bluuebunny/crossref_metadata_2025 huggingface dataset:
Integrating urban development and stormwater management; Car parking allocation in north of Finland
Authors: Rossi Pekka M. , Hosseinzadeh Azadeh , Torabi Haghighi Ali , Jalali Shahrood Abolfazl , Outila Tarja , Jutila Johannes
Published: March 2022

Intensified urbanization and climate change alter natural water systems, resulting in urban flooding. To overcome this issue, urban development decisions should align with resiliency needs including stormwater management. Integrating stormwater management within urban planning helps us to design more sustainable alternative systems. Developing vacant or underused areas which leads to changes of imperviousness percentage, hence influences runoff volume, is a key action in urban development. We investigated the effect of car parking allocation on stormwater management in urban areas. In this analysis, several car parking allocation scenarios are considered for this analysis in three independent urban areas in Oulu, northern Finland. These areas are encountering some changes in land use and new construction based on their approved detailed plan. We used a calibrated Stormwater Management Model (SWMM) to simulate different redevelopment scenarios. In this study, impact of climate change is addressed by comparing a range of precipitation values. Based on the results a promising structure is provided that decreases flooded areas in the future. Results indicate, that we can conduct stormwater flood management more efficiently by changing regulations in urban planning in the context of car parking, which helps us construct more green infrastructure instead of grey ones; in addition, changes in people's mobility habits and behavior which is affected on urban structure indirectly contributes to stormwater control.
Reduction in NOX emissions during the COVID-19 lockdown did not result in a comparable reduction in secondary PM levels
Authors: Balamurugan Vigneshkumar , Chen Jia , Qu Zhen , Bi Xiao , Keutsch Frank N.
Published: March 2022

The COVID-19 lockdown is viewed as a natural experiment that can put our current understanding of the contribution of secondary PM2.5 sources to the test. In ten German metropolitan areas, mean meteorology-accounted for PM2.5 concentrations dropped by 5 % during the 2020 lockdown period (spring) compared to 2019, but meteorology-accounted for NO2 concentrations decreased by 23 % during the same time. Furthermore, meteorology-accounted for SO2 and CO concentrations show no significant differences between the 2020 lockdown period and 2019. The GEOS-Chem model simulation with COVID-19 emission reduction scenario (23 % reduction in NOX emission with unchanged VOC and SO2) supports our findings of only a marginal decrease in PM2.5 and a significant decrease in NO2 levels and reveals that the atmosphere's oxidative capacity is increased in all three important oxidants, OH, O3, and night-time NO3. The night-time increase in O3 is the main cause of increase in night-time NO3 radical. The increase in OH does not compensate for the strong reductions in NO2, whereas the increase in NO3 radical at night roughly balances the effects of the NO2 reduction. As a result, compared to the Business As Usual condition, i.e., no lockdown, day-time PM nitrates are reduced while night-time PM nitrate formation is relatively unaffected. In addition to the above, slightly enhanced sulfate formation and decreased ammonium explain the small reduction in the total PM2.5 during the lockdown period. We also investigated the annual spring high PM2.5 episodes in German metropolitan areas. Satellite measurements show high ammonia (NH3) concentrations in the early spring and summer months, when high PM2.5 episodes are associated with high NH3 concentrations in the spring. We find that high atmospheric ammonia concentrations, combined with low temperature and low boundary layer height, are the most favorable conditions for PM2.5 formation. Based on our findings, we suggest that emission control policies should be more focused on limiting ozone that should also reduce PM2.5. Furthermore, ammonia emissions should be limited in order to control the high PM2.5 episodes in winter and spring.
Alkalinity Production Coupled to Pyrite FormationRepresents an Unaccounted Blue Carbon Sink
Authors: Reithmaier Gloria , Johnston Scott G. , Junginger Tobias , Goddard Madeline M. , Sanders Christian J. , Hutley Lindsay B. , Ho David T. , Maher Damien
Published: March 2022

Blue carbon ecosystems, including mangroves, saltmarshes, and seagrasses, mitigate climate
change by storing atmospheric carbon. Previous blue carbon research has focused on organic carbon
stocks. However, recent studies suggest that lateral inorganic carbon export might be equally important.
Lateral export is a long-term carbon sink if carbon is exported as alkalinity (TAlk) produced via sulfate
reduction coupled to pyrite formation. This study evaluates drivers of pyrite formation in blue carbon
ecosystems, compares pyrite production to TAlk outwelling rates, and estimates global pyrite stocks in
mangroves. We quantified pyrite stocks in mangroves, saltmarshes, and seagrasses along a latitudinal
gradient on the Australian East Coast, including a mangrove dieback area, and in the Everglades
(Florida, USA). Our results indicate that pyrite stocks were driven by a combination of biomass, tidal
amplitude, sediment organic carbon, sediment accumulation rates, rainfall, latitude, temperature, and
iron availability. Pyrite stocks were three-times higher in mangroves (103 ± 61 Mg/ha) than in saltmarshes
(30 ± 30 Mg/ha) and seagrasses (32 ± 1 Mg/ha). Mangrove pyrite stocks were linearly correlated to
TAlk export at sites where sulfate reduction was the dominant TAlk producing process. However, pyrite
generation could not explain all TAlk outwelling. We present the first global model estimating pyrite
stocks in mangroves, giving a first-order estimate of 197 Mg/ha (RMSE = 24 Mg/ha). In mangroves,
estimated global TAlk production coupled to pyrite formation (∼3 mol/m2/y) is equal to ∼24% of their
global carbon burial rate, highlighting the importance of including TAlk export in future blue carbon
budgets.
Combination of integral transforms by spectral weighting – an overview  
Authors: Pitoňák Martin , Šprlák Michal , Novák Pavel
Published: March 2022

Geodetic boundary-value problems (BVPs) and their solutions represent an important tool for describing and modelling potential fields such as the Earth’s gravitational field. Solutions to spherical geodetic BVPs lead to spherical harmonic series or surface convolution integrals with Green’s kernel functions. New BVPs have recently been formulated reflecting development of sensors. BVPs have been also developed for observables measured by kinematic sensors on moving platforms, i.e., airplanes and satellites. Solutions to BVPs for higher-order derivatives of the gravitational potential as boundary conditions are represented by multiple integral transforms. For example, solutions to gravimetric, gradiometric and gravitational curvature BVPs are represented by two, three and four integral transforms, respectively. Theoretically, each of the nine transforms provides an identical value of the gravitational potential, but practically, when discrete noisy observations are exploited, they provide different estimates. Combination of solutions to the above mentioned geodetic BVPs in terms of surface integrals with Green’s kernel functions by a spectral method is investigated in this contribution. It is assumed that the first-, second- and third-order directional derivatives of the Earth’s gravitational potential can be measured at the satellite altitude. They are downward continued to the Earth’s surface and converted into height anomalies. Thus, the spectral combination method serves in our numerical procedure also as the downward continuation technique. The spectral combination method requires deriving corresponding spectral weights for all nine estimators. A generalized formula for evaluation of spectral weights for the estimators is formulated. Properties of spectral combinations are investigated in both spatial and spectral domains.
Assessing phosphorus availability to paddy rice: soil testing and plant responses 
Authors: Martinengo Sara , Schiavon Michela , Santoro Veronica , Said-Pullicino Daniel , Celi Luisella , Martin Maria
Published: March 2022

The optimization of P fertilization in paddy rice fields requires an accurate estimation of soil P availability to balance rice productivity and ecosystem preservation.  While there are several generally accepted methods to evaluate P availability to crops grown in aerobic soils, the available P pool in paddy soils cannot be so easily assessed. Phosphorus cycle in paddy soils is closely linked to Fe redox wheel and conditioned by the complex interactions between soil characteristics and plant strategies to promote P uptake. The aim of this study was the identification of the method that best estimates P availability for rice plants while taking into account the complex interactions between soil (bio)geochemistry and plant responses.

Twelve representative paddy soils have been selected and analyzed for available P with different methods (calcium chloride, Olsen, Mehlich-3, anion exchanging resins, EDTA, citrate/ascorbate and oxalate). In the same soils, rice plants were grown for 60 days; during this period temporal variation of soluble P and Fe(II) in the soil solution was monitored. The plants were then harvested and the roots and shoots biomass, the P content in plant tissues, the expression of the root phosphate transporter encoding genes and the root activity of phytase and phosphatase were determined.

During the growing period, the soluble P concentration in the soil solution increased during the first 3-4 weeks, following the same trend of Fe(II), then it decreased, probably due to plant uptake and P-Fe co-precipitation. Both biomass and P concentration in the tissues were affected by soil P content. The extraction with resins was the best predictor for plant productivity and P uptake, followed by CaCl2 and Olsen extraction. The extractants involving the partial dissolution of the sorbing minerals (i.e., oxalate and citrate/ascorbate) showed a poorer, although still significant correlation with P concentration in rice plants, but a higher performance in terms of organic P. Phosphatase activity was greater than phytase in all cases; the former did not significantly differ among soils, while the latter was higher in those soils releasing more P in solution during the growing period and was correlated with P concentration in plants. In low P soils a higher expression of root transporter encoding genes was observed, particularly those at high-affinity.

Although resins, CaCl2 and Olsen extractions are confirmed as useful tools for the prediction of P availability even for paddy rice cultivation, in P-deficient soils the enhancement of enzymatic activity and the overexpression of root P-transporters increased the capacity of plant P uptake above the prediction of the chemical extractants.
CH4 emission preprocessing for high resolution modelling of concentrations with the ICON-ART model
Authors: Roth Franziska , Mamtimin Buhalqem , Sunkisala Anusha , Kaiser-Weiss Andrea
Published: March 2022

Linking reported anthropogenic emissions of greenhouse gases, as, e.g., methane, to observed concentrations requires the appropriate modelling of the meteorological transport. Starting from spatially highly resolved emissions provided by Copernicus and TNO for Europe as well as the emissions from Germany provided by Germany's central environmental authority (UBA) we employ the DWD’s Icosahedral Nonhydrostatic (ICON) model with its transport scheme ART (Aerosols and Reactive Trace gases) extension for forward modelling of methane concentrations.

This requires a preprocessing, i.e., mapping of point sources and area sources to the target ICON grid, and considering the resulting uncertainties appropriately. We investigate the scales of the various tiers of government for Germany, namely counties and federal states of Germany. On one hand, this is the inherent spatial resolution with which emissions are reported for some sectors. On the other hand, this is the scale where interpretation of modelling results are of interest for subsequent objective verification of inventories and demonstration of success of mitigation measures. In this work, we discuss the uncertainties arising from preprocessing reported methane emissions for various sectors and compare to the uncertainty inherent in the spatial resolution of the inventories.

The results show our preprocessing is useful for simulating the CH4 atmospheric concentrations at a regional scale.

This work is financially supported by the project HoTC funded by the German Federal Ministry for Digital and Transport.
Mobilization of black and white ashes by overland flow and their retention by riparian vegetation - preliminary results from a lysimeter experiment
Authors: Macedo Godoy Leandro , Beatriz Simões Liliana , Machado Ana Isabel , Martins Ricardo , Campos Isabel , Jacob Keizer Jan
Published: March 2022

Wildfires are now widely documented to produce strong to extreme runoff and erosion responses during the so-called window-of-disturbance. However, the role of wildfire ash in post-fire runoff generation and especially the contribution of wildfire ash to post-fire erosion rates are still poorly studied. The same applies for the effectiveness of erosion control measures to reduce ash mobilization by runoff. To address these knowledge gaps, we carried out a lysimeter experiment in which overland flow and the associated transport of sediments and ashes was compared for five treatments. Four treatments involved the application of black ash from a wildfire or white ash from a paper pulp factory, both with and without a simulated riparian strip at the bottom of the slope, while the fifth treatment was the control without ash as well as without the riparian strip. Each of the five treatments was applied to three randomly selected lysimeters. The lysimeters had a surface area of 50 cm by 120 cm, a slope angle of approximately 10 degrees and were topped up with a 2-3cm-thick layer of soil (in fact, sediments from the Mondego river) over a sand and a gravel layer. Overland flow was collected at the bottom of the lysimeters and diverted into a tank using a garden hose. The experiment started on 6 September 2021 with the application of the ash at a rate of 500 g m-2 and ended on 22 October 2021, coinciding with the initial phase of the post-fire window-of-disturbance in the study region. During this 7-week period, overland flow was measured at a total of five occasions following significant rainfall events and, whenever possible, samples collected for laboratory analysis of their concentration of total suspended sediment (TSS) and their organic matter fractions.  The preliminary results for the lysimeters without riparian strip suggested that the two types of ashes played contrasting roles in overland flow generation. The average amount of overland flow over the 7-week period was higher for the lysimeters with white ashes than for the control lysimeters (36.0 vs. 31.2 l), while the opposite was true for the lysimeters with black ashes (26.8 l). These differences in overland flow were associated with differences in TSS concentrations that were the opposite, averaging 11.7 and 20.4 g l-1 over the entire study period in the case of the lysimeters with white and black ashes, respectively. The overall TSS concentrations also suggested a marked role for the riparian strips but only in the case of the black ashes, dropping to 15.3 g l-1. In the case of the white ashes, the overall TSS concentrations were the same with as without the riparian strips.
P-to-S receiver function imaging of the Alpine Mantle Transition Zone using AlpArray Seismic Network
Authors: Tharimena Saikiran , Agius Matthew , Hetényi György , Bokelmann Götz
Published: March 2022

The Mantle Transition Zone (MTZ), the region between 410 km and 660 km depth, is vital for the Earth’s thermal and chemical evolution. The thickness of the Mantle Transition Zone (MTZ), and seismic anomalies in this region could hold clues to its current thermal and chemical state. The seismic structure of MTZ is inferred from P-to-S (Ps) receiver function imaging, using data from 723 stations from 2016 – 2020, covering a much larger area of the Alpine region than previously imaged. A total of 1368 events with magnitude > 5.5 Mw, and a distance range of 35 to 80 degrees were used. Seismic records were pre-processed to remove instrument response, filtered using a zero-phase second order Butterworth filter with cut-off frequencies at 0.025 and 0.2 Hz, followed by rotation to ZRT and LQT system. Ps receiver functions were computed by deconvolving traces with clear P-wave phase from radial (R) and SV components (Q). Iterative time domain deconvolution and extended time multi-taper frequency domain deconvolution were used. Waves with clear P-, P410s, and P660s were selected and migrated to depth using a smoothed 1D velocity model for the AlpArray region derived from EU60 seismic model for the crust and upper mantle, and IASP91 for the deeper regions. Observations of the Moho from Ps receiver functions are consistent with global and regional crustal thickness estimates. The Alpine MTZ shows evidence for subduction of the European plate in the western Alps. Punctuated anomalies beneath the Alpine region, indicated by the deflection of the 410 km and 660 km discontinuities, show evidence of slab from past subduction events reaching the MTZ, consistent with previous regional studies. Further analysis could provide clues to the dipping orientation of the subducted slab.
Seismic velocity changes prior to the 2018 eruption of Sierra Negra volcano, Galapagos Island, using coda wave interferometry.
Authors: Longobardi Mariantonietta , Bean Christopher J , Bell Andrew Forbes , Ruiz Mario Calixto , Grannell James , Hernandez Stephen
Published: March 2022

Changes in external stress state and fluid content alter the mechanical properties of an elastic medium. Hence, variations in seismic wave velocity and (crack-induced) seismic anisotropy can be used as proxies for changes in stress and possible fluid ingression. Temporal variations in seismic wave velocity have previously been monitored and observed prior to volcanic eruptions. In the absence of additional constraints related to stress or fluid changes on the volcano, these pre-eruptive changes are difficult to interpret and hence their causes are often not well understood.

Sierra Negra volcano is one of the most active volcanoes on the Galapagos Islands, about 1000 km west of continental Ecuador. On 26th June 2018 at 09:15 UTC, a magnitude 5.4 earthquake occurred near the southwest caldera rim and an intense seismic swarm started around 17:15 UTC. Seismic tremor dominated at about 19:35 UTC, which marked the onset of the eruption. Both prior to and during the eruption period several families of repeating earthquakes have been identified in a very large seismicity sequence.

In this study, we use the Coda Wave Interferometry (CWI) technique on repeating earthquakes to measure time-lapse changes in seismic velocity prior to the 2018 eruption.

We used 3 months of continuous seismic data from different temporary broadband stations, and 1 year of data from one of six permanent stations, the VCH1 station located on the caldera rim, managed by the IGEPN.

Our results show a decrease in the seismic velocities observed from June 2017 to June 2018. In particular, we see a large systematic decrease in velocity starting up to a year before the eruption. A large velocity decrease of almost 2% is detected, over the year preceding the 2018 eruption at Sierra Negra. We suggest that this is related to progressive damage of the edifice, as it continues to inflate.
Alder-induced stimulation of soil gross nitrogen turnover in permafrost-affected peatlands of Northeast China
Authors: Ramm Elisabeth , Liu Chunyan , Mueller Carsten W. , Gschwendtner Silvia , Yue Hongyu , Wang Xianwei , Bachmann Juliane , Bohnhoff Joost A. , Ostler Ulrike , Schloter Michael , Rennenberg Heinz , Dannenmann Michael
Published: March 2022

Unlike carbon dynamics, nitrogen (N) dynamics in permafrost peatlands are not well-studied. For the prediction of permafrost N climate feedbacks, a better process-based understanding of the N cycle in permafrost peatlands is however urgently needed. Therefore, we characterized and quantified soil organic matter, soil gross microbial N turnover and soil-atmosphere exchange of nitrous oxide (N2O) on the southern edge of the Eurasian permafrost area in situ (www.nifroclim.de). Specifically, we sampled a tree-free lowland peatland and a lowland peatland with an N2-fixing alder forest in Northeast China.

Nuclear magnetic resonance spectroscopy revealed more recalcitrant organic matter at greater depth and more bioavailable organic matter substrates in upper peat horizons. In line with this result, gross ammonification and nitrification generally decreased with increasing sampling depth. Gross rates of mineral N turnover in the active layers of the tree-free peatland were comparable to those of temperate ecosystems. Despite substantial gross ammonification, the low nitrification:ammonification ratios and negligible soil N2O emissions still depicted a closed N cycle characterized by N limitation in the tree-free peatland.

In strong contrast, the peatland underneath the alder forest showed an accelerated N turnover with very high gross rates of ammonification (3.1 g N m-2 d-1) and nitrification (0.6 g N m-2 d-1), exceeding those of the alder-free peatland by an order of magnitude. This was accompanied by substantial N2O emissions. The increase in gross N turnover was most pronounced in the rooted soil layer, where N inputs from biological N fixation almost doubled total N concentrations and halved the ratios of soil organic carbon to total N. The frozen ground underneath alder trees contained strongly increased ammonium concentrations prone to be released upon thaw. This study shows that alder forests that further expand on permafrost-affected peatlands with global change create hot spots of soil mineral N turnover, thereby potentially enhancing permafrost N climate feedbacks.
Climate-Benign Direct Air CO2 Capture, Utilization, and Storage (DACCUS) 
Authors: Leveni Martina , Bielicki Jeffrey M.
Published: March 2022

Transitioning towards a carbon managed energy infrastructure is essential to mitigate climate change. Negative emission technologies, such as direct air CO2 capture (DACC), together with renewable energies will likely to be necessary components in the effort to slow, stop, reverse the flow of carbon dioxide (CO2) to the atmosphere. The DACC process requires heat and electricity to capture CO2 from the ambient air, the sources of which may not be climate-benign. We present an approach that combines DACC, long-term CO2 storage, and geothermal energy production: a climate-benign direct air capture, carbon utilization, and storage (DACCUS). The CO2 captured from the ambient air, is geologically stored in sedimentary basins, and circulated to the surface in a closed system to extract the available geothermal heat.  The produced heat can be used directly or converted to electricity by a power plant and used in the DACC process.  We investigate the performance of DACCUS systems, including sensitivity analyses of key parameters, such as the sorbent regeneration temperature (80-120°C), the outlet temperature the CO2 stream from the DACC (70-22°C), and reservoir permeability (1x10-15-1x10-11 m2), among others.  The results indicate that DACCUS has a promising potential for using the CO2 from DACC to produce process energy requirements. For example, with a regeneration temperature of 100°C and a DACC outlet temperature of 70°C, reservoirs with depths equal or above 3.5 km, and geothermal temperature gradients equal or above 35°C/km, can provide sufficient wellhead temperatures. In addition, the maximum DACC capacity for those temperatures increases considerably for reservoir permeability up to 5x10-14 m2, and can provide the make-up CO2 for that which migrates outside of the region in the aquifer where CO2 is circulated between the subsurface and the surface. Costs estimates for DACC are $500–600/tCO2. While also the cost of the integrated system is important, the integration with CO2-geothermal production could yield substantial savings for DACC ($0.64M - $30.6M annually of avoided electricity costs). 

 
Plate boundary deformation of the eastern Hellenic arc inferred from analysis of lineaments, Island of Rhodes, Greece 
Authors: Ferreira Malu , Riller Ulrich
Published: March 2022

The restricted exposure of crust above sea level limits the studies of plate boundary deformation and kinematics in the eastern Mediterranean. Specifically, the relative importance of vertical and horizontal displacements on prominent faults of the eastern Hellenic arc, characterized by oblique plate convergence, is uncertain. Focusing on the Island of Rhodes, which is part of the outer Hellenic arc, a GIS-based lineament analysis unveiled distinct kinematic regimes of deformation. A total of 1054 morphological lineaments were extracted using digital terrane, shaded relief, slope, flow, and drainage maps that were generated from a 30 m resolution digital elevation model. The extracted lineaments are remarkably uniform in trend and can be grouped into five sets. Based on the similarity of trends, lineaments of three sets can be related to traces of faults with known slip senses. In contrast to the results of a previous lineament study from the westernmost part of Rhodes, NNW-trending lineaments turned out to be the most prominent ones in the entire extension of the island. Lineaments of this set are parallel to traces of right-lateral strike-slip faults. By contrast, two sets of eastward-trending lineaments conform to traces of faults characterized chiefly by components of dextral and normal sense-of-slip. Collectively, the lineament sets point to two kinematically distinct deformation regimes. Alternatively, the lineament sets may have formed simultaneously due to slip partitioning. In this case, the upper crust may have been segmented into rhomb-shaped domains separated by individual lineament sets. Interestingly, none of the lineament sets fits the trends of subsidiary discontinuities of a master sinistral strike-slip system that is parallel to the plate boundary. Thus, the formation of the sets seems more compatible with the overall horizontal extension of the upper crust than with margin-parallel shear caused by oblique plate convergence.
Estimation of tropospheric biases in SLR to Swarm, and LAGEOS satellites
Authors: Strugarek Dariusz , Drożdżewski Mateusz , Sośnica Krzysztof , Zajdel Radosław , Bury Grzegorz
Published: March 2022

Satellite Laser Ranging (SLR) is the only one space geodetic technique in which troposphere correction is calculated based on in situ measurements (pressure, temperature, and humidity) and used in the least square adjustment process as a fixed value measured at the epoch of observation.  In the past few years, we observe that the use of malfunctioning barometers for some of the SLR stations significantly affects the SLR-based global geodetic parameter estimates, such as station coordinates, geocenter coordinates, and terrestrial reference frame scale. Thus, we examine different handling of the SLR range tropospheric delay to LAGEOS by analysing the a priori zenith total delay from the standard Mendes and Pavlis (2004) model with a corresponding mapping function, the estimated tropospheric correction, and the range bias parameter. Moreover, we conduct a simulation study of artificial pressure bias, investigating the capability of tested approaches to properly reconstruct the tropospheric error. The new approach based on the estimation of the troposphere delay correction for SLR solutions, which is also widely used in microwave techniques, explicitly demonstrates more suitable handling of errors affecting the SLR station than solutions based on estimation of range biases.

The progress in precise orbit determination of low Earth orbiter (LEO) satellites using GPS demands improvements of the SLR procedures considering their orbit validation, determination of station coordinates, and global geodetic parameters from SLR to LEOs solutions. Within this study, we also consider including the proper handling of range errors in SLR to LEOs. We test solutions incorporating the estimation of tropospheric biases with and without horizontal gradients, range biases, and station coordinate corrections in an example of the SLR observations to LEO Swarm satellites. We discuss the values of estimated corrections and their impact on the solution quality, and dependency of residuals to different measurement conditions, such as elevation angle, azimuth angle, station-satellite distance, or satellite view from a station. Estimating tropospheric biases once-per-day and horizontal gradients, absorbs elevation- and azimuth-dependent errors, provides a reduction of solution statistics, and dependency of SLR residuals for almost all used SLR stations.
Revisiting stylolites as a gage of overburden pressure – insights from fractal analysis
Authors: von Hagke Christoph , Hirländer Simon , Frings Kevin , Madritsch Herfried
Published: March 2022

Stylolites are ubiquitous structures generated by pressure solution primarily found in limestones. They and have been used as indicator for maximum stress a rock has suffered. This is commonly done by characterizing the fractal dimensions of stylolites. The current canon is the expectation from the theory that stylolites form through two physical pressure-driven regimes: low-frequency and higher-energetic - dominated by elastic forces and high-frequency lower-energetic dominated by surface tension. The so-called characteristic length separates both regimes, analytically marked by a kink in the power spectrum, which relates the energy contributions to the frequency.

However, determining this kink is not straightforward, and requires additional assumptions. We present a data set of stylolites recovered from a drill hole in the Alpine foreland basin. We mapped stylolites from different depths at sub-mm resolution semi-automatically and analyzed them using new methods of fractal analysis.

Excitingly, our preliminary studies did not identify the expected kink’s position from several different images of probes of drill cores, despite satisfactory reliability of laboratory preparation. Standard methods such as power spectral density, averaging wavelet coefficients, RMS, min/max, and rescaled range-based approaches revealed variations in their results, generally without evidence for a kink in the corresponding graphs. Implementing more recently developed methods such as adaptive fractal analysis could not improve the results. This finding challenges the classic interpretation of fractal characteristics of stylolites. 
The implementation of the Forest Canopy Density (FCD) model for Coniferous ecosystems in Cyprus forests, using Landsat-8 and Sentinel-2 satellite data.
Authors: Prodromou Maria , Gitas Ioannis , Themistocleous Kyriacos , Hadjimitsis Diofantos
Published: March 2022

The canopy of trees plays a very important role in forest ecosystems and acts as a regulator, as it is a factor that affects the microclimate and the soil conditions. The density of the forest canopy is associated with forest development, and it is a factor that can indicate the degree of forest degradation. Additionally, forest density is one of the most important parameters, used in the design and implementation of programs for forest restoration, especially in cases of areas affected by fires. The main objective of this study is to determine the disturbance that occurred in the canopy density after the fire events that occurred in Argaka and Solea villages in June 2016 at Paphos forest and Adelfoi forest respectively, in Cyprus. For the purposes of this study, the Forest Canopy Density model (FCD model) was estimated using the Landsat-8 satellite data. Moreover, this study aimed to evaluate the FCD using Sentinel-2 data. The results obtained from Sentinel-2 seem to be very promising and the calculation of the canopy density through this study is achieved in a better resolution, in contrast to the analysis available by the Landsat-8 satellite. This work has been supported by the project ‘ERATOSTHENES: Excellence Research Centre for Earth Surveillance and Space-Based Monitoring of the Environment-EXCELSIOR’ (https://excelsior2020.eu/) that has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 857510 (Call: WIDESPREAD-01-2018-2019 Teaming) and from the  Government of the  Republic of  Cyprus through the Directorate-General for the  European  Programmes,  Coordination, and  Development.
Sediment routing though the apex of a mega-delta under future anthropogenic impacts and climate change 
Authors: Le Quan Quan , Vasilopoulos Grigorios , Hackney Christopher , Parsons Daniel , Nguyen Nghia Hung , Darby Stephen , Houseago Robert
Published: March 2022

Deltas are home to 4.5% of the global population and support a range of ecosystem services that are vital to lives and livelihoods. As low-lying regions, deltas are also amongst the most vulnerable areas to the threat climate change and relative sea-level rise, which are being exacerbated by ongoing local resource exploitation. Anthropogenic activities such as riverine sand mining, construction of flood embankments, deforestation and changes of land use and hydropower dams are disrupting the natural evolution of deltaic systems, with many of the world’s large deltas now being sediment starved. This is important because changes of the sediment flux into large deltas can have implications for the evolution of the morphology of delta bifurcations and their function at routing water and sediment seaward. This can amplify flood hazard and risk for riparian communities and intensify processes such as bank erosion, presenting hazards to human lives and exacerbating land loss. The present study focuses on the Chaktomuk junction at the apex of the Mekong delta, connecting the Mekong with the Tonle Sap Lake and the downstream delta. The junction is important as it provides the connection between the Mekong and the largest freshwater lake in Southeast Asia and because of the proximity of the junction to the rapidly expanding urban centre of Phnom Penh. We present a combined 2D hydrodynamic and sediment transport model for the Chaktomuk junction, constructed and based on high-resolution bathymetric data obtained with multibeam echosounders. A series of established sediment transport equations are adopted and tested through a sensitivity analysis to identify the most appropriate sediment transport solver for the model, which is then validated against field observations. The model was forced with a series of scenario combinations including changes of water and sediment flux and rates of sand mining. Simulation runs are presented that project the future evolution of the apex of the Mekong delta, including changes in bifurcation morphology, water and sediment routing seaward through delta distributary channels and changes in water and sediment exchanges between the Mekong and the Tonle Sap. The implications of these future trajectories will be discussed in terms of the sustainability of the delta to future change.
A conceptual workflow for cost-benefit analysis of flood polders along the Bavarian Danube.
Authors: Hoffmann Amelie , Straub Daniel
Published: March 2022

As part of the Bavarian flood protection program 2020plus, a system of controlled flood polders is planned along the Danube River in order to reduce the risk associated with overload flood events and avoid catastrophic flooding. Flood polders work by reducing the maximum discharge during very large flood events, thereby relieving stress on downstream river dikes. Thus, flood polders can effectively contribute to preventing the occurrence of dike breaches.

Since flood polders are expensive to implement, their economic efficiency is investigated using cost-benefit analysis (CBA). The CBA weighs all societal costs against the monetized benefits in the form of an economic efficiency criterion. Different challenges arise in the evaluation. In particular, requirements for data availability and consistency are difficult to meet when evaluating protection measures that are located in and take effect across different agency jurisdictions. Because the CBA has to be conducted within a fixed time frame and budget, it must use models that can work with readily available data. Furthermore, the future effectiveness of flood polders is subject to considerable uncertainty, e.g., concerning return periods of flood events as well as future development of assets, population density and interest rates.

We present a conceptual workflow for CBA of the flood polder program. Its main focus lies on assessing the expected damages, as the reduction thereof is the flood polders’ primary benefit. For this purpose, we perform a comprehensive risk analysis, which involves combining different models for hazard, exposure and vulnerability. The process of hazard analysis is particularly demanding as it includes a catalogue of deterministic flood events routed in a 1D-hydraulic model in combination with a probabilistic dike breach analysis. The large number of hazard areas resulting from different breach locations and characteristics are investigated by means of GIS analysis.

In addition, we highlight the importance of performing sensitivity and uncertainty analysis as part of the evaluation process. This is crucial to address the challenges related to the inherent uncertainties in the occurrence of overload events and future developments as well as model choices, e.g., with regard to model resolution and data sources. We show that the effects of uncertainty on the economic efficiency criterion should be communicated to the decision-makers in order to facilitate robust decisions.
Mapping human impacts to support sustainable uses of marine ecosystems in the Mediterranean sea
Authors: Melaku Canu Donata , Zunino Serena , Bendoni Michele , Brandini Carlo , Čermelj Branko , Drago Aldo , Faure Vincent , Galea Antony , Galiana Savitri , Garcia Xavier , Grenz Christian , Lapucci Chiara , Ličer Matiaz , Lipizer Marina , Mavrič Borut , Perna Massimo , Previati Monica , Queirós Lucia , Ruitton Sandrine , Viure Laia
Published: March 2022

Local and global anthropogenic pressures due to climate change and to local uses and activities are exerting significant cumulative impacts to greater extents of the oceans and seas. Coastal ecosystems are particularly threatened by the intensity and coexistence of several marine uses and pressures, including sewage and urban constructions, tourism, ship traffic, fisheries and aquaculture. Assessment of pressures and the identification of mitigation measures are key urgent actions, as already highlighted by the EU Marine Strategy Framework Directive and the United Nations Sustainable Development Goal 14. The aim of this work, developed within the Interreg-Med project SHAREMED, is to systematize existing knowledge on threats and pollution, including those of transboundary origin, for long term strategies and common action marine spatial planning, jointly developed with stakeholders. The quest is to assess coexisting environmental threats, and their propagation in space and time, at proper spatial and temporal scales, according to the type and action of each stressor (i.e. global vs. local). Cumulative pressures are tackled within a dedicated Atlas comprising three sub-basinsins of the Mediterranean Sea: the North Adriatic Sea, the Sicilian Channel and the North-Western region. The Atlas integrates information generated at the best available resolutions by 1) in-situ sampling, 2) remote observations, 3) numerical models, and 4) focusing on target ecosystems and habitat forming species. These sub-basins are subjected to multiple local and larger scale (e.g. climate) pressures that propagate in space and time, and across political boundaries, that need to be addressed through coordinated actions, based on evidence-rooted common understanding. Interactions with relevant Stakeholders, solicited through an online survey, and meetings, were used to select target ecosystems and to identify the key relevant pressures. The Atlas is based on open-access databases and portals, literature reviews and from ad-hoc model simulations concerning marine heatwaves, ship traffic, oil pollution, marine litter and fishing efforts. We will present the main preliminary results and needs and gaps in observations related to marine ecosystems threats.
Effects of asperities and roughness on frictional slip of laboratory faults
Authors: Guerin-Marthe simon , Dresen Georg , Kwiatek Gzegorz , Wang Lei , Bonnelye Audrey , Martinez-Garzon Patricia
Published: March 2022

Natural faults are heterogeneous features, with complex geometries and material properties. Understanding how the geometrical complexities of a fault affects the dynamics and preparatory phase of earthquakes is of crucial importance for seismic hazard assessment. In laboratory samples, frictional sliding along prefabricated faults may produce so called stick-slips comparable to dynamic ruptures observed during earthquakes. While the effect of roughness has been shown to influence significantly the frictional behavior of laboratory faults, there are only a few studies investigating more complex types of fault heterogeneities. In this study, we conduct friction experiments on granite with inclined sawcut faults, under a constant confining pressure of 35MPa. Samples are loaded using an axial displacement rate of 0.5 µm/s.  At  similar boundary conditions we compare the slip behavior of (1) a smooth fault, (2) a smooth fault with a single asperity, a 7 mm diameter vertical pin traversing the contact interface, and (3) a rough fault prepared by sandblasting the surface with silicon carbide. A key result of this study is that slip behavior depends on fault roughness and is influenced in a non-trivial way by asperities. The smooth fault displays unstable stick-slip as opposed to the rough fault showing predominantly creep. The smooth fault with the pin exhibits a slip behavior in-between, with very regular stress oscillations that seem to be attenuated by the presence of the pin (asperity). Only after failure of the pin, we observe the stress drop during instabilities to increase regularly with cumulative slip. We also show that in the case of a fault with a single asperity, the slip velocity is less than an order of magnitude lower compared to a similar smooth fault without this asperity.
Downscaled hyper-resolution (400 m) gridded datasets of daily precipitation and temperature (2008–2019) for East Taylor subbasin (western United States)
Authors: Mital Utkarsh , Dwivedi Dipankar , Brown James B. , Steefel Carl I.
Published: March 2022

Abstract. High resolution gridded datasets of meteorological variables are needed in order to resolve fine-scale hydrological gradients in complex mountainous terrain. Across the United States, the highest available spatial resolution of gridded datasets of daily meteorological records is approximately 800 m. This work presents gridded datasets of daily precipitation and mean temperature for the East-Taylor subbasin (in western United States) covering a 12-year period (2008–2019) at a high spatial resolution (400 m). The datasets are generated using a downscaling framework that uses data-driven models to learn relationships between climate variables and topography. We observe that downscaled datasets of precipitation and mean temperature exhibit smoother spatial gradients compared to their coarser counterparts. Additionally, we also observe that when downscaled datasets are reaggregated to the original resolution (800 m), the mean residual error is almost zero, ensuring spatial consistency with the original data. Furthermore, the downscaled datasets are observed to be linearly related to elevation, which is consistent with the methodology underlying the original 800 m product. Finally, we validate the spatial patterns exhibited by downscaled datasets via an example use case that models lidar-derived estimates of snowpack. The presented dataset constitutes a valuable resource to resolve fine-sale hydrological gradients in the mountainous terrain of the East-Taylor subbasin, which is an important study area in the context of water security for southwestern United States and Mexico. The dataset is publicly available at https://doi.org/10.15485/1822259 (Mital et al., 2021).
Mineral surface area in deep weathering profiles reveals the interrelationship of iron oxidation and silicate weathering
Authors: Fisher Beth A. , Yoo Kyungsoo , Aufdenkampe Anthony K. , Nater Edward A. , Feinberg Joshua M. , Nyquist Jonathan E.
Published: March 2022

Abstract. Mineral specific surface area (SSA) is generated as primary minerals weather and restructure into secondary phyllosilicate, oxide, and oxyhydroxide minerals. SSA is a measurable property that captures cumulative effects of many physical and chemical weathering processes in a single measurement and has meaningful implications to many soil processes, including water holding capacity and nutrient availability. Here we report our measurements of SSA and mineralogy of two 21-meter deep SSA profiles at two landscape positions, in which the emergence of a very small mass percent (0.8–2.7 %) of secondary oxide generated 36–81 % of the total SSA at both landscape positions. The SSA transition occurred at 3 meters and did not coincide with the morphological boundaries of soil to weathered rock or with the water table. The 3-meter boundaries coincide with the depth extent of secondary iron minerals and secondary phyllosilicates. Although elemental depletions in both profiles extend to 7 and 10 meters, secondary minerals were not detected below 3 meters. The 3-meter depth marks the emergence of secondary oxide minerals, and this boundary appears to be the depth extent of oxidation weathering reactions. Our results suggest that oxidation weathering reactions may be the primary limitation in the co-evolution of both secondary silicate and secondary oxide minerals.