bluuebunny/crossref_metadata_2025 huggingface dataset:
Forecasting Forest Fires in South Korea Using a Diagnostic Forest Fire Model
Authors: Roh Minwoo , Lee Sujong , Lee Woo-kyun
Published: March 2024

Forest fires exert a significant impact on Earth's ecological systems, resulting in consequences such as deforestation, habitat degradation, and adverse effects on environmental, economic, and social domains. The restoration of areas affected by forest fires demands substantial time and effort to return them to their original state. Proactive identification of areas prone to forest fires is crucial for minimizing the damage caused by such incidents. In this study, a forest fire diagnostic model was developed to enhance the precision of forest fire risk predictions. The model utilized remote sensing data and human activity maps. To gauge the dryness of the land surface, the Vegetation Temperature Condition Index (VTCI) was employed, and density maps of roads, buildings, and cropland were incorporated for the human activity maps. The algorithm of the model was based on the Random Forest classifier, and it was trained on forest fire occurrence data from 2016 to 2020 across South Korea. To assess the actual performance of forest fire forecasting, short-term forecasts for a 3-day period were conducted from February to May 2023. The model successfully predicted 80% of forest fires during this evaluation period.
Source apportionment of methane using δ13C and δ2H 
Authors: Fisher Rebecca , Woolley Maisch Ceres , Lowry Dave , France James , Fernandez Julianne , Warwick Nicola , Nisbet Euan
Published: March 2024

Use of both δ13C and δ2H measurements can be used to constrain methane sources. δ13C isotopes have been used to help identify the reasons for the continued growth in atmospheric methane, which since 2007 has coincided with a decline in δ13C. δ2H could offer a third dimension to help constrain the global methane budget, but its use has been limited because less data are available. There is a need for better identification of δ2H isotopic source signatures, and more long-term atmospheric data records.We present results of field campaigns carried out in a variety of source regions to characterise isotopic signatures and consider complexities in constraining source signatures for some categories. We also consider use of methane isotopic measurements at different scales for source partitioning.The isotopic signatures of urban emissions of methane have been characterised in London, Bucharest and Ho Chi Minh City. Methane sources in these cities are very different, with emissions being mostly from gas leaks in London, from wastewater and gas leaks in Bucharest, and from waste and traffic in Ho Chi Minh City.Measurements of cattle methane emissions in Jersey and Kenya show different isotopic signatures in methane from manure and eructation. Cattle diet, the age of manure and waste management practices cause variability in the isotopic signature of emitted methane.Wetland methane emissions from sites across Finland and Canada were collected in summer 2022. The Finnish boreal wetland methane isotopic signatures were δ2H -326 ± 19 ‰ and δ13C -68 ± 4 ‰, comparable with the results from Canada. Both δ2H and δ13C  in methane from boreal wetlands tends to be more depleted in the heavier isotope than in tropical wetland methane emissions.Both δ13C and δ2H can be used in the UM-UKCA chemistry climate model which includes multiple methane tracers tagged by isotopic composition and source type. It is hoped that better characterisation of the regional variability in isotopic signatures of some sources will help improve the ability to model the global methane budget.
Global distribution and drivers of microbial carbon use efficiency for projecting soil organic carbon fates under a changing climate: A meta-analysis
Authors: Bi Qing-Fang , Ahrens Bernhard , Wutzler Thomas , Reichstein Markus , Schrumpf Marion
Published: March 2024

Comprehending the factors influencing microbial carbon use efficiency (CUE), and where CUE is most optimal to soil organic carbon (SOC) storage, are crucial for managing microbial roles in SOC sequestration and model prediction. Yet, establishing a direct mathematical relationship between CUE and SOC might be challenging, with global distributions and controls remaining unresolved, particularly in response to various global changes. Here, we leverage a global synthesis of CUE measurements by 18O-microbial DNA growth, and observed an average CUE across all biomes at 0.3, with the highest in temperate grasslands and deeper soils, and the lowest in tropical forests. Random forest analysis identified climates (aridity index and mean annual temperature: MAT) and soil properties (pH, bulk density and soil C:N ratio) as primary drivers influencing CUE. However, microbial biomass size overall exhibited a smaller effects on CUE, despite its substantial impact in each land use type. We then review how these drivers affecting CUE values may be altered by warming, soil fertilization, altered precipitation and elevated carbon dioxide. Notably, nitrogen additions plays a big role in increasing CUE and promoting SOC contents, while warming effects depend on time-scale, with long-term warming potentially leading to SOC losses with a lower CUE and growth. Moreover, we found that the CUE–SOC relationship varies across different climates, greatly driven by MAT and soil properties. Higher CUE promots SOC per fine fraction (clay+silt) across the major data points, contrasting with a negative relationship in a subarctic study, where pH is the primary determinate. Consequently, there might be no simple linear relationship between CUE and C in microbial biomass and soil. We conclude by discussing the integration of CUE into SOC models and the necessity of incorporating interactions between CUE and individual drivers for predicting soil carbon-climate change scenarios. Our study underscores the importance of considering microbial CUE and other microbial processes for improving projections of SOC dynamics.
How important are hydrogen imports for European carbon neutrality?
Authors: van Greevenbroek Koen , Schmidt Johannes , Zeyringer Marianne
Published: March 2024

Hydrogen could play a crucial role in Europe's transition to carbon neutrality by 2050. However, the size and scope of the upcoming hydrogen sector is subject to great uncertainty due to unknown future costs, technological developments and competition with other energy carriers. The prospects of hydrogen imports from outside the EU is possibly subject to even greater uncertainty. Are hydrogen imports needed at all? Are they an essential element of the green transition? In the present work we use a multi-horizon energy system optimisation framework to investigate the rationale for EU hydrogen imports. In particular, we analyse when hydrogen imports may alleviate the most critical bottlenecks in achieving net carbon neutrality by 2050. The main bottlenecks of interest are rapid growth in renewable energy and hydrogen production. To ensure robustness of the results, we use near-optimal methods to map out a large variety of transition pathways under a number of different political and technological scenarios. The pathways are evaluated on cost and land-use impact inside Europe as well as potential upstream impacts of imported hydrogen. Using this holistic approach allows us to uncover when hydrogen imports are compelling and when they are dubious. 
Elementary mathematics sheds light on the transpiration budget
Authors: D'Amato Concetta , Rigon Riccardo
Published: March 2024

This contribution aims to present a concise and effective methodology for accurately characterizing transpiration, a crucial component of the hydrological cycle. Rather than delving into intricate derivations of transpiration formulas, we employ simplifications, such as a century-old turbulence model, principles from Lord Kelvin's thermodynamics, and an energy budget overlooking thermal leaf capacity. Despite these simplifications, we assert the general validity of our approach in identifying primary mechanisms underlying transpiration.Our methodology initiates with a treatment of five equations, including the mass budget, outlining the procedure: Clausius-Clapeyron equation, water vapor transport, turbulence-induced thermal energy transport, and stationary energy budget with radiative feedback. Initially, we introduce a simplified approach excluding the water budget, followed by its inclusion to demonstrate that adhering to the water budget is sufficient without imposing artificial constraints. Utilizing a linearized form of the Clausius-Clapeyron equation, we establish the Penman Formula, a well-regarded solution for estimating temperature (T), air vapor content (e), and thermal heat transport (H). Through water mass balance, we reveal that leaf pressure potential is dynamically influenced by atmospheric evaporation demand and soil moisture content, challenging the notion of capillarity as the sole determinant. Building on Schymanski and Or's (2017) research, we extend it by explicitly incorporating the canopy. Even within the "big leaf" approach (Bonan et al., 2021), we introduce a dependency on leaf area index (Lc) in formulas to accurately consider the canopy's impact. Additionally, we provide a detailed treatment of radiation, accounting for the canopy's influence, following Ryu et al. (2011) and de Pury (1995) methodologies.In the realm of canopy analysis, our contribution reveals discrepancies compared to common simplistic approaches, shedding light on unique aspects of the subject matter.
Architectural Strategies for Flood Mitigation in Urban Environments: A Study of Traditional Elements and Contemporary Resilience
Authors: Naghedi Seyedeh Negar , Maleki Ali , Vahid Rasool , Piadeh Farzad , Behzadian Kourosh
Published: March 2024

Natural disasters cause extensive losses worldwide annually. Flood events are responsible for economic and life-threatening damages[1]. To mitigate flood risks and resulting damages, particularly in the construction of residential buildings, two approaches exist. First: constructing in areas with lower flood susceptibility, and second: implementing architectural solutions to fortify structures against floods and associated hazards. Due to the presence of water resources, rivers, etc., prompting urban expansion due to reasons like transportation, trade, agricultural use, household consumption, etc., construction near rivers and flood-prone areas becomes inevitable[2]. This underscores the importance of the second approach—architectural fortification.In this study, areas highly susceptible to flooding were identified from flood zoning maps using artificial intelligence to adapt these maps and estimate the most hazardous regions[3]. Subsequently, by examining the specific elements of traditional architecture in each of these areas and exploring the cause and function of each element in facing floods over time, attention is given to the particular and regional (indigenous) architectural features that have responded to floods. Finally, appropriate architectural measures and responses to reduce flood risks, such as constructing at elevation or suitable gradients, is combined with early warning systems to provide a proper route for the future construction projects.Keywords: Flood forecasting; Flood prone areas; Architectural fortification[1] Naghedi, S.R., Huang, X. and Gheibi, M., 2023. A smart dashboard for forecasting disaster casualties: An investigation from sustainable development dimensions (No. EGU23-17237). Copernicus Meetings.[2] Yan, J., Naghedi, R., Huang, X., Wang, S., Lu, J. and Xu, Y., 2023. Evaluating simulated visible greenness in urban landscapes: An examination of a midsize US city. Urban Forestry & Urban Greening, 87, p.128060.[3] Vahid, R., Farnood Ahmadi, F., & Mohammadi, N. (2021). Earthquake damage modeling using cellular automata and fuzzy rule-based models. Arabian Journal of Geosciences, 14, 1-14.
IPSL climactions and the bottom-up ecological transformation of  a climate research institute (2016-2024)
Authors: Bonnefoy Lea ,   IPSL Climactions
Published: March 2024

For several decades now, research communities working on the climate, its changes, including current global warming, and its consequences have been recommending drastic reductions in human-made greenhouse gas emissions and, more generally, in the ecological footprint of human activities. This implies the implementation over the next 10 to 20 years of profound and rapid systemic transformations. The latest IPCC reports show that such transformations are only possible if they involve all parts/sectors of society. Given the existence of a range of ecological constraints and the foreseeable limits to scientific and technical advances, the transformations to be implemented must also include a strong component of sufficiency ("avoidance”).Since 2016, IPSL scientists and support staff have been working together along these lines to transform the institute's professional practices.  This engagement is generally seen as : (i) a necessity: to initiate a transition in its research practices that will bring its professional behavior in line with the message of climate urgency that it has been diffusing for over 30 years; (ii) an opportunity: to accelerate the transition at a societal level by opening up new channels of exchange with society, encouraging collective action by example, and reinforcing the credibility of its warning message; (iii) a safeguard: collective bottom-up thinking at laboratory level to ensure that this transition takes place with maximum respect for our research practices and our well-being at work, and is not imposed by potentially inappropriate top-down measures.Achievements include (i) the development of methodologies for calculating the carbon footprint generated by staff activities and professional practices, (ii) concrete contributions to the reduction of the environmental footprint of professional travels, digital and high performance computing activities, purchases and finally observation of the earth. We will present here our approach, methodologies, achievements, and reflections at this stage, with the hope to stimulate exchange with other ongoing or emerging initiatives in other parts of the world.  
Stochasticity of natural processes concerning loads exerted on offshore wind turbines
Authors: Vrettou Sofia Efraimia , Iliopoulou Theano , Koutsoyiannis Demetris
Published: March 2024

Sofia Vrettou; Theano Iliopoulou, and Demetris KoutsoyiannisThe tendency to avoid non-renewable sources in electricity production has led –among other alternative models of energy production- to the rapid growth of offshore wind farms. With regard to the structural design of the offshore wind turbines, international standards for the design of the turbines, suggest that the forces executed on the turbine’s pile, primarily induced by wind and waves, should be calculated by using dynamic models and short-term simulations of the natural parameters. However, due to the stochastic nature of wind and wave generated forces, such dynamic procedures and the short-term approach fail to accurately calculate or either - in the desired scenario - predict the exerted loads. On the other hand, stochastic methods do take into account characteristics of natural processes such as long-term persistence that are crucial in designing the turbines. In this work we aim to estimate the uncertainty in exerted forces using Hurst-Kolmogorov stochastic models and compare the results with those calculated using deterministic methods. A key objective is to examine how the fatigue of the structures is affected by the stochasticity of natural processes.
A flexible modelling framework for model creation based on perceptual understanding in integrated human-water systems
Authors: Maes-Prior Robin , Dobson Barnaby , Mijic Ana
Published: March 2024

Perceptual and conceptual modelling has been used historically by hydrologists to develop models rooted in a physical reality. As human activity increases and intertwines with the natural world, hydrological systems cannot be treated in isolation, particularly in urbanised areas. We argue that expanding our models and modelling approaches to consider interactions with water infrastructure can help us to identify the dominant processes and interactions within coupled human-water systems (CHWS) and guide our modelling processes towards models that produce results for the right reasons. We develop a three-level perceptual modelling approach that maps CHWS complexity in a systemic way. Perceptual models are representations of a system of interest based on stakeholder’s understandings and rooted in reality (e.g. visualised as a cross-section of the system with processes mapped on). Conceptual models are representations that break down the perceptual model to a component and state level (e.g. visualised as buckets and flows). From these definitions the framework was created to construct a computational model from an initial understanding of the region of interest. This framework prioritises engagement of different stakeholders at key junctions in the model making process, as well as providing a clear roadmap of modelling decisions. We applied this modelling approach for the Mogden Wastewater Catchment in North West London. The Mogden case study captures the interaction between surface water, groundwater and the sewer network, giving insight into the understudied field of sewer infiltration/exfiltration, highlighting the framework’s ability to better understand impact and behaviour of complicated flow paths. The case study highlights how this framework allows for the identification of interactions between human activity and the urban water system, producing models which are rooted in reality. The case study further revealed the benefit of flexible models, such as the implemented WSIMOD, for this framework, capturing diverse system perceptions and adaptability to include dominant processes.
Multi-scale anisotropy development in viscous flow due to fabric evolution: Numerical modelling, upscaling, and application for strain localization
Authors: Halter William R. , Kulakov Roman , Duretz Thibault , Schmalholz Stefan M.
Published: March 2024

Viscous flow controls large parts of tectonic deformation. Viscous strain localization and associated softening mechanisms are important for subduction initiation and the generation of tectonic nappes. However, viscous flow of geologic materials can have a complex behaviour due to their evolving microstructure, such as an evolving anisotropy due to fabric development or a crystallographic preferred orientation, or due to other evolving microstructure, like, e.g., grain size or dynamic recrystallization.In this contribution, we focus on strain localization in viscous rock due to the generation of anisotropy resulting from fabric evolution. Particularly, we focus on multi-scale anisotropy evolution in shear zones with many strong or weak inclusions, representing for example porphyroclasts. The shape change and relative alignment of the inclusions during shearing generates an anisotropy on the scale of the inclusions, termed here macroscale. We spatially resolve this macroscale anisotropy in the numerical simulations. Additionally, we consider the evolution of a microscale anisotropy in the shear zone matrix, representing the formation of a mylonitic foliation. We do not spatially resolve this microscale anisotropy but model it with an anisotropic flow law that involves different normal and tangential viscosities. We calculate the finite strain ellipse during shearing and use its aspect ratio as proxy for the anisotropy that governs the ratio of normal to tangential viscosity. To track the orientation of the anisotropy during deformation we apply a director method.We perform numerical simulations with the two-dimensional state-of-the-art thermo-mechanical code MDoodz (Duretz et al. 2021). We evaluate the impact of micro- and macroscale anisotropy on strain softening and localization in shear zone up to shear strains in the order of ten. We further discuss the quantification of effective anisotropies that can be used for upscaling, for example for lithospheric scale numerical models. Moreover, we compare the numerical results to the analytical solution and the numerical results of Dabrowski et al. (2012). A particular feature of some simulations is the formation of buckle folds in regions with highly stretched weak inclusions. Bibliography Duretz T., R. de Borst and P. Yamato (2021), Modeling Lithospheric Deformation Using a Compressible Visco-Elasto-Viscoplastic Rheology and the Effective Viscosity Approach, Geochemistry, Geophysics, Geosystems, Vol. 22 (8), e2021GC009675Dabrowski, M., D. W. Schmid, and Y. Y. Podladchikov (2012), A two-phase composite in simple shear: Effective mechanical anisotropy development and localization potential, J. Geophys. Res., 117, B08406, doi:10.1029/2012JB009183
Non-uniqueness in sediment transport in river network hydrology-sediment modelling
Authors: Molnar Peter , Meierhans Sascha , Battista Giulia , Hirschberg Jacob , Droujko Jessica , Sinclair Scott
Published: March 2024

Sediment cascades are a convenient way of conceptualizing the transfer of sediment from hillslope production areas, through the river network, to the river basin outlet. Distributed hydrology-sediment models play an important role in the prediction of these source-to-sink links, because they can explicitly connect water and sediment fluxes along topographically-driven pathways. Here, we provide some examples of such cascade-based hydrology-sediment model applications in alpine environments and some problems related to their use.In particular, we highlight two critical problems with hydrology-sediment modelling that go beyond trivial model calibration difficulties. These address fundamental issues of (a) non-uniqueness in sediment source mixing, and (b) sediment supply limitations. The first problem of non-uniqueness is known in hydrological modelling as the curse when models perform well at basin outlets for the wrong reasons, misrepresenting hydrological processes within the basin. In geomorphology, this concept has not received the same level of attention. Here we show that even a calibrated physically-distributed hydrology-sediment model can be subject to non-uniqueness, and provide the same suspended sediment yields at the basin outlet with completely different combinations of sediment sources. Including sediment tracers in model validation helps to identify this problem, and it is also helpful to check simulations at sub-basin scales where we are closer to distinct sediment sources. The second problem of sediment supply limitations is a challenge for all models that rely on transport capacity formulas for sediment transport. In our experience, both supply and transport capacity limit sediment transport at the basin scale, and we need to include this in our models. For example, we show that supply limitations can completely change the seasonality of sediment yields and render many climate change impact studies worthless.Finally, we argue that both problems above, at least for suspended load, can be partially addressed by novel monitoring. For example by low cost smart sensors that allow a distributed sensing of sediment fluxes above and below potential sediment sources at high resolutions, or by high resolution remote sensing to capture space-time variability in river turbidity. This kind of data can dramatically improve our ability to calibrate models, reduce non-uniqueness, and over the long term identify the key signatures of sediment supply in river systems. It is our opinion that improving the predictions of climate and environmental change effects on sediment yields requires both better model validation as well as new data.
Effect of soil texture on root water uptake  
Authors: Mhimdi Imen , van Dusschoten Dagmar , Javaux Mathieu
Published: March 2024

Effect of soil texture on root water uptake 
I.Mhimdi, D.van Dusschoten, M.Javaux
Forschungszentrum Jülich, Institute for Plant Sciences (IBG-2 ),  Jülich, Germany
Catholic University of Louvain, Earth and Life Institute, Louvain La Neuve, Belgium
Understanding how root water uptake (RWU) depends on soil properties is a key to estimate plant transpiration dynamics and its response to climate. Despite the fact that soil texture plays an important role in determining plant water availability and mechanical resistance, texture and RWU have not often been considered simultaneously in literature. Recently, a novel method was developed by (van Dusschoten et al, 2020), the SWaP (Soil Water Profiler), in which soil water content and its depletion could be monitored during a modulated light regime in order to derive the RWU profile. The scope of our work is to investigate with the SWaP how soil texture impacts RWU dynamics. We hypothesize that the soil texture will impact the distribution of the rhizosphere resistance in the rhizosphere and thereby its RWU.
Eight faba bean (Vicia Faba) plants were grown in 45cm PVC pots, two soil textures (Loamy and Sandy) with different dry density were used. The plants were subjected to progressive water deficits, and were measured continuously with the SWaP, while applying light modulations during daytime to measure instantaneous 1D water content and derived root water uptake profiles. In combination with the SWaP, several MRI measurements were performed combined with image analysis, in order to determine the local root length distribution and its relation to RWU.For loamy soil, MRI measurements showed a structured spiral shape, an extensive and deeper root system with higher root diameter. Roots were less smooth, tortuous and with denser lateral roots in sandy soil. In both textures, root water uptake decreased with depth, which can be explained by the less abundant roots in lower soil layers and a higher resistance for the deeper roots (Müllers et al, 2023). Root water uptake profiles and total water uptake dynamics were different, between soil types, which could partially be attributed to differences in root distribution.
References
van Dusschoten et al., 2020, Spatially resolved root water uptake determination using a precise soil water sensor, Plant Phys.
Müllers et al., 2023, Deep-water uptake under drought improved due to locally increased root conductivity in maize, but not in faba bean, Plant, Cell & Environment.
Could earthquakes cause rapid dehydration of serpentinite?
Authors: Tajčmanová Lucie , Cionoiu Sebastian , Schuppenhauer Dan
Published: March 2024

Dehydration reactions can influence the occurrence of earthquakes at a range of depths, highlighting the importance of understanding these reactions in the study of seismic activity. We have performed several pilot experiments that included the construction of a controllable fast pressure drop unit attached to the piston-cylinder apparatus. This setup makes it possible to simulate conditions that represent a fast pressure drop during an earthquake event. We focused on serpentinite dehydration because 1/ it plays an important link between the deep geodynamic processes occurring in subduction zones and the seismic and volcanic activity and 2/ the interplay between serpentinite dehydration and deformation during the earthquake cycle is not yet fully understood. To test the experimental setting, we first performed a series of static experiments under the conditions that are already in the olivine stability field. After the static experiments at high pressure (1.1 GPa), we performed the controlled fast pressure drop experiments to 0.3 GPa as well as the ramping experiments, in which a series of pressure build-ups and drops were performed maintaining the high temperatures (570 to 640 °C) to simulate the earthquake cycle. In these experiments, olivine was an order of magnitude more abundant than in the one-hour low-pressure static experiment. The pressure drop occurs in seconds. The ramping experiment lasted only 10 mins before cooling down. The results may challenge conventional wisdom about the timescales of mineral reactions under extreme conditions, such as during earthquakes.
Impact of future climate on Caithness and Sutherland peatlands
Authors: Teleti Praveen Rao , Andersen Roxane , Bischoff Mascha , Marshall Chris
Published: March 2024

High-latitude boreal peatlands store up to a third of all the terrestrial carbon as peat, partially as decomposed organic matter. And, they act as reservoirs of vast amounts of GHG (Greenhouse gases) such as methane. The balance between being a source, or a sink of GHGs depends on continuation of favourable conditions under which peat is accumulated, or at least maintained through a series of complex feedback mechanisms linking mechanics, ecology and hydrology. Several peatland ecosystems have been disturbed in the past due to land-use change, build-up of roads and other infrastructure, and changing water flow in and out of peatlands. While these disturbances have significantly changed characteristics of many peatlands, they have affected a relatively small area of global peatlands. However, projected climate changes in the future threaten the balance of all global peatland ecosystems. Total rainfall and mean temperature are known to play a significant role in sustaining and expanding blanket bogs – a globally rare type of peatland confined to high latitude regions with year-round cool climate. However, the number of rain days, and length and severity of drought conditions are also important for peatland health. Here, we present projected land use changes and GHG emissions under various RCP climate scenarios along with seasonal weather changes on blanket bogs in Caithness and Sutherland regions of Scotland. Our results show that high precipitation-low temperature climatic regimes necessary for maintaining and restoring peatlands may be changing with the highest contribution from changing rainfall patterns. We highlight how this could impact resilience mechanisms across a range of scales. 
Remotely sensed rivers to account for geomorphic processes in river basins threatened by anthropic pressures and climate changes
Authors: Bizzi Simone
Published: March 2024

Remote sensing since a few years are offering unprecedented opportunities to monitor the environment and its functioning. Fluvial geomorphology is affected by these advances. Nowadays we can address basin analysis of river geomorphic trajectories and simulate sediment connectivity and transport at the network scale thanks to available remotely sensed geomorphic datasets. However, these assessments and simulations present distinct limitations and must be integrated with field data and high-resolution datasets acquired in selected locations for validation purposes. Despite that, if properly managed the current ability to generate an understanding of river geomorphic functioning and sediment connectivity at the network scale is notable and can support modern river management in assessing scenarios of future strategic decisions such as, water resources issues, rehabilitation objectives and flood protection schemes.  In this talk I will present two case studies where we have been applying such approaches. The first concerns the Mekong river, one of the largest and most threatened river system globally, and its strategic dam planning for the following 30-50 years. We have assessed sediment connectivity and transport for different scenarios of dam planning and estimate the risk of sediment starvation for the Mekong Delta at risk of drowning identifying more sustainable and less impacting dam locations compared to the existing ones.  The second case is the Vjosa river, one of the last unpaired braided system in Europe, recently threatened by the possibility to build multiple dams along its course to produce hydroelectric energy. Here we have developed simulations able to link changes in sediment transport due to dam building with likely adjstments in river patterns and morphology with multiple consequences in terms of river equilibrium and ecosystem services provided. Finally, current capacity to understand river geomorphic functioning at the network scale will be discussed. Impacts of strategic management measures and climate changes can nowadays be predicted in terms of sediment transport and river geomorphic adjustment processes likely occurring in the coming years. Rarely modern management uses the full capacity of this discipline to address management decisions, and this lack of exploitation of available knowledge is a responsibility we need to correct as a community in the future.  
The Neogene record of Himalayan erosion in the Bengal Fan
Authors: France-Lanord Christian , Galy Albert , Galy Valier , Huyghe Pascale , Lavé Jérôme , Lenard Sébastien , Limonta Mara , Rigaudier Thomas , Spiess Volkhard , Tachambalath Aswin
Published: March 2024

Over the Tertiary, the uplift of the Himalaya combined to the development of the monsoon generated the largest erosion basins of the planet. More than 80% of the erosion is exported to the Bay of Bengal by the Ganga-Brahmaputra river system and generates turbidity currents which convey detrital sediment building the Bengal Fan. In the modern Himalaya, the monsoon rainfall and tectonic processes shape the erosion pattern. The monsoon seasonal precipitation ensures efficient transport of sand-rich sediments in the basin despite long distances through a very flat floodplain and delta. Rapid transport also acts as a limiting factor for weathering as it reduces residence time in the floodplain but favors efficient carbon burial. The IODP Expedition 354 drilled the Bengal Fan with seven sites over a 320 km E-W transect at 8°N. This construcs a composite sedimentary record of Himalayan erosion over the Neogene and Quaternary. Sediments are predominantly composed of turbidites generated from the Ganga-Brahmaputra delta. Turbiditic sediments show mineralogical, geochemical and isotopic characteristics which reveal a close analogy with those of the modern Ganga-Brahmaputra river. Sand deposition is dominant and is present in several meters thick sand lobe as well as in levee turbidite (Bergmann et al. 2020). Sand was used to determine average erosion rates of the Himalaya using quartz in situ concentrations of cosmogenic 10Be. Those show stable rate in spite of the onset of a more unstable climate from the Pliocene to the Pleistocene (Lenard et al. 2020). Major element concentrations and Sr-Nd isotopic compositions of turbidite samples reflect combined effects of geological sources exposed to erosion, weathering and mineral sorting during transport. Deciphering these controls, based on the comparison between turbidite samples and modern river sediments of the Ganga and Brahmaputra basin reveals evolution from Miocene to present. Changes appear in the abundance of detrital carbonates likely reflecting decreasing exposition of the Tethys Himalaya to erosion since Miocene. Clear increase in the silicate Na and Ca concentrations from Miocene to Pleistocene indicates major change in the weathering conditions in the basin which can be related to longer residence time of the sediment in the floodplain and lower erosion ratesin the Miocene.Bergmann et al. 2020, G. cube 10.1029/2019gc008702Lenard et al. Nat Geosc. 2020, doi:10.1038/s41561-020-0585-2
The importance of bed roughness on ice sheet flow investigated using a full-Stokes ice flow model
Authors: Swift Darrel , Martin Carlos , Ely Jeremy
Published: March 2024

We present detailed modelling of ice flow over a synthetic topography using the full-Stokes ice flow model ELMER-ICE. Our results indicate that landforms/obstacles under 1000 m wavelength contribute importantly to basal drag, implying that predictive ice sheet models that are initialised using static parameterisations of basal drag will greatly underestimate the possible mediating effects of bedrock topography. We conducted numerous simulations using a 10 m resolution, 40 x 22 km model domain with a uniform ice thickness of 1000 m and with sliding restricted to a 20 km-wide central corridor to negate ice leaving the lateral margins. Basal slipperiness (i.e. skin drag) in all simulations used the value obtained during an initial simulation using an entirely flat bed and an imposed surface velocity of 150 m a-1. Subsequent simulations used a synthetic bed with wavelength 5 km, amplitude 200 m, and randomised superimposed smaller-scale roughness. Because ice sheet beds are bumpy at a range of scales - from landforms reflective of km-scale patterns of glacial bedrock erosion down to m-scale obstacles characteristic of bedrock structure – roughness was introduced gradually into the simulations by stepwise reduction of the degree of smoothing applied to the synthetic topography using a band-pass filter. Our results demonstrated that around two-thirds of observed surface velocity was by sliding, and that mean sliding velocity (and thus surface velocity) declined rapidly when introducing roughness with length scale smaller than 1000 m. Further, the observed decline appeared broadly exponential in relation to obstacle size as smaller roughness length scales were added, down to the smallest length scale (10 m) permitted by present model resolution. The results therefore highlight the potential importance of form drag provided by sub-km scale bed roughness in stabilising ice flow, including flow in grounding line locations that are critical to marine ice sheet stability. The results also have implications for predictive ice sheet models, which typically use static fields of basal drag derived from inversions of present-day surface observations, and do not distinguish between form and skin drag. As such, current models could imprecisely predict ice discharge and grounding line behaviour in regions of evolving bedrock or sedimentary landforms, which are ubiquitous to ice sheet beds.
Fast flood finite volume model for the shallow water equations using high-resolution bathymetry data 
Authors: Bitsch Max , Grooss Jesper , Sørensen Ole Rene , Engsig-Karup Allan
Published: March 2024

Fast and precise flood predictions are crucial in preventing disastrous outcomes associated with flooding. However, creating accurate flood predictions based on numerical models is extremely time-consuming, posing challenges for early warning systems. Consequently, less accurate models are often employed in practical applications due to the importance of simulation time. This is far from ideal as accuracy is key to get the predictions correct, jeopardizing the reliability of the predictions. The shallow water equations (SWEs), which are physics-based depth-integrated differential equations, are commonly used to accurately simulate floods on land. These models remain time-consuming for large-scale simulations, leading to the frequent use of coarse meshes in practical settings. Unfortunately, using coarse meshes presents difficulties in accurately representing bottom resistance, which is a non-linear function of water depth. Solving this problem traditionally requires overestimating the friction coefficients and a lot of practical experience.  

Advancements in the field of sub-grid resolution [1] and [2] have addressed this challenge by linking the source term and fluxes to the bathymetry at a sub-grid level. The sub-grid method involves dividing each cell into multiple sub-cells that store bathymetry data and roughness coefficients. This approach evaluates water depth and bottom resistances at the sub-cell level, resulting in a more precise representation at reduced computational cost. Additionally, this method accommodates flood and dry treatments by allowing cells to be partially wet, enabling them to adapt to the wet domain. 

At the session, we intend to introduce a new explicit finite volume scheme that leverages high-resolution bathymetry data to more accurately incorporate non-linear bottom resistance effects. Show preliminary results of how the conveyance is improved for large meshes and what that means for the total simulation time. This scheme is a step toward an explicit depth-dependent flood and dry method for the SWEs, enabling the use of coarse meshes while retaining critical physical effects. Ultimately, this innovation will drastically reduce simulation time for flood predictions, facilitating more accurate simulations within shorter durations.  

[1] V. Casulli. A high-resolution wetting and drying algorithm for free-surface hydrodynamics. International Journal for Numerical Methods in Fluids, 60:391–408, 2009. 

[2] N. D. Volp, B. C. Van Prooijen, and G. S. Stelling. A finite volume approach for shallow water flow accounting for high-resolution bathymetry and roughness data. Water Resources Research, 49:4126–4135, 2013. 
Modelling crop traits and fluxes under multiple abiotic stressors
Authors: Croft Holly , Caine Robert , Khan Muhammad
Published: March 2024

Agriculture is the largest consumer of freshwater, accounting for approximately 70% of the total global usage. As the human population continues to grow, demand for water will be exacerbated by a changing climate and shifting temperature and precipitation regimes. Dynamically modelling crop physiological function will be crucial to optimising crop management strategies. In this study we synergise hyperspectral and thermal remotely-sensed data to model plant traits and water fluxes in spring wheat (Triticum aestivum) in growth chambers within a controlled environment experiment under water and/or nitrogen stress conditions. Results showed that plants which had first received nitrogen fertiliser and were subsequently droughted presented the lowest water fluxes, and the lowest leaf chlorophyll content and photosynthetic capacity (Vcmax) values. Partial least squares regression (PLSR) analysis of hyperspectral reflectance data revealed key wavelengths sensitive to six different plant traits and fluxes (including relative water content, leaf nitrogen, stomatal conductance), with strong correlations between measured and modelled values (R2 = 0.84; p
Compound impact of extreme summer heat waves and droughts on surface urban heat island in Budapest
Authors: Dezső Zsuzsanna , Pongrácz Rita
Published: March 2024

The aim of our research is to investigate how heat waves affect the surface urban heat island (SUHI) phenomenon in Budapest, a mid-latitude city with significant year-to-year differences in temperature and precipitation. A unique, 22-year long time series of continuous measurements from the MODIS instrument on NASA's Terra and Aqua satellites was used to study the SUHI pattern, surface temperature and humidity in detail. The two decades of surface temperature data show a significant warming trend. Analysis of the summers shows that the SUHI intensity decreases as the rural area around the city becomes warmer, especially in July and August, as the less moisture available in the rural area is unable to reduce the surface temperature, similar to the urban area. Thus, the SUHI intensity is mainly determined by the rural surface temperature. During summers with frequent and intense heat waves and droughts, the SUHI is very weak because the land surface temperatures are very high in both urban and rural areas resulting in very little difference between the built-up area and the vegetation-covered surrounding. In our research, we analyse this phenomenon in detail for the years 2003, 2007 and 2022, when intense heat waves occurred in the region. Due to climate change, heat waves and droughts are projected to become more frequent, more intense and more persistent in the future, which is likely to result in adverse effects to the quality of life of urban populations. A detailed analysis aiming to understand the complex environmental processes in the urban environment is essential to develop effective adaptation strategies to the upcoming challenges of climate change.Acknowledgements: Research leading to this study has been supported by the Hungarian National Research, Development and Innovation Fund (under grant K-129162) and the National Multidisciplinary Laboratory for Climate Change (RRF-2.3.1-21-2022-00014).
Integrated reservoir and production system modeling of geothermal energy extraction at the Aquistore CCS site in Canada
Authors: Hau Kevin P. , Brehme Maren , Rangriz-Shokri Alireza , Malakooti Reza , Nickel Erik , Chalaturnyk Rick J. , Saar Martin O.
Published: March 2024

Mitigating the global climate crisis is the greatest challenge facing humanity thiscentury. The transition of current energy systems towards carbon-neutral energyis inevitable. Renewable energy sources, particularly those that are both baseload-and dispatch-capable, such as geothermal energy, are essential to replace currentenergy systems that emit large amounts of CO2. In addition, permanent isolationof CO2 from the atmosphere, using carbon capture and sequestration (CCS), isindispensable to limit global warming to 1.5°C.To enable the full potential of geothermal energy extraction and of CCS, theirefficiencies need to be improved. One possibility is to integrate both technologies.Using CO2 as the geothermal energy extraction fluid approximately doubles energygeneration rates, compared to conventional, brine-based geothermal systems underour base-case conditions. Such CO2 Plume Geothermal (CPG) systems reinjectthe produced CO2, eventually sequestering all CO2 underground. Extracting thegeothermal energy from the CCS reservoir results in additional CO2 storage poten-tial, as, for example, the CO2 density increases and the overall reservoir pressuredecreases. The CPG-generated heat, electricity, and/or revenue could “subsidise”CCS operations. Consequently, CPG could increase both the geothermal energyand the CCS capacities.Our CPG feasibility study combines an integrated production system modelingapproach with a history-matched reservoir model of an active CCS site (Aquistore,Canada). The integrated modeling approach is used to account for all relevantprocesses, from well-bore pressure and temperature drops to multi-phase, multi-component fluid flow in the reservoir to fluid separation, power generation, andcontinuous with reinjection of CO2 at the land surface, in a fully implicit matter.Our results suggest that stable CO2 circulation, extracting geothermal energybetween the underground CO2 plume in the saline reservoir and the land surface,is possible. Furthermore, we see additional CO2 storage potential, caused by thecirculation of CO2. Our simulations indicate that Aquistore may provide a uniqueopportunity for pioneering a CPG field test.
Machine Learning Approaches to Improve Accuracy in Extreme Seasonal Temperature Forecasts: A Multi-Model Assessment 
Authors: Mbuvha Rendani , Nikraftar Zahir
Published: March 2024

This study focuses on applying machine learning techniques to bias-correct the seasonal temperature forecasts provided by the Copernicus Climate Change Service (C3S) models. Specifically, we employ bias correction on forecasts from five major models: UK Meteorological Office (UKMO), Euro-Mediterranean Center on Climate Change (CMCC), Deutscher Wetterdienst (DWD), Environment and Climate Change Canada (ECCC), and Meteo-France. Our primary objective is to assess the performance of our bias correction model in comparison to the original forecast datasets. We utilise temperature-based indices recommended by the Expert Team on Climate Change Detection and Indices (ETCCDI) to evaluate the effectiveness of the bias-corrected seasonal forecasts. These indices served as valuable metrics to gauge the predictive capability of the models, especially in forecasting natural cascading hazards such as wildfires, droughts, and floods. The study involved an in-depth analysis of the bias-corrected forecasts, and the derived indices were crucial in understanding the models' ability to predict temperature-related extreme events. The results of this research contribute valuable information for decision-making and planning across various sectors, including disaster risk management and environmental protection. Through a comprehensive evaluation of machine learning-based bias correction techniques, we enhance the accuracy and applicability of seasonal temperature forecasts, thereby improving preparedness and resilience to climate-related challenges. 