bluuebunny/crossref_metadata_2025 huggingface dataset:
Testing and Validation of Multiple Decision Trees Models for Rapid Coseismic Landslide Susceptibility Assessment
Authors: Lai Tz-Shin , Chao Wei-An , Yang Che‐Ming , Wu Yih-Min , Chang Jui-Ming
Published: February 2023

Coseismic landslides can result in significant economic loss and casualties. In Taiwan, combined effects of high seismicity, geology and steep topographic relief cause the high susceptibility of landslides associated with earthquakes. In this study, we use Newmark analysis, decision tree (DT) and multivariate decision tree (MDT) algorithm to perform the nowcasting and delivery susceptibility map on website. The strong-motion records with local magnitude larger than 6.0 from 1990 to 2020 are collected and the 175 potential planar failure slopes with similar lithology are selected as the target slopes (TS). We first found the representative station (RS) satisfied the specific thresholds of peak ground acceleration (> 196 gal) and Newmark displacement (> 10 cm), and then hillslopes around the TS associated with the RS with potential failures caused by earthquakes were carefully mapped by satellite images. The classification labels of failure and non-failure are used for the classification and regression trees (CART), C5.0 and multivariate regression trees (MRT). Overall, the accuracy (ACC) and false-negative rates (FNR) of C5.0 model for entire Taiwan were 83.3% and 10.7%, respectively. In advanced, the ACC can reach 95.8% in central Taiwan with merely 5.6% FNR. We use 2022 Hualien Yuli earthquake and 2022 Chishang earthquake to validate the DT model. The ACC is 83.3% with FNR = 0% in Hualien Yuli earthquake and the ACC is 76.9% with FNR = 0% in Chishang earthquake for entire Taiwan C5.0 model, indicates the model has reliable prediction outcomes. However, these two earthquakes didn’t cause the coseismic landslide case associate with 175 TS to validate the true positive portion. Additional TS, which are the coseismic landslide caused by 2022 earthquakes, should be added in our training data. Finally, the results in this study have been displayed on the web-based for rapid coseismic landslide susceptibility assessment providing the distribution of risk slopes with traffic lights for emergency response and disaster mitigation.
Impact of groundwater abstraction on subsurface thermal regimes
Authors: Klepikova Maria , Bense Victor , Bour Olivier , Guiheneuf Nicolas , le Borgne Tanguy
Published: February 2023

Being the world’s largest freshwater resource, groundwater is at a continuous risk of overabstraction for human water use. Beside substantial drops in groundwater levels that are the consequence of unsustainable groundwater abstraction, which modify the recharge/discharge relationships between large-scale hydrogeological units, this anthropogenic hydraulic forcing is also responsible for changes in thermal regimes within the critical zone. While the impact of global groundwater pumping on the hydrogeological cycle has long been demonstrated, we still have insufficient knowledge on the influence of human activities on groundwater temperatures and, as a consequence, on stream thermal regimes and groundwater quality.In this contribution we discuss temperature anomalies that develop in the shallow subsurface as a result of localized groundwater extraction. We study different hydrogeological settings, i.e., porous and fractured aquifers, that we explore via numerical modelling and comparison with field observations. In the field, we use repeated temperature-depth borehole profiles separated by decades, the advantage of which is that differencing the temperature logs for individual boreholes yields real temperature change and eliminates steady-state sources of curvature. Thus, it enables us to detect changes in subsurface thermal regimes, resulting from transient conditions, i.e., climate change and changes in groundwater hydrodynamics.
DRAGON J-ALPS: study of aerosol properties in Japanese Alps and valley region
Authors: Sano Itaru , Mukai Sonoyo , Makiko Nakata , Holben Brent , Maki Teruya
Published: February 2023

A field campaign, AERONET DRAGON J-ALPS (joint research on aerosol process studies), is planned to is planned to study the influence of mountain topography on aerosol transport, the aerosol life cycle, and aerosol properties in a narrow valley. DRAGON/J-ALPS was planned to start in March 2020, with 12 AERONET Cimel sun/sky radiometers deployed in the central valley surrounded by the Japanese Alps. Some instruments were also placed in the mountains to study aerosols transported through the higher layers. In April 2020, however, observations were discontinued due to the COVID-V2; they resumed in the fall of 2020 and were extended until the spring of 2021. Some sites also operated until fall 2021.The initial results of DRAGON/J-ALPS are presented in terms of aerosol characteristics from ground and satellite observations, with particular focus on regional background aerosols and long-range transboundary aerosols (biomass burning smoke, Asian dust, and volcanic smoke) across the Japanese Alps. Results of regional model simulations will also be presented.
The diurnal warm layer and its consequences for the upper ocean: from EUREC4A-OA observations and the global coupled ICON-ESM
Authors: Schuette Florian , Lange Diego , Putrasahan Dian , Carrasco Ruben , L'Herguet Pierre , Zhang Dongxiao , Speich Sabrina , von Storch Jin-Song , Karstensen Johannes
Published: February 2023

The uppermost 0-20m depth of the ocean within the mixed layer (ML) were investigated on diurnal scales using data collected during the EUREC4A campaign in the western tropical Atlantic. The results are compared against data from the global coupled Earth System model ICON. In both datasets is the diurnal impulse generator the penetrating shortwave solar radiation, heating the first meters of the ocean. During day on top of the ML a stably stratified near-surface layer, called the diurnal warm layer (DWL), can be formed. Depending on the wind conditions or the amount of incoming solar radiation the depth of such a DWL can reach from several centimeters to tens of meters. Associated to the stable stratification (and the wind) shear is produced which propagates down with time. At that point, the model and the observations start to differ. Using high-resolution current measurements of ADCP’s mounted on saildrones the detailed structure of the descending shear layer is observed. The cycle of shear instability leads the diurnal mixing cycle, typically by 2–3 h, consistent with the time needed for instabilities to grow and break (observed by microstructure measurements). In the morning, the turbulence decays and the upper ocean restratifies. At this point, wind accelerates the near-surface flow to form a new unstable shear layer, and the cycle begins again. Since the study area is located around 15°N, the excited layers are affected by the Coriolis force, which causes the descending shear layer to rotate around the inertial frequency of 1.8 days. Compared to the global coupled earth system model, these processes cannot be represented in such detail here. This leads to lower shear (and also mixing) at the different time and depth. Different model configurations show that even small differences in the upper 20m of the ocean, such as those observed, can lead to quite large changes in the model, e.g., a different strength of the ocean current system down to 1000m depth.
Increased CO2 Efflux from Retreating Salt Marshes Occurs Before Active Erosion
Authors: Stolpmann Lea , Balke Thorsten , Bass Adrian
Published: February 2023

Coastal wetlands are providing a variety of ecosystem services, among others valuable carbon stores, collectively referred to as blue carbon. The carbon sequestration potential is constrained by the difference between organic matter burial and its decomposition. Soil conditions are influencing organic matter decomposition rates and must be accounted for in blue carbon budgets. The differential soil to atmosphere CO2 efflux between salt marsh sites experiencing differing geomorphic conditions (eroding vs. prograding) was measured in this study performed in Scotland, UK. Further, potential processes responsible for soil to atmospheric CO2 flux were determined, including groundwater level, soil temperature and soil characteristics (i.e., grain size, carbon content and carbon stable isotopes). Eroding salt marsh sites had a 26.48% higher CO2 efflux than expanding sites. Generalised linear mixed effects model (GLMM) and Linear mixed effects model (LMM) showed the relationship between CO2 efflux and tidal cycle, erosion status, and the distance to the seaward vegetation edge. The efflux of CO2 from the salt marsh is influenced by the underlying geomorphological conditions. These results highlight that salt marshes should be regard as heterogenous systems, especially considering analyses of future carbon storage budgets.
A modelling framework to estimate the impact of rewetting projects on agricultural activities in Flanders
Authors: Estrella Diana , Mulder Martin , De Swaef Tom , Bartholomeus Ruud , Garré Sarah
Published: February 2023

The Flemish coalition agreement 2019-2024 places a strong emphasis on increasing our resilience to drought, including through the active use of resilient zones with (extra) nature to mitigate the effects of climate change. Neighboring agricultural activities can experience positive effects by buffering water in the landscape. However,  too shallow  groundwater levels can have consequences for the workability of the land and the crop growth itself.  This means that farmers and policy-makers do not only need to adapt to an increased occurrence of droughts, but probably also to the impacts of excessive soil water. Therefore, the project PEILIMPACT developed and applied model instruments, adapted to the Flemish conditions, to determine the impact of rising groundwater levels on the yield of common agricultural crops. The model SWAP-WOFOST, part of Water Vision Agriculture as developed for the Netherlands, was used for this purpose together with open data layers available in Flanders. The evaluation framework was based on an extensive literature review of the main points of attention in agriculture. Possible obstacles and concerns from main stakeholders (e.g. farmers) in different regions were also included in the evaluation framework. Results indicate that the impact of soil moisture conditions on crop yields is highly variable, both spatially and temporally. Areas with very shallow groundwater levels (>1 m) are negatively affected in wet years, but benefit in dry years. The opposite occurs in deeper groundwater levels, where more precipitation could compensate for the low groundwater contribution. The final report as well as the model instruments are freely available and documented so that application to specific locations where rewetting projects are planned is possible for all interested parties.  
Ranking methodology and geochemical character of different waste materials of an epithermal mineralization from the Recsk Mining Area, Hungary
Authors: Alwani Naji , Jordan Gyozo , Szabó Péter , Hitka Geza
Published: February 2023

Mining activities inevitably generate contaminants in high quantities that can pose a risk at soil, water, biota and humans. This article describes a systematic method to understand the geochemical properties of various mine waste heaps and to investigate the waste material of a flotation mud and a waste rock heap coming from a high-sulphidation epithermal mineralization of the Recsk Mining Area, Hungary, and an application of a risk evaluation technique is presented.Field sampling took place in the Recsk Mining Area on the H2 tailings heap and on the H7 waste rock heap where a total of 48 samples were collected. The geochemical properties of the waste material were assessed to shed light on the behavior of the potential toxic elements. The element concentration of the samples was determined by inductively coupled plasma mass spectrometry (ICP-MS) inductively coupled plasma optical emission spectrometry (ICP-OES) and ion chromatography. In addition, the mineral phases present were detected by X-ray diffraction (XRD). Ranking of potential toxic mining waste was calculated using two indicators: the index of contamination (IC) and the Hazard Average Quotient (HA) which was used to calculate the Toxicity Factor (TF). The mobility of each element was estimated using a simple formula followed by univariate and bivariate data analysis methods.Results show that the potentially toxic elements are present in varying concentrations in the two studied wase heaps, even though they are originating from the same mineralization. They also behave differently on the studied waste heaps in terms of mineral composition. The calculated IC values were very high, exceeding the limits, and TF values were low for mining waste according to the legislative concentration pollution limits. A unique approach is needed for each type of waste heap in order to facilitate a successful remediation or secondary raw material extraction.Keywords: mining waste; geochemistry; contamination, index of contamination, Hazard Average Quotient
Regional-scale groundwater modeling, focusing on boundary inflow and impact assessment of managed aquifer recharge in karst systems
Authors: Genzel Marcus , Reimann Thomas , Kavousi Heydari Alireza , Hartmann Andreas , Doummar Joanna , Rudolph Max-Gustav
Published: February 2023

Managed aquifer recharge (MAR) is a powerful approach to counteracting the negative impacts of overexploited groundwater resources and enhancing groundwater availability in water-scarce regions. One common MAR strategy is aquifer storage and recovery (ASR). Theoretically, the ASR techniques can be adopted for karst systems to store and recover water within the system or to increase the subsurface inflow into the alluvial system from the adjacent upland karst system. However, karst systems present a particular challenge for the application and technical implementation of ASR, due to the associated strong anisotropy and heterogeneity, high runoff dynamics, as well as the underlying uncertainties regarding the available data.This research is oriented to provide a regional scale model of a karst-alluvial system in Lebanon, analyzing the impact of MAR scenarios as well as quantifying boundary inflow to adjacent alluvial systems. For this reason, several model conceptualizations (considering multi-model concepts) and ASR application scenarios are adopted and tested. For transferability, real-world case studies and idealized yet generalizable systems are considered and assessed. The model pre- and postprocessing is entirely script-based and uses open-source tools to ensure sustainable useAn anisotropic fast-marching algorithm is used to create spatially distributed karst channel networks through the Python package pyKasso. In addition, a discrete continuum model is developed (e.g., CfPy), where the stochastic conduit networks are implemented as a large ensemble of the plausible and representative karstic system. The regional karst alluvial model results are also used to make general recommendations for MAR site selection in the karstic study site.
Differentiable Geomodeling: Opportunities and Challenges
Authors: Wellmann Florian , de la Varga Miguel , Liang Zhouji , Jian Yang
Published: February 2023

Geological models can be constructed with a variety of mathematical methods. Generally, we can describe the modeling process in a formal way as a functional relationship between input parameters (geological observations, orientations, interpolation parameters) and an output in space (lithology, stratigraphy, rock property, etc.). We evaluate here the potential of using not only the output value (prediction) itself, but also its partial derivative with respect to the input parameters to gain insight into the interpolation process, to speed-up model calibration, and to enable high-dimensional uncertainty quantification.The calculation of this partial derivative through the complex modeling procedure requires additional work – however, this step has been greatly simplified due to progress in automatic differentiation approaches in recent years. Specifically, all modern machine learning frameworks enable a calculation of the derivatives, as this is an essential component of training in deep neural networks. We can benefit from these developments for specific geological modeling functions – and if we take specific care in the numerical implementation.In this presentation, we discuss the basic principles between differentiable geomodelling methods, show implementation methods, and discuss potential difficulties and open challenges. We exemplify the advantage of the additional work through efficient implementations of sensitivity analyses and gradient-based sampling methods for uncertainty quantification in geological models.
Spatial and temporal variability of compound drought heatwave events in the Northern Hemisphere
Authors: Diao Chan , Zhao Liang , Wu Xiuchen , Li Yang
Published: February 2023

Recent decades have witnessed a notable increase in the compound drought and heatwave events (CDHW) in many regions across the globe, which may have more complex and intense implications on terrestrial ecosystem stability than individual extreme events.  It is necessary to clarify the response of terrestrial ecosystems to compound drought-heatwave events. However, the research is remain poorly understood about this. Therefore, we used the Standardized Precipitation Index (SPI) and temperature data to extract the regions where occur compound drought and heatwave events in global. The results obtained in this study are as follows: Firstly, the majority of the regions that have experienced compound drought heatwaves have experienced only one such event, while only a small percentage have experienced two such events. Secondly, we found that the number of compound drought heatwave events in all years is generally more in drylands than in wetlands.
Optimized flux estimation of a sulfonamide contaminant plume discharging to a stream using fluorescence screening
Authors: Lemaire Gregory G. , Vinther Laila , Thrane Britt B. , Harrekilde Dorte , Ottosen Cecilie B. , Hansen Josefine L. , Broholm Mette M. , Bjerg Poul L. , Dissing Lone , Pedersen Jørn K.
Published: February 2023

Sulfonamides are widely used antiobiotics and a threat to water resources and related ecosystems. While the direct discharge from untreated sewer or wastewater to surface water is a well-known pathway to the aquatic environment, only a limited number of studies have looked at the discharge and fate of sulfonamides from a contaminant plume to surface water so far.In this study, we investigated a sulfonamide contaminant plume discharging to a stream in Denmark. The sulfonamides (originating from a former production facility), are transported through a multilayered sandy aquifer and discharge to a groundwater-fed stream located down gradient. Our objectives were to evaluate if a screening using fluorescence properties could be used to delineate the sulfonamide contaminant plume and support the contaminant mass discharge estimation (both by transect method and in-stream measurements).Direct push technics in combination with a fluorescence screening allowed a relatively unexpensive coarse delineation of high concentrations areas (as opposed to laboratory analysis) down to 15 m.b.g.s. and ergo optimization of monitoring wells / screen locations in the transect. Chemical analyses were combined with slug test and hydraulic gradient estimates via continuous monitoring to quantify the sulfonamide flux and its temporal variations in a 2 km-long transect along the stream (24 monitoring wells with 3 - 6 screens).The estimated sulfonamide mass discharge (transect based) is in good agreement with the mass discharge calculated from in-stream measurements, highlighting the relevance of the screening approach to select appropriate measurement point locations. Furthermore, the comparison between the flux in both stream and groundwater compartments shows that the degradation of sulfonamides seems relatively limited in the near-stream and hyporheic zone, with the exception of the sulfanilic acid. The results of this study will be used for the prioritization of remedial actions along the main discharge zones.
GTool: A new user-driven tool aiming at achieving a sustainable groundwater governance in Mediterranean aquifers
Authors: Sánchez García Damián , Argamasilla Ruiz Manuel , Palomino Gómez Adrián , Díaz Hurtado Miguel Ángel , García Ortiz Lupicinio , Núñez Moreno Francisco , Nieto López José Manuel , Aguilera Romero David
Published: February 2023

Climate change scenarios obtained by models foresee changes in the availability of water resources that make it necessary to improve their management, especially for groundwater, as they are one of the most important, but at the same time most vulnerable, sources of fresh water on the planet. Groundwater governance can be defined as "the process by which groundwater is managed through the application of elements such as accountability, participation, availability of information, transparency, customs and policy." The manner in which this governance is carried out can have direct implications for the status of groundwater, both qualitatively and quantitatively, hence its importance when analysing the status of an aquifer or groundwater body. The objective of this contribution is to present GTool, a brand new digital and user-driven tool developed in the framework of the EU PRIMA project GOTHAM, which aims at establishing a new groundwater governance model based on a bottom-up approach. One of the modules that GTool integrates, called “Groundwater Response Module”, has been designed with the objective of forecasting the most probable groundwater body status according to a selection of variables. The input data used to assess the current and expected status of the aquifer comprises groundwater quality trends, prediction of scarcity and drought indexes, the potential use of non-conventional water resources (reused water), the increase of available resources by the implementation of managed aquifer recharge (MAR) techniques, potential groundwater quality restoration by means of remediation techniques, and current groundwater governance. This methodology has been applied in Campo de Dalías-Sierra de Gádor groundwater body (Southern Spain), which is characterised by large groundwater abstraction (mainly for the irrigation of greenhouses crops), steep and lasting drops of groundwater levels and subsequent groundwater quality degradation by seawater intrusion and salinity increase. Results show that, despite the good groundwater governance and high MAR and non-conventional water resources potential currently existing in the area, Campo de Dalías-Sierra de Gádor groundwater body is expected to have a ‘bad’ status in the medium term, principally due to the forecasted scarcity and drought indexes and, secondarily, upward trends regarding salinity (electrical conductivity, chloride) and nitrate contents.
Increasing the reliability of seismic classification: A comparison of strategies to deal with class size imbalanced datasets.
Authors: van Dinther Chantal , Malfante Marielle , Gaillard Pierre , Cano Yoann
Published: February 2023

Recent employment of large seismic arrays and distributed fibre optic sensing cables leads to an overwhelming amount of seismic data. As a consequence, the need for reliable automatic processing and analysis techniques increases. Therefore, the number of machine learning applications for detection and classification of seismic signal augments too.A challenge however, is that seismic datasets are highly class imbalanced, i.e. certain seismic classes are dominant while others are underrepresented. Unfortunately, a skewed dataset may lead to biases in the model and thus to higher uncertainties in the model predictions. In the machine learning literature, several strategies are described to mitigate this problem. In presented work we explore and compare those approaches.For our application, we use catalogues and seismic continuous recordings of the RD network in France [RESIF, 2018]. Using a simple 3-layered convolutional neural network (CNN) we aim to differentiate between six seismic classes, which are based on hand-picked catalogues. The training set we obtained is highly skewed with earthquakes as the majority class, containing 77% of the samples.  The remaining classes (quarry blasts, marine explosions, suspected induced events, noise and earthquakes with unquantifiable magnitude) represent 2.1 - 7.5% of the dataset.We compare four strategies to deal with an imbalanced datasets for a multi-class classification problem. The first strategy is to resample the dataset (i.e. reduction of the majority class). Another approach is the adaptation of the loss function by weighting the classes when penalizing the loss (i.e. increasing the weight of the minority classes). Those class weights can be adjusted either w.r.t. the reciprocal of class frequency [inspired by King and Zeng, 2001] or w.r.t. the effective number of samples [Cui et al., 2019]. Lastly, we have explored the use of a focal loss function [Lin et al., 2020].Using balanced accuracy as a metric while minimizing the loss, we found that in our case adjusting the class weights in the loss function according to the reciprocal of the class frequency provides the best results. References:- RESIF, 2018: https://doi.org/10.15778/RESIF.RD- King, G., & Zeng, L. (2001). Logistic regression in rare events data. Political analysis, 9(2), 137-163.- Lin et al. (2020), Focal Loss for Dense Object Detection, IEEE TRANSACTIONS ON PATTERN ANALYSIS AND MACHINE INTELLIGENCE, VOL. 42, NO. 2, FEBRUARY 2020- Cui et al. (2019), Class-Balanced Loss Based on Effective Number of Samples, https://doi.org/10.48550/arXiv.1901.05555
The 2020-2023 La Niña: Did Cross-timescale Interference Fuel this Multi-year Event?
Authors: DiSera Laurel , Muñoz Ángel G.
Published: February 2023

Beginning July 2020, the Niño 3.4 index crossed below the threshold to La Niña conditions and remained below a -0.4 sea surface temperature anomaly through the spring of 2023, impacting agriculture, livelihoods, and communities around the world. What caused this prolonged La Niña event and why was it sustained? How did the interaction between the different modes of climate variability influence the event? The internal dynamics of ENSO, the Indian Ocean Dipole, and the Madden-Julian Oscillation are studied here through a non-linear approach utilizing compositing techniques and both linear and non-linear wave superposition to identify what caused and prolonged the 2020-2023 La Niña event.
Comparing the performance of process-based models for drought simulation in Scotland
Authors: Naha Shaini , Macleod Kit , Gagkas Zisis , Glendell Miriam
Published: February 2023

Scotland is increasingly vulnerable to periods of dry weather, impacting water users and the natural environment. In 2022, large parts of Scotland have experienced water scarcity, resulting in Scotland Environmental Protection Act (SEPA) suspending water abstractions for abstraction licence holders in some Scottish catchments. To understand and manage these water scarcity events in Scotland, we need to monitor and model the drought processes. This research is a part of a Scottish Government funded project ‘Understanding the vulnerabilities of Scotland’s water resources to drought’ which has been co-constructed with a range of national level stakeholders and aims to understand what the specific impacts of droughts are and what are the vulnerabilities that may apply to Scotland under future change. This includes the understanding of the spatial variability and characteristics of future hydrological drought events and short-term forecasting of drought duration to inform adaptive catchment management, while considering water resources requirements of different user sectors. As a first step towards constructing a national short-term drought forecasting framework, we have reviewed the state-of-the art hydrological modelling approaches currently applied in the UK. Our review suggests a lumped conceptual model, GR6J and a distributed hydrological response unit-based model, HYPE, are the most appropriate hydrological models for both simulating and short-term forecasting of droughts, based on the following criteria: openly available model code, proven ability at simulating and forecasting low flows, and widely used and supported model. In next steps, we will design a common modelling framework for drought simulation and forecasting in Scotland. Using both HYPE and GR6J, we will set up and test both models in a medium size long-term monitoring test catchment in Tarland in northeast Scotland (~70km2) where we have good process understanding and recent hydro climatological datasets. Comparison of the model performances of HYPE and GR6J will guide us to take a decision on which model to move forward with for upscaling in Scotland. Machine learning approaches for low-flow forecasting using long-short-memory networks will also be explored in developing a multi-model drought forecasting ensemble.  Keywords: Drought, water scarcity, modelling, HYPE, GR6J, forecasting 
Monitoring the climate change in the critical zone, Monte Rosa massif (Western Alps, Italy)
Authors: Giardino Marco , Baronetti Alice , Viani Cristina , Colombo Nicola , Freppaz Michele , Acquaotta Fiorella
Published: February 2023

Ongoing climate change is accelerating especially in high altitude areas that are the showing the fastest warming rates on Earth. High mountain territories like the European Alps are thus experiencing important changes among which modification in the water resource (e.g., amount, spatial and temporal distribution).Changes in snow accumulation in mountain areas caused by climate change are expected to have major impacts on water supply for adjacent lowlands, hydropower production or winter tourism. In addition, information of the amount of water stored within the annual snowpack (snow water equivalent, SWE) in high mountain regions is crucial for avalanche warning or mass balance calculations of glaciers.In the framework of the NODES (“Nord Ovest Digitale E Sostenibile”) Project and within the activities of the Laboratory of Alpine Climatology is ongoing the installation of an innovative weather stations in the high elevated areas of the Monte Rosa massif. The objectives of the projects are multiple: i) to fill the elevation gap of the present network of weather stations in the area, in order to better monitor the climate change within the Monte Rosa massif (particularly, focus is on air temperature and solid/liquid precipitation); ii) to install, test and compare innovative sensors for the analysis of snow water equivalent in order to contribute in the quantification of the water resource in the area; iii) analyzing the evolution and amount of seasonally snow accumulation caused by climate change  in high mountain regions to assess the risks and adaptation.Two weather station are going to be installed in summer 2023 at two different sites: at Passo dei Salati (3030 m a.s.l.) and on the Garstelet Glacier (about 3500 m a.sl.). They will be equipped with sensors for the measurements of the standard meteorological parameters and in addition they will be installed innovative sensors like Rocks, Finapp and GNSS ANAVS for the quantification of SWE. These instruments will allowed to measurement accurate measurements at a high temporal resolution.The actions put in place by our projects will accompany water management into the digital era, showing how digital technology can boost the integrated management of a vital resource e like water.
Comparison of wavelet- and FFT-based bathymetry retrieval methods and its application to nearshore X-band radar image sequenses
Authors: Chernyshov Pavel , Stresser Michael , Carrasco Ruben , Horstmann Jochen
Published: February 2023

Wavelet- and Fast Fourier Transform (FFT)-based methods for bathymetry retrieval from X-band radar image sequences are compared and analyzed. Both methods utilize the similar idea of the waves' phase shift estimation using cross-spectral analysis. Within the FFT-based approach the corresponding technique is used to determine wave vector's components from the image sequence frequency decomposition. The last means that the time FFT is applied to the original image sequence. Then for each frequency slice the corresponding wavenumber is derived applying the cross-spectrum analysis of the one pixel shifted images in the corresponding spatial direction. In such a way a set of wavevector-frequency (k, ω) pairs are formed and filtered according to a confidence criterion that reflects the stability of the local phase pattern. In the case of a wavelet-based method the corresponding cross-spectral analysis is applied to the 2D Continuous Wavelet Transform (CWT) directional complex spectra for pairs of successive images, resulting in a set of wavevector-celerity (k, c) pairs. Further, the corresponding set of pairs are fitted to the unknown depth using nonlinear least-square method and finite water depth linear dispersion relationship as a model. Weights proportional to the spectral power density and confidence values are used in the fitting process for the wavelet- and FFT-based methods correspondingly. Furthermore, both methods are verified by applying it to stochastic simulations of corresponding shoaling sea elevation image sequences and real X-band radar image sequences collected near the Hofn tidal inlet (Iceland). For the wave simulations, a linear solution of a mild slope equation is utilized. In order to accout for the effects ofthe ambient currents, a ray-tracing technique is applied. As a testing case, the shoaling of an incident JONSWAP spectrum-based wavefields are evaluated both on the following and opposing currents. A radar image model including tilt and shadowing modulations together with speckle noise is further applied to the modeled surface elevations. Both methods are able to reconstruct the original bathymetry for intermediate to shallow water depths (kph<1.2) with plausible accuracy both for all the synthetic cases (with varied probing geometries, bottom topography, ambient current, and sea state conditions) and real radar data case. In the last case, the accuracy of the FFT-based method is on the level 0.7-0.9 m in terms of the mean absolute error value with fairly small bias the standard deviation of the error is also less than 1 m in the whole area studied except the tidal channel, where the depth gradients are significantly larger. The wavelet-based method showes a higher bias with comparable mean absolute error and standard deviation.
Telecoupled impacts of Yudiba Dam on reforestation in the Loess Hill Ravine Region of northern Shaanxi
Authors: Wu Runqi , Xu Xiangzhou
Published: February 2023

Abstract: As a large-scale check dam, Yudiba Dam on the Loess Plateau of China, is a kind of check dam with the height more than 5 m which is used to retain soil and water, produce grain and control flood. The Yudiba dam plays an important role for vegetation restoration in the process of returning cropland to forest in the Loess Hill Ravine Region of northern Shaanxi. This study explores the telecoupling relationship between the check dam in Yulin, and the vegetation reforestation in the local and adjacent areas based on the statistical yearbook data and remote sensing data of the northern Shaanxi from 2000 to 2020. The results show that: (1) The normalized vegetation index (NDVI) of Yulin, Shaanxi Province, shows an increasing trend during 2001-2015. The NDVI is higher in the east of northern Shaanxi, Yulin, where the check dams are more concentrated, and shows a decreasing pattern in the west of northern Shaanxi where the check dams are more dispersed. The NDVIs of Mizhi, Suide and Qingjian counties in the east are 0.510, 0.511 and 0.520, respectively. The NDVI of Dingbian County in the west is only 0.354, while the NDVIs of Zizhou and Hengshan counties which are closer to the east, are 0.414 and 0.390, respectively. This indicates that the construction of Yudiba dam in Yulin significantly contributed to the growth of vegetation cover in local and other surrounding regions of Yulin. (2) Driven by the policy of returning cropland to forest in Shaanxi Province, the construction of Yudiba dam in the west of northern Shaanxi, e.g. Dingbian county, may be also strengthened because of the need of vegetation restoration. The construction of Yudiba dam will promote the infertile slope farmlands to be replaced with high-productivity check-dam farmlands in the west of northern Shaanxi. Hence the construction of Yudiba dam in Yulin may be helpful in realizing sustainable development of resource and environment in northern Shaanxi Province.Keywords: Telecoupling, Yudiba dam, sloping farmland, vegetation restoration, returning cropland to forest
Active and passive radar corner reflectors co-located with permanent GNSS stations in Sweden: Installation and performance
Authors: Nilfouroushan Faramarz , Gido Nureldin Ahmed Adam , Olsson Per-Anders , Puwakpitiya Gedara Chrishan
Published: February 2023

Artificial corner reflectors (CRs), passive (which have no electronic parts), or active ones, so called electronic CR (ECR) or compact transponders (CAT), are devices which reflect the radar signal back to the SAR satellites and provide measurement points at desired locations. Using, such devices we can measure temporal Line of sight (LOS) changes of the CRs using the InSAR technique and for example monitor the ground movements precisely.Since January 2020, Lantmäteriet, the Swedish mapping, cadastral and land registration authority, has installed three ECRs and several types of passive reflectors (different shape and size, planned for C-band Sentinel-1 satellites) in different locations in Sweden. So far, ECRs are still functioning with no electronic failure. However, from the ESA Geodetic SAR project (https://eo4society.esa.int/projects/sar-hsu/) we experienced that the ECRs electronic characteristics are different, so individual calibrations maybe required by the manufacturer. In addition, thermal effects may also cause problems for measurements with ECRs. Therefore, instead of installing more ECRs, we switched to passive ones which have no electronics and have already shown their high-quality performance in different studies. So far, we have installed ten CRs in different locations and the goal is to continue and complement the national geodetic infrastructure of Sweden with at least twenty passive reflectors which are co-located with permanent GNSS stations. Among others, these co-located corner reflectors can potentially contribute to the development of the national and European ground motion services in future updates. Moreover, the co-location helps to map the relative ground motions estimated with InSAR to an absolute geodetic reference frameAmong different tests and performance analysis of such reflectors, we did multipath analysis to investigate if our corner reflectors cause any multipath error on nearby GNSS stations.  We looked at the coordinate time series of the twin GNSS stations at two locations, Visby and Sveg. The installed corner reflector, double back-flipped squared, in Sveg is about 6 m away from the GNSS stations whereas, in Visby, the twin corner reflectors, ascending and descending, are about 20 meters away and have a trihedral squared trimmed shape. The daily GNSS coordinate time series for three components before and after installation of the corner reflectors didn’t show any significant jump in the time series and the coordinate variations are in the range of expected mm-level variations for all stations.
Highlighting the metasomatic impact on mottled UG-2 chromitites from the Bushveld Complex (South Africa) by large-scale µEDXRF mapping.
Authors: Rammlmair Dieter , Nikonow Wilhelm , Goldmann Simon
Published: February 2023

The use of µEDXRF elemental mapping provides access to data on relatively large core sections within a reasonable time at high spatial resolution down to 20 µm, enabling to link macroscopic to microscopic information, and providing an objective tool to select areas of interest for more sophisticated data acquisition by EPMA, LA-ICP-MS etc. Textural features can be visualized, that hardly are identified with the naked eye e.g. interstitial silicates in massive chromitites of the Bushveld Complex, South Africa. The application of automated mineralogy provides access to local paragenetic changes and to modal analyses of selected areas. Automated mineralogy based on µEDXRF has to overcome a number of obstacles due to aspects of diffraction, depth of information and grain boundary effects. Tools have been developed to limit these aspects within an acceptable error frame by combining the information of two opposing detectors to reduce the side effects of diffraction. By applying a supervised endmember based classification using the spectral angle mapper algorithm of the ENVI hyperspectral software, phase distribution maps can be produced. Within a well-known system such as the UG-2 chromitite mineral names can be attributed to the identified phases. Exceptions exist for very fine grained secondary phases which might show mixed signals. Well-identified phases can be segmented and grain size, shape and orientation of individual grains can be obtained supported by diffraction signals of single grains. Chemical information can further be extracted for individual minerals, individual grains and bulk area corresponding to the modal mineralogy for any selected area. This offers a new approach to interprete (Verb fehlt?) complex textures by comparing chemical and mineralogical aspects of individual textural pattern. The example of mottled UG-2 chromite shows that the hosting silicates of the chromititebasically orthopyroxene and anorthite-rich plagioclase, but within stringers phlogopite, anorthite-poor plagioclase, potassic feldspar, amphibole, quartz with local enrichment of apatite and sulphides, show differences in grain size and chemistry of the chromite. EPMA investigations on chromite show that Cr/(Cr+Al), Mg/(Mg+Fe), and Cr/Fe is controlled by the chemistry of its hosting oikocryst silicates plagioclase or orthopyroxene. The appearance of late inter-oikocryst phlogopites induces a metasomatic loss of titanium in the chromite. By applying several steps of µEDXRF data reduction and phase masking, these changes in chromite chemistry can be visualized despite of the relatively large spot size of 20 µm for large areas. Using this information the metasomatic impact within a continuously µEDXRF mapped half drill core can be visualized and quantified. 
International Tracing Events 2021-2023 – Discussion and developments in sediment tracing
Authors: Kraushaar Sabine , Evrard Olivier , “International Tracing Day” participants All of the
Published: February 2023

Several innovative techniques have been developed recently opening up new avenues to establish the assessment of sediment flux in the critical zone. These techniques include the tracing or “fingerprinting” methods to identify sediment sources and quantify the dynamics of particle-bound contaminants. However, the use of these techniques is often associated with several methodological and statistical limitations, that are often reported by the international scientific community but rarely addressed in the framework of concerted actions.This presentation will highlight the main developments and outcomes of the “International Tracing Day” 2022 and 2023, and the Tracing School organised in 2021. Based on the publication of an opinion paper (https://link.springer.com/article/10.1007/s11368-022-03203-1), new strategies to publish and disseminate sediment tracing databases will be presented. An example of a formatted dataset will be given, with the objective to test research hypotheses based on multiple datasets adopting the same format of data and meta-data. Other perspectives regarding improvements of the sediment fingerprinting method in terms of modelling, tracer options and selection will also be presented.
Earthquake Detection and Location in the Cameroon Temporary Network Data Using Deep Learning
Authors: Carvalho Luis , Mohammadigheymasi Hamzeh , Crocker Paul , Tavakolizadeh Nasrin , Moradichaleshtori Yahya , Fernandes Rui
Published: February 2023

A temporary seismic network consisting of 32 broadband seismic sensors was installed in Cameroon between March 2005 and December 2006 to study the seismic structure of the crust and upper mantle beneath the Cameroon Volcanic Line (CVL). This study aims to re-evaluate the seismicity in this period by processing this database and calculating an updated crustal velocity model for the region incorporating the acquired earthquake bulletin. The earthquake detection and location procedure applies hybrid deep learning (DL) and phase validation methods. We use an integrated workflow composed of Earthquake Transformer (EqT) and Siamese Earthquake Transformer (S-EqT) for initial earthquake detection and phase picking. Then, PickNet is used as a phase refinement step, and REAL for earthquake association and rough location. A set of thresholding parameters for earthquake detection and P- and S-picking equal to 0.2 and 0.07 are adjusted, respectively. By combining a set of 33282 P and 29251 S-picked phases associated with 743 earthquakes with 1.3 ≤ ML ≤ 4.6, we implement a joint inversion for estimating an updated 1D crustal velocity model. The obtained mode comprises thicknesses of 8, 12, 14, 20, and 30km, from the surface to a depth of 45km, with Vp = 6.1, 6.4, 6.6, 7.6, 8.25, and 8.5km/s, respectively. The newly detected events are primarily concentrated in three main clusters, 1) the east flank of Mount Cameroon, 2) an area between Mount Cameroon and Bioko Island, and 3) southern Bioko Island. The compiled catalog for this time interval is 1.7 times larger than the already reported catalog for this data set. Finally, we present a 3D time-lapsed animation of the detected earthquake sequences.Acknowledgements: The authors would like to thank the support of the Instituto de Telecomunicações. This work is funded by FCT/MCTES through national funds and, when applicable co-funded EU funds under the project UIDB/50008/2020.
Contrasting saltmarsh vegetation impacts under increasing sea level rise rates
Authors: Gourgue Olivier , Xu Yiyang , Belliard Jean-Philippe , van Belzen Jim , van de Koppel Johan , Kleinhans Maarten G. , Fagherazzi Sergio , Temmerman Stijn
Published: February 2023

The resilience of saltmarshes mainly depends on their ability to gain elevation by sediment accretion to keep pace with sea level rise. While vegetation is known to facilitate sediment accretion at the plant scale by trapping mineral sediments and producing organic matter, the long-term impact at the landscape scale is still poorly understood. Here we use the biogeomorphic model Demeter to reveal contrasting vegetation impacts on spatial patterns of sediment accretion under different sea level rise regimes. Under contemporary sea level rise rates (2-10 mm/yr), vegetation inhibits sediment transport from tidal channels to platform interiors and creates levee-depression patterns. Hence, intertidal platforms accrete slower with vegetation than without, but this trend attenuates with increasing sea level rise rate, as water depth increases, and vegetation drag decreases. Under extreme sea level rise rate (20 mm/yr), platform interiors don’t keep up and turn into open water, while vegetation allows to preserve intertidal levees. Our results help to better understand some basic biophysical mechanisms that will control the fate of coastal wetlands under global climate change.