Joint Research Centre Research Articles

LUCAS cover photos 2006–2018 over the EU: 874 646 spatially distributed geo-tagged close-up photos with land cover and plant species label

Abstract. In the European Union, since 2006, a tri-annual survey has sampled land cover and land use information under the Land Use/Cover Area frame Survey (LUCAS). A total of 1 351 293 observations from 651 780 unique locations for 106 variables were collected during the five LUCAS surveys, including a total of 5.4 million landscape photos representing the observer view in the four cardinal directions as well as point photos showing the actual surveyed point. In addition to these previously published photos, additional LUCAS cover photos were recorded, showing a close-up view and thus more detail of the sampled tree, crop and plant species. Between 2006 and 2018, 875 661 LUCAS cover close-up photos were collected, showing the relevant land cover and plant species on the entire photo with the absence of any other elements of the landscape in the frame. Photos containing potential privacy content were identified following a two-stage deep learning anonymisation process, resulting in the removal of 346 photos before publication. This paper summarises the collection of LUCAS cover photos and the filtering for mandatory privacy issues and also provides links to download the data along with the photo metadata and cross-links to the corresponding LUCAS-harmonised survey data. Moreover, after presenting the final public and open dataset consisting of 874 646 photos, potential applications relying on recent advances in geo-spatial analysis and statistical learning, such as large-scale biodiversity monitoring, are discussed. The data are available on the JRC Open Data Catalogue: http://data.europa.eu/89h/c83906d7-1817-495f-b4ba-f2e4b8859d48 (European Commission, Joint Research Centre, 2022).

EFFECT OF ULTRASOUND ON EXTRACTION OF HEAVY METALS FROM SEWAGE SLUDGE IN THE CONTEXT OF A POTENTIAL ECOLOGICAL RISK ASSESSMENT

The aim of the research was to investigate the effect of ultrasound waves on the recovery of heavy metals (HMs) from sewage sludge. For this purpose, we conducted a three-step sequential extraction process proposed by the Community Bureau of Reference (BCR; presently the Standards, Measurements and Testing Programme). In the experiment use was made of certified reference material ERM-CC144 SEWAGE SLUDGE (Joint Research Centre; JRC). The content of heavy metals (Cd, Cr, Cu, Ni, Pb, and Zn) in certified material was determined by atomic absorption spectrometry using the Avio 200 ICP-OES apparatus (PerkinElmer Inc.). To reduce the sequential extraction time, ultrasound treatment was used instead of long hours of shaking. Sonication was conducted in an ultrasonic bath (Sonic-5; Polsonic). The sonication time was set at 20, 40 and 70 minutes. The frequency, power and temperature during the ultrasound treatment were kept constant. The recovery values of heavy metals obtained by the modified sequential extraction method were at similar levels to those achieved by the conventional one. Moreover, it has also been shown that after only 20 minutes of sonication, the recovery values can be obtained similarly as for the conventional method. In order to check whether the ultrasound waves have a significant impact on the distribution of heavy metals in the chemical fractions of sewage sludge, the percentage share for each element was calculated and the potential ecological risk analysis was conducted. This was possible thanks to the fact that the material used for production of ERM-CC144 (JRC) is sewage sludge of domestic origin. The obtained results revealed that ultrasound treatment does not significantly influence the distribution of analysed heavy metals in the chemical fractions of sewage sludge, with one exception, i.e., Zn. The assessment of the ecological risk was performed using Risk Assessment Code (RAC) index, which includes the content of metals in the most mobile fraction, i.e., bound to carbonates. The calculated values of RAC indicated that Zn posed the highest ecological risk. However, it can be also confirmed that the application of ultrasound treatment in the sequential extraction procedure does not have a significant impact on the interpretation of results of the ecological risk assessment. What is more, it confirms the legitimacy of using the discussed modification in the sequential extraction of heavy metals from sewage sludge.

A surface water mapping framework combining optical and radar remote sensing and its application in China

Satellite remote sensing provides an efficient pathway to map inland surface water extent across different spatial and temporal scales. However, how to monitor the surface water distribution and its spatiotemporal variability via combining optical and radar remote sensing datasets still faces substantial challenges. In this study, we propose a Seamless Surface Water Mapping Framework (SSWMF) which synergizes both optical (MODIS, Landsat 8, Sentinel-2) and SAR (Sentinel-1) imageries. The validity of SSWMF was first proved over the middle and lower reaches of the Yangtze River of China with abundant lake resources, showing an overall accuracy of 90.72%, and the results indicate that SSWMF can provide surface water map with higher spatial and temporal continuity compared to the Joint Research Centre Global Surface Water dataset. Multi-source validation showed that the SSWMF-derived surface water maps can well capture the temporal fluctuation and spatial heterogeneity of water resources over China, with an overall accuracy of 92.39%. Overall, our results suggest that the proposed water mapping framework is promising and is readily applicable to large-scale water resource management and drought/flood monitoring.

Streamflow data availability in Europe: a detailed dataset of interpolated flow-duration curves

Abstract. For about 24 000 river basins across Europe, we provide a continuous representation of the streamflow regime in terms of empirical flow-duration curves (FDCs), which are key signatures of the hydrological behaviour of a catchment and are widely used for supporting decisions on water resource management as well as for assessing hydrologic change. In this study, FDCs are estimated by means of the geostatistical procedure termed total negative deviation top-kriging (TNDTK), starting from the empirical FDCs made available by the Joint Research Centre of the European Commission (DG-JRC) for about 3000 discharge measurement stations across Europe. Consistent with previous studies, TNDTK is shown to provide high accuracy for the entire study area, even with different degrees of reliability, which varies significantly over the study area. In order to provide this kind of information site by site, together with the estimated FDCs, for each catchment we provide indicators of the accuracy and reliability of the performed large-scale geostatistical prediction. The dataset is freely available at the PANGAEA open-access library (Data Publisher for Earth & Environmental Science) at https://doi.org/10.1594/PANGAEA.938975 (Persiano et al., 2021b).

Agriculture from Areas Facing Natural or Other Specific Constraints (ANCs) in Poland, Its Characteristics, Directions of Changes and Challenges in the Context of the European Green Deal

Increasing the European Union’s (EU) current efforts to protect the natural environment, especially in the context of protecting agricultural soils, is one of its basic challenges. The European Commission (EC) is now ready and willing to strongly strengthen protection of the natural environment. Activities are primarily supported by the European Green Deal (EGD) strategy from 2019 and its thematic strategies, as well as the currently revised Common Agricultural Policy (CAP) for 2023–2027. Further direct support for farms from Areas facing Natural or other Specific constraints (ANCs support), compensating for them at least some of the additional costs and lost income related to the difficulties for agricultural production, will be one of the most important actions of the future CAP in the context of the protection of agricultural soils. It should be added that, in recent years, all EU Member States, including Poland (in 2019), have carried out a mandatory new delimitation of ANCs according to the same rules established by the EC Joint Research Center (EC JRC) under the CAP 2014–2020. The aim of the study is to characterize the organizational situation of Polish agriculture, to indicate the direction and strength of the changes taking place in it, as well as the main determinants of its further functioning in areas (communes) with a particularly high saturation of current ANCs, as compared to other areas, with and without ANCs. It is also important to present the economic consequences and development opportunities for farms conducting agricultural production in these areas. The results of the study show the condition of Polish agriculture and changes taking place in this sector in areas with different saturation and specificity of ANCs related to challenges for environmental protection included in the EGD strategy and the current and future CAP. The research results will also provide an important basis for policymakers in undertaking effective agricultural support in ANCs and for the scientific community to develop agricultural research that can meet the most pressing challenges faced in the areas. It should be noted that the study emphasizes the significance of the new institutional economics, the postulates of which can provide solid support for the actions taken to better protect ANCs.

Pre-validation of a reporter gene assay for oxidative stress for the rapid screening of nanobiomaterials.

Engineered nanomaterials have been found to induce oxidative stress. Cellular oxidative stress, in turn, can result in the induction of antioxidant and detoxification enzymes which are controlled by the nuclear erythroid 2-related factor 2 (NRF2) transcription factor. Here, we present the results of a pre-validation study which was conducted within the frame of BIORIMA (“biomaterial risk management”) an EU-funded research and innovation project. For this we used an NRF2 specific chemically activated luciferase expression reporter gene assay derived from the human U2OS osteosarcoma cell line to screen for the induction of the NRF2 mediated gene expression following exposure to biomedically relevant nanobiomaterials. Specifically, we investigated Fe3O4-PEG-PLGA nanomaterials while Ag and TiO2 “benchmark” nanomaterials from the Joint Research Center were used as reference materials. The viability of the cells was determined by using the Alamar blue assay. We performed an interlaboratory study involving seven different laboratories to assess the applicability of the NRF2 reporter gene assay for the screening of nanobiomaterials. The latter work was preceded by online tutorials to ensure that the procedures were harmonized across the different participating laboratories. Fe3O4-PEG-PLGA nanomaterials were found to induce very limited NRF2 mediated gene expression, whereas exposure to Ag nanomaterials induced NRF2 mediated gene expression. TiO2 nanomaterials did not induce NRF2 mediated gene expression. The variability in the results obtained by the participating laboratories was small with mean intra-laboratory standard deviation of 0.16 and mean inter laboratory standard deviation of 0.28 across all NRF2 reporter gene assay results. We conclude that the NRF2 reporter gene assay is a suitable assay for the screening of nanobiomaterial-induced oxidative stress responses.

Predicting environmental concentrations and the potential risk of Plant Protection Products (PPP) on non-target soil organisms accounting for regional and landscape ecological variability in european soils.

Plant Protection Products (PPP) raise concerns as their application may cause effects on some soil organisms considered non-target species which could be highly sensitive to some pesticides. The European Food and Safety Authority (EFSA), in collaboration with the Joint Research Centre (JRC) of the European Commission, has developed guidance and a software tool, Persistence in Soil Analytical Model (PERSAM), for conducting soil exposure assessments. EFSA PPR Panel has published recommendations for the risk assessment of non-target soil organisms. We have used PERSAM for calculating PPPs predicted environmental concentrations (PECs); and used the estimated PEC for assessing potential risks using Toxicity Exposure Ratios (TER) for selected soil organisms and good agricultural practices. Soil characteristics and environmental variables change along a latitudinal axis through the European continent, influencing the availability of PPP, their toxicity upon soil biota, and hence, impacting on the risk characterization. Although PERSAM includes as input geographical information, the information is aggregated and not further detailed in the model outputs. Therefore, there is a need to develop landscape based environmental risk assessment methods addressing regional variability. The objective was to integrate spatially explicit exposure (PECs) and effect data (biological endpoints i.e. LC50, NOEC, etc.) to estimate the risk quotient (TER) of four PPP active substances (esfenvalerate, cyclaniliprole, picoxystrobin, fenamidone) on non-target species accounting European landscape and agricultural variability. The study was focused on the effects produced by the above-mentioned pesticides on two soil organisms: E. fetida earthworms and Folsomia sp. collembolans. After running PERSAM assuming a worst case application of PPPs, PECs in total soil and pore water were obtained for different depths in northern, central and southern European soils. With this data, soil variability and climatic differences among soils divided in three large Euroregions along a latitudinal transect (Northern, Central, Southern Europe) were analysed. Summarising, a trend to accumulate higher PECs and TERs in total soil was observed in the north decreasing towards the south. Higher PECs and TERs could be expected in pore water in southern soils, decreasing towards the north. The risk disparity between pollutant concentrations at different soils compartments should be taken into account for regulatory purposes, as well as the potential landscape variabilities among different Euroregions.

Exhaust Emissions of In-Use Euro 6d-TEMP and Euro 6d Vehicles in WLTP and RDE Conditions, a Comparison

<div class="section abstract"><div class="htmlview paragraph">Air pollution is a major threat to the environment and human health being responsible of more than 350 000 premature deaths every year in the European Union (EU). Road transport accounts for circa 40% of the total NOx emissions and 10% of the particulates emissions of the EU. However, these shares increase significantly in urban areas where 75% of the citizens live. In order to curb pollutant emissions from new vehicles entering the European market, the Euro 6 regulation, setting emission limits for cars and vans, was recently updated with the introduction of a new test procedure in the laboratory, the Worldwide Harmonized Light Vehicle Test Procedure (WLTP), and a novel on-road test performed with Portable Emissions Measurement Systems, the Real Driving Emissions regulation (RDE). Both test procedures WLTP and RDE were designed to represent typical driving conditions and thus help characterizing exhaust emissions of light-duty vehicles in real life operation. This manuscript presents NOx, CO, and solid particulate number PN emissions of 53 gasoline and diesel passenger cars type-approved in the EU after the entry into force of the WLTP and RDE (i.e., meeting the Euro 6d-TEMP and Euro 6d standards). Emissions data over WLTP and RDE tests on in-use vehicles was collected by the Joint Research Center (JRC) of the European Commission in the period 2018-2021. Emissions are characterized by powertrain, fuel type, and test procedure. All vehicles comply well with Euro 6 emission limits and no statistically significant differences are found in NOx, CO, and PN emissions measured over the complete WLTP and RDE tests, both for gasoline and diesel vehicles.</div></div>

Digital Storytelling Through the European Commission’s Africa Knowledge Platform to Bridge the Science-Policy Interface for Raw Materials

The international science-policy interface increasingly needs knowledge brokers to convey technical evidence to non-specialists in an engaging way. The European Commission’s Joint Research Centre (JRC) has a long track-record of scientific knowledge on Africa’s developmental context, but this knowledge is often fragmented and difficult to access, limiting its uptake by policymakers and other stakeholders. To overcome this, the JRC developed the Africa Knowledge Platform ( https://africa-knowledge-platform.ec.europa.eu/ ), a web-based entry-point to knowledge that evolves constantly to best support the European Union’s objective of deepening its partnership with Africa. This highly visual and easy-to-use platform brings together datasets, narratives, interactive tools, and partnerships across more than 60 disciplines and policy priorities. Here, we introduce the Africa Knowledge Platform, focusing specifically on using digital storytelling to communicate policy-relevant research on Africa’s raw materials. We present two geographically explicit narratives on (1) critical raw materials for low carbon and digital technologies and (2) monitoring gold mining in remote parts of central Africa using satellite technology. Each narrative uses interactive data and accessible language to communicate relevant research from the JRC and other sources within the context of policies including the EU-Africa Strategy, the European Green Deal and its Circular Economy Action Plan, the African Union’s Mining Vision and international development agendas such as the Sustainable Development Goals. Ultimately, we reflect on how the Africa Knowledge Platform can bridge the gap between scientists and policymakers, emphasising the opportunities and caveats for knowledge brokerage across complex science-policy contexts.

Seismic Performance of Strengthened Slab-Column Connections in a Full-Scale Test

ABSTRACT Strengthening of flat slab-column connections to resist imposed lateral drifts is often required for older reinforced concrete structures in which the flat slabs were typically designed to resist gravity load only or have been designed for less stringent requirements. The complex stress state around the columns means that strong experimental evidence is required for the repair and strengthening techniques to be adopted with confidence in practice. Although a significant amount of research has been devoted to strengthening of slab-column connections, a series of limitations still remain. A thorough literature review revealed that only relatively thin and isolated specimens have been tested under seismic-type loading and realistic strengthening scenarios. To overcome these limitations, a full-scale two-story flat slab building specimen was tested at the European Commission’s Joint Research Centre – ELSA Laboratory in Ispra, Italy. This paper describes and analyzes the results obtained from the last of a series of phases, on repaired and strengthened internal and external slab-column connections using post-installed bolts. Compared with previous tests, the full-scale building specimen has a thicker slab (200 mm), realistic slab continuity conditions and the connections were strengthened after they suffered damage from gravity loading and previous lateral loading phases. The results show that post-installed bolts are efficient even under the described conditions (i.e. damaged and repaired specimens with realistic thickness), and punching shear failure was prevented in the strengthened connections.

A Fast Data-Driven Tool for Flood Risk Assessment in Urban Areas

Post-disaster flood risk assessment is extremely difficult owing to the great uncertainties involved in all parts of the assessment exercise, e.g., the uncertainty of hydrologic–hydraulic models and depth–damage curves. In the present study, a robust and fast data-driven tool for residential flood risk assessment is introduced. The proposed tool can be used by scientists, practitioners and/or stakeholders as a first step for better understanding and quantifying flood risk in monetary terms. Another contribution of the present study is the fitting of an equation through depth–damage points provided by the Joint Research Center (JRC). The approach is based on hydrologic simulations for different return periods, employing a free and widely used software, HEC-HMS. Moreover, flood depths for the study area are estimated based on hydrodynamic simulations employing the HEC-RAS software and the Inverse Distance Weighting (IDW) interpolation method. Finally, flood risk, in monetary terms, is determined based on the flood depths derived by the coupling of hydrodynamic simulations and the IDW method, depth–damage curves reported in the literature, vulnerability of residential areas and the residential exposure derived by employing GIS tools. The proposed tool is applied in a highly urbanized and flood-prone area, Mandra city, in the Attica region of Greece. The results are maps of flood depths and flood risk maps for specific return periods. Overall, the results derived from the application of the proposed approach reveal that the tool can be highly effective for post-disaster flood risk management. However, it must be noted that additional information and post-disaster data are needed for the verification of the damages from floods. Additional information can result in better calibration, validation and overall performance of the proposed flood risk assessment tool.

A Comparison of Conventional and Ultrasound-Assisted BCR Sequential Extraction Methods for the Fractionation of Heavy Metals in Sewage Sludge of Different Characteristics.

The purpose of this study was to determine the heavy metal (HM: Cd, Cr, Cu, Ni, Pb, Zn, and Hg) content in particular chemical fractions (forms) of sewage sludge with different characteristics (primary and dewatered sludge) using conventional (CSE) and ultrasound-assisted (USE) BCR sequential extraction methods (Community Bureau of Reference, now the Standards, Measurements and Testing Programme). The concentrations of HMs were determined using inductively coupled plasma optical spectrometry (ICP-OES). Only mercury was assayed with cold vapor atomic absorption spectrometry (CVAAS). Ultrasound treatment was conducted in the ultrasonic bath (Sonic 5, Polsonic). The optimal sonication time (30 min) was determined using ERM-CC144 (Joint Research Center; JCR) certified reference material. The conducted experiment revealed that the use of ultrasound waves shortened the extraction time to 4 h and 30 min (Stages I to III). The recoveries (RM) of heavy metals ranged from 62.8% to 130.2% (CSE) and from 79.8% to 135.7% (USE) for primary sludge, and from 87.2% to 113.2% (CSE) and from 87.8% to 112.0% (USE) for dewatered sludge. The only exception was Hg in dewatered sludge. The conducted research revealed minor differences in the concentrations and fractionation patterns for Cd, Ni, and Zn extracted from sludge samples by the tested methods. However, it was confirmed that the above findings do not significantly affect the results of a potential ecological risk assessment (with minor exceptions for Cd and Zn in the primary sludge), which is extremely essential for the natural use of sludge, and especially dewatered sludge (the final sludge). The shorter extraction time and lower energy consumption prove that ultrasound-assisted extraction is a fast and simple method for HM fractionation, and that it provides an alternative to the conventional procedure. Therefore, it can be considered a “green method” for the assessment of the bioavailability and mobility of heavy metals in solid samples.

Robotic Competitions to Design Future Transport Systems: The Case of JRC AUTOTRAC 2020

Vehicle automation and connectivity bring new opportunities for safe and sustainable mobility in urban and highway networks. Such opportunities are however not directly associated with traffic flow improvements. Research on exploitation of connected and automated vehicles (CAVs) toward a more efficient traffic currently remains at a theoretical level, and/or based on simulation models with limited reliability. Furthermore, testing CAVs in the real world is still costly and very challenging from an implementation perspective. A possible alternative is to use automated robots. By designing and testing both the low- and the high-level controllers of CAVs, it is indeed possible to reach a better understanding of the challenges that future vehicles will need to face. Robotic applications can effectively test these challenges within a wide variety of research communities—for example, via robotic competitions. Along this direction, the Joint Research Centre has organized the first European robotic traffic competition for automated miniature vehicles. Each team participated with four robots and was judged based on a set of indicators that assess the collective behaviors of the vehicles. Results show the suitability of the methodology with different teams proposing completely different approaches to deal with the challenge and thus achieving different results. Future competitions may further raise awareness about the possibility of using CAVs to improve traffic and to engage with a broader community to design systems that are really capable of achieving this goal.

Spatio-temporal characterization of surface water dynamics with Landsat in endorheic Cuvelai-Etosha Basin (1990–2021)

Socio-economic damages caused by extreme floods have been increasing rapidly in recent years, mainly driven by changes in the climate and modulated by increasing human population in deltic areas and floodplains. The Cuvelai-Etosha Basin (CEB) in southern Africa, covering southern Angola and northern Namibia, experiences socially and economically devastating extreme floods. Yet, accurate information on past and current surface water changes and dynamics is lacking. Here, we estimate and map the surface water extents in the CEB and its surroundings (CEB + S) for 32 years (1990–2021) from Landsat data using random forest models to provide long-term baseline information on surface water changes and dynamics. Based on the reference data, a total of 15,677 ± 1080 km2 have been inundated by surface water in the CEB + S during 1990–2021. This extent was accurately mapped by our local water extent product (mapped area = 16,273 km2, user’s accuracy = 91.5 ± 2.5%, producer’s accuracy = 91.1 ± 6%). With user’s and producer’s accuracy of 91%, our overall water extent provides the first most accurate long-term baseline information on surface water inundation in CEB + S necessary for local spatial planning processes to minimise future negative impacts of floods in the basin. Interannual variability of surface water extent is, however, high, with water extent ranging from 520.8 ± 375.7 km2 to 12372.3 ± 1154.7 km2 during the 1990–2021 period. The largest annual water extents (>10,000 km2) were recorded in 2006, 2008, 2009, 2011, and 2017, whereas the smallest extents (<1000 km2) were recorded in 1992 and 2019. We found that over 40% of the area inundated in the CEB + S during 1990–2021 was inundated less than 9 times. With human population increasing rapidly in the CEB + S, rarely inundated areas with short water residence could become a prime target for human settlements, which may lead to huge socio-economic damages during extreme floods if no preventive measures are put in place. Globally available surface water maps from the Global Land Analysis and Discovery (GLAD) and European Commission’s Joint Research Centre (JRC) did not provide realistic surface water extent for CEB + S, especially during years with extreme floods. Therefore, locally adopted product for operational monitoring of surface water in the CEB + S is needed to provide accurate information for informing spatial planning processes and surface water resource management strategies in this endorheic basin and help minimise future negative impacts of floods.

Detecting, extracting, and mapping of inland surface water using Landsat 8 Operational Land Imager: A case study of Pune district, India.

Background: Recent developments in optical satellite remote sensing have led to a new era in the detection of surface water with its changing dynamics. This study presents the creation of surface water inventory for a part of Pune district (an administrative area), in India using the Landsat 8 Operational Land Imager (OLI) and a multi spectral water indices method. Methods: A total of 13 Landsat 8 OLI cloud free images were analyzed for surface water detection. Modified Normalized Difference Water Index (MNDWI) spectral index method was employed to enhance the water pixels in the image. Water and non-water areas in the map were discriminated using the threshold slicing method with a trial and error approach. The accuracy analysis based on kappa coefficient and percentage of the correctly classified pixels was presented by comparing MNDWI maps with corresponding Joint Research Centre (JRC) Global Surface Water Explorer (GSWE) images. The changes in the surface area of eight freshwater reservoirs within the study area (Bhama Askhed, Bhatghar, Chaskaman, Khadakwasala, Mulashi, Panshet, Shivrata, and Varasgaon) for the year 2016 were analyzed and compared to GSWE time series water databases for accuracy assessment. The annual water occurrence map with percentage water occurrence on a yearly basis was also prepared. Results: The kappa coefficient agreement between MNDWI images and GSWE images is in the range of 0.56 to 0.96 with an average agreement of 0.82 indicating a strong level of agreement. Conclusions: MNDWI is easy to implement and is a sufficiently accurate method to separate water bodies from satellite images. The accuracy of the result depends on the clarity of image and selection of an optimum threshold method. The resulting accuracy and performance of the proposed algorithm will improve with implementation of automatic threshold selection methods and comparative studies for other spectral indices methods.

EFSA International Workshop on RA of Combined Exposure to Multiple Chemicals

Human Risk Assessment (RA) of combined exposure to multiple chemicals follows the steps of RA namely problem formulation, exposure assessment, hazard assessment and risk characterisation. Over the last decade, scientific advisory bodies have published a range of harmonised guidance documents to provide practical approaches for risk assessors. These include the WHO, the US-EPA, the Joint Research Centre (JRC) of the European Commission, the OECD and the recent EFSA MIXTOX guidance document dealing with harmonised methodologies for the human health, animal health and ecological RA areas. On May 21st 2021, the Scientific Committee of EFSA published a draft guidance document on scientific criteria to group chemicals in assessment groups using hazard-driven criteria and prioritisation methods using exposure-driven and risk-based approaches. The latter guidance and future challenges were the topic of this international workshop which was held online in the afternoons of the 18th, 19th and 20st October 2021. First, a plenary session provided overviews of European and international activities in the field including WHO, OECD, US-EPA, JRC and EFSA. With a total of 118 participants including national and international scientific advisory bodies, academics and researchers, NGOs, industry, risk assessors, risk managers, four discussions groups were created for three break-out group sessions: 1) Hazard-driven criteria for grouping multiple chemicals into assessment groups; 2) Exposure-driven and risk-based criteria for the prioritisation of multiple chemicals 3) Data gaps and future challenges for human health and environmental RA of combined exposure to multiple chemicals to identify priority topics of international relevance and a way forward to address these topics. A final discussion and wrap-up session concluded the meeting. This event report provides a summary of the discussions together with conclusions and recommendations.

Dynamic Optimal Reinsurance and Dividend Payout in Finite Time Horizon

This paper studies a dynamic optimal reinsurance and dividend-payout problem for an insurance company in a finite time horizon. The goal of the company is to maximize the expected cumulative discounted dividend payouts until bankruptcy or maturity, whichever comes earlier. The company is allowed to buy reinsurance contracts dynamically over the whole time horizon to cede its risk exposure with other reinsurance companies. This is a mixed singular–classical stochastic control problem, and the corresponding Hamilton–Jacobi–Bellman equation is a variational inequality with a fully nonlinear operator and subject to a gradient constraint. We obtain the [Formula: see text] smoothness of the value function and a comparison principle for its gradient function by the penalty approximation method so that one can establish an efficient numerical scheme to compute the value function. We find that the surplus-time space can be divided into three nonoverlapping regions by a risk-magnitude and time-dependent reinsurance barrier and a time-dependent dividend-payout barrier. The insurance company should be exposed to a higher risk as its surplus increases, be exposed to the entire risk once its surplus upward crosses the reinsurance barrier, and pay out all its reserves exceeding the dividend-payout barrier. The estimated localities of these regions are also provided. Funding: This work was supported by the Hong Kong Research Grants Council [Grants GRF 15202421 and GRF 15202817], the Guangdong Basic and Applied Basic Research Foundation [Grants 2021A1515012031 and 2022A1515010263], the National Natural Science Foundation of China [Grants 11901244 and 11971409], the PolyU-SDU Joint Research Center on Financial Mathematics, the CAS AMSS-PolyU Joint Laboratory of Applied Mathematics, and Hong Kong Polytechnic University.

Monitoring and Predicting Channel Morphology of the Tongtian River, Headwater of the Yangtze River Using Landsat Images and Lightweight Neural Network

The Tongtian River is the source of the Yangtze River and is a national key ecological reserve in China. Monitoring and predicting the changes and mechanisms of the Tongtian River channel morphology are beneficial to protecting the “Asian Water Tower”. This study aims to quantitatively monitor and predict the accretion and erosion area of the Tongtian River channel morphology during the past 30 years (1990–2020). Firstly, the water bodies of the Tongtian River were extracted and the accretion and erosion areas were quantified using 1108 Landsat images based on the combined method of three water-body indices and a threshold, and the surface-water dataset provided by the European Commission Joint Research Centre. Secondly, an intelligent lightweight neural-network model was constructed to predict and analyze the accretion and erosion area of the Tongtian River. Results indicate that the Tongtian River experienced apparent accretion and erosion with a total area of 98.3 and 94.9 km2, respectively, during 1990–2020. The braided (meandering) reaches at the upper (lower) Tongtian River exhibit an overall trend of accretion (erosion). The Tongtian River channel morphology was determined by the synergistic effect of sediment-transport velocity and streamflow. The lightweight neural network well-reproduced the complex nonlinear processes in the river-channel morphology with a final prediction error of 0.0048 km2 for the training session and 4.6 km2 for the test session. Results in this study provide more effective, reasonable, and scientific decision-making aids for monitoring, protecting, understanding, and mining the evolution characteristics of rivers, especially the complex change processes of braided river channels in alpine regions and developing countries.

Possible accident scenarios related to the Spent Fuel Pool operating events

After the accident in Fukushima Daiichi NPP, the Nuclear Energy Agency Committee on the Safety of Nuclear Installations (OECD/NEA CSNI) initiated activities to address some technical issues. As a one of results, the Status report on Spent Fuel Pools (SFPs) under Loss of Cooling Accident Conditions was created. To give a valuable contribution to the post-Fukushima accident decision making process, brief summaries were produced on:&#x0D; - The status of SFP accident and mitigation strategies;&#x0D; - Assessment of current experimental and analytical knowledge about loss of cooling accidents in SFPs and their associated mitigation strategies;&#x0D; - The strengths and weaknesses of analytical methods used in codes to predict SFP accident evolution and assess the efficiency of different cooling mechanisms for mitigation of such accidents;&#x0D; - Identification of additional research activities required to address gaps in the understanding of relevant phenomenological processes, where analytical tool deficiencies exist, and to reduce the uncertainties in this understanding.&#x0D; The final report was approved by OECD/NEA CSNI in December 2014 with the reference NEA/CSNI/R(2015)2 and it is available for download on the OECD website http://www.oecdnea. org/nsd/docs/2015/csni-r2015-2.pdf. Joint Research Centre of European Commission took the leading role in creation of the chapter about possible accident scenarios, past accidents and precursor events. Evaluations of past events where SFP cooling has been lost show that malfunctions of the SFP cooling system are in most cases caused by inoperable cooling pumps. The other important causes are inadvertent diversion of coolant flow and Loss of ultimate heat sink. This paper is providing short general report overview and more details about JRC contribution.

The Role of Cooling Centers in Protecting Vulnerable Individuals from Extreme Heat.

The Role of Cooling Centers in Protecting Vulnerable Individuals from Extreme Heat.