, which ensures that the content of a content identifier does not change over time. Due to the recent development of the IPFS, the project outcomes are novel data science developments for the earth system science and are potentially relevant building blocks to be included in the earth system science community.
Stakeholders’ Perception on Mangrove Ecosystem Services and Marine Plastic Waste Management in Cebu Islands, Philippines
Authors: Jones Gaynor , Taboada Evelyn , Paler Maria Kristina , Balanay Pearl , Tagalog Shaira , Orate Jeanie
Published: February 2023

Marine plastic litter has become a serious global concern, which continuously plagues vulnerable countries and communities.  The Philippines has found itself as one of the top plastic polluters in the marine environment.  Its plastic waste problem has been documented in several studies; however, its implications are still unclear though a call for serious action is certain.  The existence of waste management practices adapted from a legal basis such as The Ecological Solid Waste Management Act of 2000 (known as the Republic Act No. 9003 or RA 9003) has greatly contributed to its call for action.  However, data from studies conducted to date suggests that the plastic waste problem is far from being addressed and is potentially starting to affect other environmental ecosystems such as mangrove ecosystems.  This study aims to assess the perception of the stakeholders on what ecosystem services the mangroves can offer and how this can benefit them.  Similarly, this seeks to examine what the community needs in order to mitigate improper plastic waste disposal especially in mangrove ecosystems.  A series of focus group discussions (FGDs) was conducted in 4 municipalities and 3 cities around the province of Cebu, Philippines. A total of 142 participants and representatives from the Academic, Business, Community, and Government (ABCG) sectors joined the activity. (ABCG model).  The results show that the people of Cebu province are more cognisant of the provisioning and regulating ecosystem services of mangroves than its support and cultural services.  One notable misconception among them is their view of mangroves as a filtering area where plastic wastes get trapped before going to the sea. Analysis on the behavioural factors influencing the people of Cebu province in the context of plastic waste management practices also show that Self-regulation>Risk influences them to manage their waste but Ability>Attitude>Norm has more weight in hindering them from practicing proper waste management.  This suggests a need for capability and capacity building interventions integrated in sound policy implementation that would encourage and empower the people to practice good plastic waste management on a more serious and consistent level especially in marine ecosystems. This study champions the ABCG model in this regard.
Moving away from deterministic solutions: A probabilistic machine learning approach to account for geological model uncertainty in groundwater modelling
Authors: Busk Dahl Mathias , Norvin Vilhelmsen Troels , Bødker Madsen Rasmus , Mejer Hansen Thomas
Published: February 2023

Decision-making related to groundwater management often relies on results from a deterministic groundwater model representing one ‘optimal’ solution. However, such a single deterministic model lacks representation of subsurface uncertainties. The simplicity of such a model is appealing, as typically only one is needed, but comes with the risk of overlooking critical scenarios and possible adverse environmental effects. Instead, we argue, that groundwater management should be based on a probabilistic model that incorporates the uncertainty of the subsurface structures to the extent that it is known. If such a probabilistic model exists, it is, in principle, simple to propagate the uncertainties of the model parameter using multiple numerical simulations, to allow a quantitative and probabilistic base for decision-makers. However, in practice, such an approach can become computationally intractable. Thus, there is a need for quantifying and propagating the uncertainty numerical simulations and presenting outcomes without losing the speed of the deterministic approach.This presentation provides a probabilistic approach to the specific groundwater modelling task of determining well recharge areas that accounts for the geological uncertainty associated with the model using a deep neural network. The results of such a task are often part of an investigation for new abstraction well locations and should, therefore, present all possible outcomes to give informative decision support. We advocate for the use of a probabilistic approach over a deterministic one by comparing results and presenting examples, where probabilistic solutions are essential for proper decision support. To overcome the significant increase in computation time, we argue that this problem can be solved using a probabilistic neural network trained on examples of model outputs. We present a way of training such a network and show how it performs in terms of speed and accuracy. Ultimately, this presentation aims to contribute with a method for incorporating model uncertainty in groundwater modelling without compromising the speed of the deterministic models.
Landslide expression in C-band SAR backscatter change images: a physically- and empirically-based conceptual model
Authors: Lindsay Erin , Devoli Graziella , Reiche Johannes , Nordal Steinar , Frauenfelder Regula
Published: February 2023

Using synthetic aperture radar (SAR) backscatter imagery can enable faster detection of landslides compared to optical images, particularly where there is persistent cloud cover or shadows. However, SAR images are underutilised for this purpose. This is partly due to the more complicated pre-processing requirements, and also due to the less intuitive interpretation of landslide signatures in SAR, relative to optical images. The problem of landslide identification in SAR backscatter imagery is complex. Landslides can occur in almost any land cover type and their expression in the environment can vary significantly depending on the material type and failure mechanisms. How this affects the expression of landslides in SAR backscatter data has so far not been well understood. In this study, we attempt to reduce this knowledge gap by investigating the physical basis for the expression of landslides in SAR backscatter data.This involved identifying trends in the spatial and temporal signatures of landslides in 30 case studies around the world, representing diverse physiographical and landslide types. Morphometric features of landslides (scarp, transport and deposition zone) were mapped separately, and quantitative analysis of their pixel values in multi-temporal Sentinel-1 SAR backscatter images was performed. The role of environmental factors including the orientation of the landslide with respect to the sensor (local incidence angle), land cover, seasonal variations, and water content were also analysed.The terrain influenced whether or not landslides were detectable, while the presence or absence of woody vegetation determined if there would be an increase or decrease in backscatter intensity. Landslides in non-forested areas that produce an increase in surface roughness, are best observed using VV polarisation and show increased backscatter intensity. Deposit zones also tend to show increased backscatter intensity, unless very fine material was deposited as a smooth flat surface (e.g. from non-turbulent mudflows). Removal of the forest is best viewed in VH polarisation, and produces a recognisable pattern of both decreased (due to radar shadow, and change from volumetric to surface scattering) and increased (due to direct and double bounce reflection from vertical tree trunks and scarp surface) backscatter intensity. Landslides that occur in mixed vegetation types, and those that do not significantly change the scattering properties of the ground surface, did not produce a detectable change in the C-band SAR images.  The findings were summarised in a conceptual model, based on SAR theory and empirical evidence. This can be used to help interpret landslides in SAR backscatter change images, and to design representative or synthetic datasets for training automatic landslide detection models. 
The coupled evolution of forearc and back-arc basins: inferences from 2D and 3D numerical modelling
Authors: Balazs Attila , Gomes Ana , Faccenna Claudio , Gerya Taras
Published: February 2023

The subsidence history of forearc and back-arc basins reflects the relationship between subduction kinematics, mantle dynamics, magmatism, crustal tectonics, and surface processes. The distinct contributions of these processes to the topographic variations of active margins during subduction initiation, oceanic subduction, and collision are less understood.We conducted a series of 2D and 3D thermo-mechanical numerical models with the codes 2DELVIS and 3DELVIS, based on staggered finite differences and marker-in-cell techniques to solve the mass, momentum and energy conservation equations. Physical properties are transported by Lagrangian markers that move with the velocity field interpolated from the fix Eulerian grid. We discuss the influence of different subduction obliquity angles, the role of mantle flow variations and their connection with sediment transport and upper plate deformation. Furthermore, slab tearing and the gradual propagation of slab break-off is modelled during collision.The models show the evolution of wedge-top and retro-forearc basins on the continental overriding plate, separated by a forearc high. They are affected by repeated compression and extension phases. Compression-induced subsidence is recorded in the syncline structure of the retro-forearc basin from the onset of subduction. The 2–4 km upper plate negative residual topography is produced by the gradually steepening slab, which drags down the upper plate. Trench retreat leads to slab unbending and decreasing slab dip angle that leads to upper plate trench-ward tilting. Back-arc basins are either formed along inherited weak zones at a large distance from the arc or are connected to the volcanic arc evolution leading to arc splitting. Backarc subsidence is primarily governed by crustal thinning that is controlled by slab roll-back and supported by the underlying mantle convection. High subduction and mantle convection velocities result in large wavelength negative dynamic topography. Collision and continental subduction are linked to the uplift of the forearc basins; however, the back-arc records ongoing extension during a soft collision. During the hard collision, both the forearc and back-arc basins are ultimately affected by the compression. Our modeling results are compared with the evolution of Mediterranean subduction zones.
Deep Learning-aided Temporal Downscaling of Satellite GravimetryTerrestrial Water Storage Anomalies Across the Contiguous United States (CONUS)
Authors: Uz Metehan , Akyılmaz Orhan , Shum Ck
Published: February 2023

Gravity Recovery and Climate Experiment (GRACE) and GRACE-FollowOn (GFO) satellites can monitor the global spatio-temporal changes in terrestrial water storage anomalies (TWSA) with monthly temporal and ~300 km spatial resolutions. Since these native resolutions may not be adequate for various studies requiring better localization of TWSA signal both in spatial and temporal domains, in recent years, considerable efforts have been devoted to downscaling TWSA to higher resolutions. However, the majority of these studies have focused on spatial downscaling; only a few studies attempted to improve the temporal resolution. Here, we utilized an in-house developed Deep Learning (DL) based model to downscale the monthly GRACE/GFO Mass Concentration (Mascon) TWSA to daily resolution across the Contiguous United States (CONUS). The simulative performance of the DL algorithm is tested by comparing the simulations to independent (non-GRACE) dataset and the land hydrology models. In addition, we assessed the potential of our daily simulations to detect long- and short-term variations in TWSA. The validation results show that our DL-aided simulations do not overestimate or underestimate GRACE/GFO TWSA and can monitor variations in the water cycle at a higher temporal resolution.
Freezing-induced bromate reduction through iodide and its implications
Authors: Nguyen Quoc Anh , Kim Kitae
Published: February 2023

Freezing, which is the naturally facile process in the cold climate regions, has been extensively investigated as a non-contamination and effective cost method in the environmental treatment. The reactive halogens chemistry has a huge impact on the global environment, especially polar regions. Here, we elucidated the generation of iodine (I2), tri-iodide (I3-), and bromide (Br-) through the bromate (BrO3-) reduction by iodide (I-) in the unfrozen solution of ice while it did not take place in aqueous solution. This appreciably enhanced transformation was attributed majorly to the freeze concentration effect of BrO3-, I-, and protons (H+) in the liquid boundary of ice. The ice grain boundary regions created as well as the consumption of BrO3- in the BrO3-/I-/freezing systemin those regions during freezing were visualized with the confocal Raman microscope. pH decrease (the accumulation of H+) during freezing was measured quantitatively by the UV-Vis absorption spectra of cresol red (as the acid-base indicator). Also, the freeze concentration effect of I- on the BrO3- transformation was verified in the differently experimental conditions of pH and/ or I- concentration. The study on the acceleration of BrO3-/I-/freezing system provides not only an unknown production pathway of bromine and iodine speciation in the polar environment but also the environmentally friendly insight into BrO3- treatment (known as the disinfection byproduct during ozonation in water treatment). 