Natural Discharge Research Articles

Advancing water security in Africa with new high-resolution discharge data

VegDischarge v1, which covers over 64,000 river segments in Africa, is a natural river discharge dataset produced by coupled modeling; the agro-hydrologic VegET model and the mizuRoute routing model for the period 2001-2021. Using remote sensing data and hydrological modeling system, the 1-km runoff field simulated by VegET, was routed with mizuRoute. Performance metrics show strong model reliability, with R² of 0.5–0.9, NSE of 0.6–0.9, and KGE of 0.5–0.8 at the continental scale. The total average annual discharge for Africa is quantified at 3271.4 km³·year−1, with contributions to oceanic basins: 1000.0 km³·year−1 to the North Atlantic, primarily from the Senegal, Gambia, Volta, and Niger Rivers; 1327.2 km³·year−1 to the South Atlantic, largely from the Congo River; 214.7 km³·year−1 to the Mediterranean Sea, predominantly from the Nile River; and 729.4 km³·year−1 to the Indian Ocean, with inputs from rivers such as the Zambezi. The dataset is valuable for stakeholders and researchers to understand water availability, its temporal and spatial variations that affect water-related infrastructure planning, sustainable resource allocation, and the development of climate resilience strategies.

Influence of altered freshwater discharge on the seasonality of nutrient distributions near La Grande River, northeastern James Bay, Québec

In subarctic marine environments, nutrient stocks are replenished through physical and biogeochemical processes in winter, largely setting an upper limit on new primary production for the next growing season. In spring, marine nutrient stocks are modified by freshwater-associated additions, especially in coastal areas. Hydroelectric development of the La Grande River (LGR) in northern Québec has shifted the timing of peak freshwater discharge from spring into winter, producing 10 times the natural winter discharge. Here, we considered salinity, oxygen isotope ratio (δ18O), and nutrient (nitrate, phosphate) data from coastal waters of northeast James Bay in different seasons of 2016 and 2017. We quantified two main freshwater sources, LGR and sea-ice melt, established by freshwater tracers, and their influence on coastal nutrient distributions. Our results show that LGR is the dominant source of freshwater to coastal waters throughout the year, especially during winter, and an important source of nitrate to nitrogen-limited coastal waters (winter concentrations of 4.53 μM versus 3.18 μM in ambient seawater). Despite being a poor phosphate source (0.11 μM versus 0.66 μM in ambient seawater), LGR provides the largest portion of the phosphate stock in surface waters near its mouth. LGR regulation has changed the pattern of natural fluvial nitrate inputs: what was observed in spring (pre-development) is now observed in winter (post-development). Thus, high winter surface nitrate stocks (22.5 mmol m−2) are available to support primary production, but are dispersed to offshore areas prior to the onset of the growing season, which begins only after the return of light. In northeast James Bay, the timing and magnitude of primary production, dependent on nutrients in the water column, is expected to have been impacted by altered freshwater input, reducing overall production in local areas and potentially increasing production further downstream with cascading effects on the marine ecosystem.

Anthropogenic climate change has influenced global river flow seasonality.

Riverine ecosystems have adapted to natural discharge variations across seasons. However, evidence suggesting that climate change has already impacted magnitudes of river flow seasonality is limited to local studies, mainly focusing on changes of mean or extreme flows. This study introduces the use of apportionment entropy as a robust measure to assess flow-volume nonuniformity across seasons, enabling a global analysis. We found that ~21% of long-term river gauging stations exhibit significant alterations in seasonal flow distributions, but two-thirds of these are unrelated to trends in annual mean discharge. By combining a data-driven runoff reconstruction with state-of-the-art hydrological simulations, we identified a discernible weakening of river flow seasonality in northern high latitudes (above 50°N), a phenomenon directly linked to anthropogenic climate forcing.

Expanding Karst Groundwater Tracing Techniques: Incorporating Population Genetic and Isotopic Data to Enhance Flow-Path Characterization

Karst aquifers are unique among groundwater systems because of variable permeability and flow-path organization changes resulting from dissolution processes. Over time, changes in flow-path connectivity complicate interpretations of conduit network evolution in karst hydrogeology. Natural and artificial tracer techniques have long provided critical information for protecting karst aquifers and understanding the potential impacts on ecosystems and human populations. Conventional tracer methods are useful in karst hydrogeologic studies for delineating flow paths and defining recharge, storage, and discharge properties. However, these methods only provide snapshots of the current conditions and do not provide sufficient information to understand the changes in interconnection or larger-scale evolution of flow paths in the aquifer over time. With advances in population genetics, it is possible to assess population connectivity, which may provide greater insights into complex groundwater flow paths. To assess this potential, we combined the more traditional approaches collected in this and associated studies, including artificial (dye) and natural (geochemistry, isotopes, and discharge) tracers, with the population genetic data of a groundwater crustacean to determine whether these data can provide insights into seasonal or longer changes in connections between conduits. The data collected included dye trace, hydrographs, geochemistry, and asellid isopod (Caecidotea bicrenenta) population genetics in Fern Cave, AL, USA, a 25 km-long cave system. Combined, these data show the connections between two separate flow paths during flood events as the downstream populations of isopods belonging to the same subpopulation were measured in both systems. Additionally, the sub-populations found in higher elevations of the cave suggest a highly interconnected unsaturated zone that allows for genetic movement in the vadose zone. Although upstream populations show some similarities in genetics, hydrologic barriers, in the form of large waterfalls, likely separate populations within the same stream.

Pulsed electric field drives chemical-free membrane stripping for high ammonia recovery from urine

Recovering ammonia from waste streams (e.g., urine) is highly desirable to reduce natural gas-based NH3 production and nitrogen discharge into the water environment. Electrochemical membrane stripping is an attractive alternative because it can drive NH4+ transformation to NH3 via cathodic OH− production; however, the conventional configurations suffer from relatively low ammonia recovery (<80 %) and significant acid/material usage for ammonia adsorption. To this end, we develop a novel stack system that simply uses an oxygen evolution reaction to in-situ produce acid from water, enabling chemical-free ammonia recovery from synthetic urine. In batch mode, the percentage removal and recovery increased respectively from 74.5 % to 97.9 % and 81.8 % to 92.7 % when the electrode pairs increased from 2 to 4 in the stack system. To address the gas-sparging issue that deteriorated ammonia recovery in continuous operation, pulsed electric field (PEF) mode was applied, resulting in ∼100 % recovery under optimized conditions. At an ammonia removal rate of 35.1 g-N m−2 h−1 and electrical energy consumption of 28.9 kWh kg-N−1, our chemical-free system in PEF mode has achieved significantly higher ammonia recovery (>90 %) from synthetic urine. The total cost to recover 1 kg of NH3–N from real human urine was $15.9 in the proposed system. Results of this study demonstrate that this novel approach holds great promise for high ammonia recovery from waste streams, opening a new pathway toward sustainable nitrogen management.

Aquifer Management Establishing a Tradable Water Rights System: The Effect of Natural Discharge and Salinity

Economic instruments such as tradable water rights systems have been proposed as cost-effective methods for managing groundwater. The relevant literature shows that the majority of the relevant studies do not consider aquifer’s natural discharge, which is expected to have a significant impact on the determination of the optimal groundwater management policy. This paper attempts to highlight the impact of considering natural discharge in the formulation of groundwater management policies. Thus, two different cases of aquifer management are considered and the corresponding time-dynamic problems are solved by considering natural discharge in order to derive optimal trajectories for a number of key variables. These cases are (1) non-intervention – full competition and (2) intervention with a tradable water rights system. The results obtained from simulations on a coastal aquifer show that indeed not considering the natural discharge leads to an overestimation of the benefits from groundwater consumption that can reach 5.79% in the case of non-intervention and in the case of intervention with a tradable water rights system.

Hydrochemical Characteristics and Formation Causes of Ground Karst Water Systems in Gudui Spring Catchment

As one of the famous karst springs in Shanxi Province, the Gudui spring is the only medium-low temperature hot spring, with a long history of development and a rich cultural accumulation. The karst groundwater in the Gudui spring catchment was taken as the research object. Through systematic sample collection and isotope analysis, hydrochemistry (Durov map, ion ratio, Gibbs map, and hydrogen and oxygen isotope) methods were comprehensively used to analyze groundwater hydrochemistry and groundwater system runoff characteristics. The87Sr/86Sr value of karst groundwater in the Gudui spring catchment was 0.709 to 0.717, and the Mg/(Mg+Ca) value was 0.27 to 0.74. By analyzing the Sr isotope composition and Mg/(Mg+Ca) and 1/Sr variation characteristics, it was concluded that the karst groundwater in the Gudui spring catchment was a mixture of deep hot water and shallow cold water. The karst water subsystem of Nanliang spring presented the characteristics of carbonate stratum runoff. The karst water subsystem of Fuling Mountain Gaoxian Haitou spring and the deep circulation subsystem of Houma Basin exhibited the runoff characteristics of carbonate rock and igneous rock strata. The karst water subsystem of Taiershan Jiuyuanshan Gudui spring presented the runoff characteristics of carbonate rock and ancient silicoaluminate strata. The δ18O value in karst groundwater of Guodui spring area ranged from -11.46‰ to -7.81‰, and the average value was -10.08‰. The range of the δD value was -83.7‰ to -60.8‰, and the average value was -73.6‰. This showed that karst groundwater in the spring area was the result of mixing of various types of water. Through comparative analysis of hydrogen and oxygen isotopes of 2014 and 2021 sampling points at the same location, it was concluded that the change in water samples at the Guduiquan resulted from the gradual accumulation of water supplied by Sanquan Reservoir. The change in Sanquan Reservoir was due to the influence of Yellow River diversion. The karst groundwater in the spring area were characterized by large calcium ion, magnesium ion, and sodium ion values; a small potassium ion value; a large sulfate value; and a small chloride value. The hydrochemical types of karst groundwater in Gudui spring catchment could be divided into SO4-Na, SO4-Ca, HCO3-Na, HCO3-Mg, HCO3-Ca, and Cl-Na. The hydrochemical types of karst groundwater showed evident hydrochemical composition zoning from HCO3-Ca·Mg→HCO3·SO4-Ca·Mg→SO4·HCO3-Na·Ca→SO4·Cl-Na·Ca. According to the comprehensive analysis of hydrochemical isotope and hydrogeological conditions, the karst water subsystem of Nanliang spring was primarily recharged by rainfall infiltration in the exposed limestone area and river infiltration, and its karst groundwater was recharged by runoff from south to north to the karst water subsystem of Fuling Mountain Gaoxian Haitou spring and the deep circulation subsystem of Houma Basin. The karst water subsystem of Taier Jiuyuan Mountain Gudui spring received rainfall infiltration supplement and upstream runoff supplement from the exposed limestone area. Its karst groundwater flowed from north to south and received the supply of Sanquan Reservoir from Yellow River water in the natural discharge area of Gudui spring.

Receptor model-based source apportionment and ecological risk assessment of metals in sediment of river Ganga, India

Ganga river surface sediment was sampled from 11 locations, which revealed average concentrations (mg/kg) of metals in the order Mn (296.93) > Zn (61.94) > Cr (54.82) > Cu (30.19) > Pb (24.42) > Cd (0.36). Sediment quality guidelines showed metals rarely to occasionally exhibit adverse biological effects. Indices like potential ecological risk, contamination security index, hazard quotients, multiple probable effect concentrations quality, mean probable effects level quotients, mean effects range median quotient suggest nil to a very low level of pollution with low ecological risk. Contamination factor, geo accumulation index, enrichment factor, quantification of contamination revealed that Pb and Cd originated from anthropogenic activities. APCS-MLR model revealed that metals contributed from natural sources (Zn, Mn, Cr; 20.18 %), industrial-agricultural (Cd; 21.35 %); and discharge of paints, Pb batteries, fossil fuel (Pb; 8.49 %). Present findings will serve as an effective guideline for managing and ameliorating pollution in the river system.

Characterizing the transitory groundwater-surface water interaction and its environmental consequence of a riverside karst pool

Exchange between groundwater (GW) and surface water (SW) is a common occurrence in karst water systems through sinking stream disappearance or groundwater emergence. However, the transitory GW-SW interaction caused by river backflowing into a spring is poorly observed and understood. In this study, we present an approach for characterizing the influence of GW-SW interaction in a karst spring by integrating high-resolution hydrology, carefully selected hydrochemistry monitoring and precise microbe measurements. The spring-fed pool water conditions can be distinguished as high, medium, and low-water level periods in a hydrological year. The high-water level accounts for <1 % in a year, while it is associated with the hydrological regimes of backflooding states. The inflow of river backflow was found to be 4.4 times that of the natural discharge of spring water during a rainfall event. The duration of river intrusion into the spring or karst conduit could be assessed by jointly interpreting hydrography and physicochemical signatures, while the lasting environmental consequences should be evaluated together with biotic factors such as Escherichia coli. The GW-SW interaction induced by river backflow has led to the retention of river water in a pool, spring, and karst conduit for 132, 94, and 56 h, respectively. Despite turbidity returning to normal levels after 56 h, E.coli continued to persist for an extended duration. Our study reveals that despite the transient nature of GW-SW induced by river backflow on the hydrograph, they present a lasting risk of contamination from heavy metals, organic matter, and microorganisms. This extended influence can persist within a karst aquifer lacking a hyporheic zone. This research contributes to the quantification of processes involved in transitory GW-SW interaction in a karst spring, and it highlights the underestimation of GW-SW interactions in karst water systems, which might negatively impact water resources management.

Assessment of thermal water and energy recoverable rate based on express method: A case study of Reshuiwei geothermal field

Assessment of geothermal resources is the vital and difficult work during geothermal resources utilization. The aims of this study are to: (1) estimate the natural thermal water discharge and the mass flow rates of recoverable thermal water in boreholes by using “express method”. (2) evaluate the geothermal water and energy resources through estimating the convective heat and mass discharge/deep recharge of this geothermal field based on the calculation results. Results show that this geothermal field should be divided into three sections to calculate hot water resources: Reshuiwei section, Miaowan section and Dongqingshu downward section. Main controlling fault zones are F3, F6 and F7 fault zones, respectively. The total reached mass flow rates of recoverable thermal water are 49.32 kg/s. Reshuiwei section is a suitable area for underground hot water comprehensive utilization. The reached recoverable heat rates are 15.031 MW. In addition, the reservoir temperature potential of Reshuiwei geothermal field would be about 182.95 °C, the conceptual model of this geothermal field formation is summarized. Conclusions drawn from this study would provide reference for geothermal resources assessment of all geothermal fields.

Dissolution of anthropogenic and natural hydrogen sulfide in deep-ocean conditions

ABSTRACT Natural and anthropogenic event information helped to simulate the physical–chemical behavior of hydrogen sulfide (H2S) in a deep oil spill and a hypothetical deep-ocean hydrothermal discharge. This research led to the development of the Lagrangian model of the discharge plumes in both cases and also analyzed the profiles of the H2S concentration at different depths taking into account its dissolution in ocean water and oceanographic conditions, such as thermohaline stratification, current fields, as well as the characteristics of the spilled hydrocarbon and the hydrothermal. The results revealed a first approximation in the identification of the dynamic behavior of the concentration profiles of H2S as a function of the oceanographic conditions. Hydrogen sulfide concentrations vary between natural and anthropogenic discharges at various depths, leading to a numerical model for applying in chemical oceanography.

Origin of some hot springs as conceptual geothermal models

Hot springs act as natural discharge points of geothermal waters. Hot springs exhibit a wide variety of geothermal activities and hydrochemical constituents and occur in locations with varying tectonic backgrounds. The occurrence of hot springs is controlled by a number of natural geological, tectonic, geothermal and hydrogeological factors. These factors include the basic components of geothermal systems such as geothermal reservoirs, caprocks, heat sources, water sources and permeable pathways. Variations of these factors are characteristics of geothermal systems, such as geothermal systems of the basin type, fold-controlled type, fault-controlled type, magma-related type, and contact zone-controlled type. There are several geothermal systems of combination types, including geothermal systems of the basin and fault-controlled type, anticline and fault-controlled type, volcano and fault controlled type and so on. Forty-four conceptual models, shown in profiles, were used to schematically describe the origin of various hot springs and have been summarized and presented in this paper for better understanding the origin of hot springs. Hot springs may be the discharge points of regional and intermediate flow in a groundwater system where the local, intermediate and regional flow exist. Three challenges for the future studies of the origin of hot springs are also presented.

Human activities have more impacts on the recent discharge reduction of the largest tributary of the Yellow River relative to last three centuries

How to quantitatively decouple the impacts of climate change and human activities on river discharge changes is a challenge in current global change research. As the largest tributary of the Yellow River (YR), the Weihe River (WR) is a typical river whose discharge is influenced by climate change and human activities. Here, we first attempt to obtain the normal-flow season and high-flow season discharge in the lower reaches of the WR by using tree rings and historical documents, respectively. The relationship between natural discharge in the two seasons is unstable and complex since 1678. Using an innovative method, we reconstructed the natural discharge from March to October (DM-O), which explains >73 % of the variance in the observed DM-O during the modeling period 1935–1970. There were 44 high-flow years, 6 extremely high-flow years, 48 low-flow years and 8 extremely low-flow years from 1678 to 2008. The contribution of WR annual discharge to the YR is 17 % over the past three centuries, and their natural discharge changes synchronously rise and fall. Human activities, such as the construction of reservoirs and check-dams, agricultural irrigation and domestic and industrial water consumption, have more impacts than climate change on the decrease in the observed discharge. In total, 53.5 % of the discharge reduction since 1971 is due to human activities, and 46.5 % is due to climate change. In addition, this study provides an important model for how to quantify the influences of human activities and nature on discharge reduction and to reconstruct seasonal resolution climate in global change studies.

Development of environmental management accounting system: a conceptual approach

With the rise of environmental problems caused by human activities, such as misuse of natural resources, rapid deforestation, and discharge of radioactive and other chemical waste into water bodies, soil and the atmosphere, environmental management accounting has emerged as a tool for promoting sustainable development and reducing negative environmental impacts in businesses. This area of accounting provides a means for analyzing, assessing, controlling, and managing the environmental performance of companies. However, there is a dearth of studies in the scientific literature that systematically assess the potential for introducing and developing environmental management accounting in an enterprise. Therefore, this study aims to identify the areas, instruments, outcome, impact measures, and other elements of environmental management accounting, and integrate them in a targeted manner to develop a conceptualized environmental management accounting system. The results of the literature review and systematic analysis are summarized to provide a conceptual framework for an environmental management accounting system consisting of the following elements: 1) objectives; 2) inputs; 3) processes; 4) outputs/outcomes; 5) feedback; and 6) external environmental conditions. The introduction of such a system would improve the development of environmental management accounting for the long-term sustainability and eco-efficiency of companies.

Groundwater Quality and Health: Making the Invisible Visible.

Linking groundwater quality to health will make the invisible groundwater visible, but there are knowledge gaps to understand the linkage which requires cross-disciplinary convergent research. The substances in groundwater that are critical to health can be classified into five types according to the sources and characteristics: geogenic substances, biogenic elements, anthropogenic contaminants, emerging contaminants, and pathogens. The most intriguing questions are related to quantitative assessment of human health and ecological risks of exposure to the critical substances via natural or induced artificial groundwater discharge: What is the list of critical substances released from discharging groundwater, and what are the pathways of the receptors' exposure to the critical substances? How to quantify the flux of critical substances during groundwater discharge? What procedures can we follow to assess human health and ecological risks of groundwater discharge? Answering these questions is fundamental for humans to deal with the challenges of water security and health risks related to groundwater quality. This perspective provides recent progresses, knowledge gaps, and future trends in understanding the linkage between groundwater quality and health.

Organisation of Fish Assemblage in the Mekong Delta as a Potential Indicator of Salt Water Intrusion

The problem of salt water intrusion into the Mekong Delta is a research topic involving various branches of science. Among the causes of this phenomenon are global sea level rise and regulation of the natural river discharge due to hydropower dam construction. The scale of the delta and its water dynamics complicate instrument-based observations. Meanwhile, communities of living organisms can serve as indicators of environmental heterogeneity. This study aimed to analyze the spatial variability of fish assemblage organisation in the Mekong Delta for use as an indicator of salt water intrusion. The composition of fish assemblages in different parts of the delta were determined by midwater trawl catches during January and April 2021. A total of ~15 thousand individual fish from 74 trawl hauls were captured and analyzed. The null hypothesis was that the fish assemblages in the Mekong Delta are represented by three taxonomic complexes that are localized in the upper course (freshwater), the lower course (brackish) and the middle course (zone of the contact of the fresh and brackish waters) of the delta. The taxonomic composition of the freshwater complex is the most poor and is represented by 9 families. Meanwhile, marginal (the contact zone) and brackish complexes include 26 and 23 families, respectively. Specimens of families Cobitidae, Eleotridae, Plotosidae and Siluridae that are only found in the zone of contact of fresh and brackish waters could be considered as indicator species of its position. The actual boundaries of the brackish and freshwater complexes were determined and the distance from them to the marine delta edge equals 34 and 78 km, respectively. Assessment of the salinity values that correspond to the complex boundaries is a task for future investigation. The position of the boundaries of freshwater and brackish fish taxonomic complexes has a biological basis and could be used as an indicator of salt water intrusion into the Mekong Delta.

Study on the Parameters of Strengthening Soft Surrounding Rock by Electric Pulse Grouting in the Mining Face

As an effective measure for the rapid fracturing of coal and rock, electric pulse fracture technology has been successfully applied in oil extraction and natural gas discharge. Using the electric pulse fracture mechanism, this technology can be applied to grouting reinforcement to improve the infiltration efficiency of grouting. In this study, we used a numerical simulation method to establish numerical models with different electric pulse peak pressures, different grouting times and different drilling spacing conditions Through numerical simulation studies, we found that the influence range of grouting reinforcement grows with the increased maximum pressure generated by the electrical pulse. The most economical and reasonable electric pulse parameter setting is 5 MPa for static grouting pressure and 100 MPa for peak electric pulse pressure. The best grouting time to keep pressure in the borehole is determined as 9 h, and the best borehole interval is 10 m. In addition, through the treatment of the soft roof of the Caojiashan coal mine, we also found that the reinforcement sample within the grouting reinforcement range had a compressive strength of more than 1.1 MPa; after each grouting reinforcement was completed, the hydraulic bracket could advance 12 m each time, which shows that the electric pulse grouting reinforcement technology has an obvious effect on the treatment of soft roof slab.

Modeling the variable transmission rate and various discharges on the spread of Malaria

&lt;abstract&gt;&lt;p&gt;Natural and household discharges are the natural breeding grounds of various mosquito species, including female &lt;italic&gt;Anopheles&lt;/italic&gt; mosquitoes, which transmit the &lt;italic&gt;Plasmodium&lt;/italic&gt; parasite, causing the spread of the life-threatening disease malaria. Apart from that, population migrations also have a substantial impact on malaria transmission, claiming about half a million lives every year around the world. To assess the effects of the cumulative density of households and other natural discharges, and emigration-dependent interaction rates on the dissemination of the vector-borne infectious disease malaria, we propose and analyze a non-linear mathematical model. The model comprises five dependent variables, namely, the density of the susceptible human population, the density of the infective human population, the density of the susceptible female &lt;italic&gt;Anopheles&lt;/italic&gt; mosquito population, the density of the infective mosquito population and cumulative density of household and other natural discharges. In the model, the density of the mosquito population is supposed to follow logistic growth, whose intrinsic growth rate is a linear function of the cumulative density of household and other natural discharges. The nonlinear model is analyzed by using the stability theory of differential equations, numerical simulations and sensitivity analysis. The analysis shows that an increase in non-emigrating population causes increased incidence of malaria. It is also found that an increase in household and other natural discharges accelerates the occurrence of malaria. A basic differential sensitivity analysis is carried out to assess the sensitivity of model solutions with respect to key parameters. The model's numerical simulations demonstrate the analytical findings.&lt;/p&gt;&lt;/abstract&gt;

Development and external validation of automated ICD-10 coding from discharge summaries using deep learning approaches

ObjectivesTo develop an automated international classification of diseases (ICD) coding tool using natural language processing (NLP) and discharge summary texts from Thailand. Materials and methodsThe development phase included 15,329 discharge summaries from Ramathibodi Hospital from January 2015 to December 2020. The external validation phase included Medical Information Mart for Intensive Care III (MIMIC-III) data. Three algorithms were developed: naïve Bayes with term frequency-inverse document frequency (NB-TF-IDF), convolutional neural network with neural word embedding (CNN-NWE), and CNN with PubMedBERT (CNN-PubMedBERT). In addition, two state-of-the-art models were also considered; convolutional attention for multi-label classification (CAML) and pretrained language models for automatic ICD coding (PLM-ICD). ResultsThe CNN-PubMedBERT model provided average micro- and macro-area under precision-recall curve (AUPRC) of 0.6605 and 0.5538, which outperformed CNN-NWE (0.6528 and 0.5564), NB-TF-IDF (0.4441 and 0.3562), and CAML (0.6257 and 0.4964), with corresponding differences of (0.0077 and −0.0026), (0.2164 and 0.1976), and (0.0348 and 0.0574), respectively. However, CNN-PubMedBERT performed less well relative to PLM-ICD, with corresponding AUPRCs of 0.7202 and 0.5865. The CNN-PubMedBERT model was externally validated using two subsets of MIMIC-III; MIMIC-ICD-10, and MIMIC-ICD-9 datasets, which contained 40,923 and 31,196 discharge summaries. The average micro-AUPRCs were 0.3745, 0.6878, and 0.6699, corresponding to directly predictive MIMIC-ICD-10, MIMIC-ICD-10 fine-tuning, and MIMIC-ICD-9 fine-tuning approaches; the average macro-AUPRCs for the corresponding models were 0.2819, 0.4219 and 0.5377, respectively. DiscussionCNN-PubMedBERT performed second-best to PLM-ICD, with considerable variation observed between average micro- and macro-AUPRC, especially for external validation, generally indicating good overall prediction but limited predictive value for small sample sizes. External validation in a US cohort demonstrated a higher level of model prediction performance. ConclusionBoth PLM-ICD and CNN-PubMedBERT models may provide useful tools for automated ICD-10 coding. Nevertheless, further evaluation and validation within Thai and Asian healthcare systems may prove more informative for clinical application.

Drilling boreholes in sulphureous groundwater areas: elements of some case studies in Portugal

In Portugal there is a special market niche, which is the medical spa sector. These are supplied by special groundwater, being the sulphureous type water, the most frequent water in this activity. These waters essentially have a long geohydraulic circuit, associated to granite massifs, in confined to semi-confined aquifer systems of the fissural type, and natural discharge sites are often associated with structurally very complex areas, with faults sometimes of great thickness, that lead to sudden variations, from very fresh rock to clay. However, this situation is very favourable to unexpected collapses of the borehole under construction, with terrible problems to overcome, sometimes leading to involuntary deviations in the spatial position of the drilling in progress. On the other hand, because one of the current solutions is the use of cementations, associated with re-drilling, there is also the problem, of the difficulties of cement grouts in a common situation, not gaining strength, due to the chemical composition of sulphureous groundwater. It should be noted that these aquifer systems have the potential to provide natural hot water, when the boreholes reach great depths and can leverage geothermal uses, at the same time as uses in medical spas. Therefore, it is necessary to know these aquifer systems well, to lead to more efficient projects in the future. Therefore, in that sense, after presenting the typical chemical composition of the sulphureous groundwaters understudy, the experiences acquired in the drilling of some boreholes in Portugal, namely in the Carvalhal Medical Spa, Longroiva Medical Spa, Águas do Graben, Unhais da Serra Medical Spa, and the new mineral water of Granjal (Santa Comba Dão), are briefly presented. The comparison of the objectives defined at the beginning with the results obtained is generically presented, namely the depth of drilling, giving emphasis to the problems of collapse of the walls of the boreholes, cementing, additives, among others. At last, some final notes are presented in the sense that the drillings in this type of hydrogeological systems, in the future come to be increasingly efficient and reach greater depth, not only to acquire water with quality freer of interferences with fluids of superficial aquifers, but also, in the sense of reaching temperatures that make the use of geothermal energy viable.