Balance Components Research Articles

Design and Implementation of a Cost-Effective, Safe, and Precise Lean-Rich Generating System for NOX Storage Reduction Catalyst Evaluation: Performance Analysis, Statistical Modeling, and Multiple Response Optimization – A Guideline for Future Research and Application

Mixing is a critical factor in chemical reaction engineering, particularly in the development of new catalysts for pollutant removal, such as NOx storage reduction catalysts. Comprehensive performance evaluation in laboratory experiments requires high-quality test gases. Several techniques have been developed for generating these gases, each with specific advantages and limitations. This research presents a simple, safe, and cost-effective gas generation system for laboratory applications, including evaluating adsorbents and catalysts, particularly NOx storage reduction catalysts, and for toxicological studies using precise dynamic methods like gas stream mixing and evaporation. Components of the dynamic system—including gas cylinders, connections, mixing chambers, rotameters, the quartz reactor with preheating chamber, bubbler systems, and tubular heaters—are comprehensively described. Statistical modeling and optimization were employed to determine the optimal operating conditions. The optimal conditions were identified as NO (924 ppm), O₂ (15%), CO (9999 ppm), and a space velocity of 105,921 h⁻¹. Additionally, the system's ability to generate various mixtures of gases (NO, O₂, and CO) and vapors (toluene and water) was assessed. The system was further evaluated under fan-on and fan-off modes to assess its performance under varying turbulent conditions. A detailed analysis was performed to determine the relative errors, time to reach steady-state conditions, and actual concentrations produced under different expected concentrations (NO: 100-200 ppm, O₂: 3-15%, CO: 500-10000 ppm, toluene: 64-8999 ppm, relative humidity: 0.14-22.69%), space velocity (70,000-140,000 h⁻¹), bubbler flow rates (10-600 mL/min), and saturator temperatures (5-20°C). Fundamental equations for calculating conversion, selectivity, and yield of a component of interest, carbon-messing, and carbon balance in the mixture are also provided.

Associations between Sleep, Energy Balance and Obesity Markers over 6 Months in Black Emerging Adults - Pilot Study Findings from the Sleep, Health Outcomes and Body Weight (SHOW) Study.

Insufficient sleep (short sleep duration and poor sleep quality) is associated with obesity risk. Emerging adults (ages 18-28 years) have a greater risk of excess weight gain and insufficient sleep, and these risks are higher in Black individuals. Using a measurement burst design, we assessed associations between sleep with energy balance components and obesity marker changes over 6 months in 15 Black emerging adults (12 females; age 21±2.5 years; body mass index 25.7±4.5 kg/m2; body fat 25.8±11.9%). Since our sample was predominantly female (80%), we repeated our analyses for females only. Participants completed the following measurements at baseline (BLN) and 6 months later (6MO): 7 days of actigraphy-based sleep and physical activity energy expenditure (EE) and 2 nights of in-home polysomnography-based sleep; resting EE and thermic effect of food with indirect calorimetry; ad libitum energy intake (EI) via self-reported methods over 4 days and directly measured over 3 days with provided meals. Body weight (2.6 kg, p=0.01) and waist circumference (2.4 cm, p=0.03) increased from BLN to 6MO. Changes in actigraphy-based sleep duration were associated with changes in body weight (β=0.03, Standard error (SE)=0.02, p=0.04) and fat mass (β=0.07, SE=0.03 p=0.03) in females only. Greater rapid eye movement sleep duration was associated with increases in resting EE (β=2.24, SE=0.84, p=0.02). Greater slow-wave sleep was associated with increases in self-reported EI (β=18.34, SE=4.7, p<0.01). Sleep may impact components of energy balance and risk of weight gain in Black emerging adults. Additional research is needed to confirm our pilot findings.

ENERGY ASPECTS OF CONILON COFFEE DEVELOPMENT IN NORTHERN FLUMINENSE. PART 2 - ENERGY BALANCE

Conilon coffee represents a large portion of Brazilian coffee production, and it is essential to understand how the crop relates to the energy available in the environment. Therefore, this study sought to determine the components of the energy balance of the Conilon coffee crop in the North Fluminense region during seven harvests. The experiment was conducted in a crop field in the area belonging to the Darcy Ribeiro State University of North Fluminense, in Campos dos Goytacazes, RJ, which contains a micrometeorological station that monitored environmental data between June 2015 and May 2022. Using this information, the energy balance was performed using the Bowen ratio method, which made it possible to determine the crop evapotranspiration (ETc), the reference evapotranspiration (ET0), and the crop coefficient (Kc). The Bowen ratio energy balance method performed satisfactorily and indicated that 66% of Rn was converted to LE, 24% to H and 10% to G. The average crop evapotranspiration was 3.81 mm.day-1 and the average Kc per harvest showed an increasing trend throughout the experiment and ranged from 0.82 to 0.92. Conilon coffee presented an average productivity of 3.43 t.ha-1 (57.16 sc.ha-1) and it was concluded that an average of 0.08 g per MJ of net energy was produced.

A methodology for computing the thermal balance and energy consumption of autoclaves during steaming of wood

ABSTRACT A methodology for computing the thermal balance and energy consumption of autoclaves during steaming of wood has been presented. With the help of own non-stationary model, the durations of all stages of steaming regimes of beech prisms intended for veneer production with cross- section dimensions of 0.3 × 0.3 m, initial temperature 0 °C, and moisture content 0.4, 0.6, and 0.8 kg·kg−1 were determined at maximum operating temperature in the autoclave equal to 130 °C. With the determined prism steaming durations, using a proposed steady-state model, the total energy required to carry out the entire steaming process in an autoclave with an internal diameter of 2.4 m, a cylinder length of 9.0 m and a degree of filling with prisms 30%, 40% and 50% and also the required for each of the individual components of the thermal balance are calculated. It was found that the total energy consumption of the autoclave increases from 82 to 113 kWh·m−3 when the moisture content of the prisms increases from 0.4 to 0.8 kg·kg−1 at autoclave filling degree of 40%. The methodology can be applied to compute thermal balances of different autoclaves during steaming of wood to any desired final temperature required for their mechanical processing.

Innovative management strategies for groundwater logging in Aswan city and maximization of its benefits using modeling techniques

Groundwater levels vary from region to another and sometimes in different zones in the same country due to different boundary conditions and extraction rates. Therefore, understanding intricate aquifer systems and predicting how they will react to hydrological changes require the use of groundwater models. In Egypt, the groundwater levels in the Nile Delta aquifer decrease causing problems to the delta ecosystem while it is rising in Aswan area due to the presence of Nasser Lake causing several damages to the city’s buildings and infrastructures. In order to maximize its benefits and lessen the harm brought on by inadequate groundwater management in the city of Aswan, the height of the groundwater level in that city was examined, appraised, and groundwater management scenarios were established in this study. To achieve the objectives of the study, a simulation of Aswan aquifer’s groundwater system is built based on a quasi-three-dimensional transient groundwater flow model using MODFLOW. The model was calibrated and verified. Four management scenarios are tested. The fifth scenario, in this scenario, the four scenarios combined together at the same time and with the same conditions and ratios were proposed to be implemented. The results of the proposal to implement the four scenarios together showed that the rates of decline in groundwater levels in the last stage will be 12.44%. The study results reveal that a better understanding of the simulated long-term average spatial distribution of water balance components is useful for managing and planning the available water resources in the Aswan aquifer.

Quantification of the Effect of Soil and Biophysical Parameters on Water Balance Modelling Using SWAT+ in Forested Catchments

ABSTRACTAccurate simulation of water balance components is crucial for effective water and land management practices. The performance of process‐based hydrological models relies on the accurate determination of input variables. The objective of this study is to quantify the magnitude of the effect of soil properties (depth and texture) and biophysical parameters on water balance simulation for a forested catchment using the Soil and Water Assessment Tool (SWAT+). Simulations were carried out for a baseline scenario using the default soil inputs, followed by extending the soil profile depth up to 15 m under three different rainfall scenarios. Sensitivity analysis of model outputs was performed using the SENSitivity ANalysis (SENSAN) programme of the Parameter ESTimation (PEST) suite, coupled with SWAT+. The results showed that increasing soil profile depth to 15 m led to around 50% increase in water yield, and around 20% reduction in percolation with slight variations across the three rainfall scenarios. Evapotranspiration rates were slightly increased in deeper soil profiles. The sensitivity of evapotranspiration, surface runoff, and percolation to LAI‐related biophysical parameters was pronounced, highlighting the need to include such parameters in SWAT+ model calibration. The water uptake from deeper soil layers by deep roots, even in rocky substrates, as documented in the literature, is not adequately captured by the SWAT+ model. Our work showed that in general, developing local soil databases with detailed information on deeper layers is needed, to improve the accuracy and reliability of hydrological models in predicting water fluxes, thereby supporting informed water resources management decisions.

Unlocking the Work–Life Equation: Critical Analysis of Telework Factors for Optimal Balance in the IT/ITES Sector

In the contemporary corporate landscape, the notions of telework, job engagement and work–life balance have emerged as the most compelling concepts. These concepts have been found to significantly enhance employee performance and provide organizations with a strategic competitive edge. Recognizing the relevance of these considerations to the working world, the current study addresses the gap in the literature on telework and work–life balance in the Indian context. The present study makes a valuable contribution to the existing literature on flexible work arrangements, including flexible scheduling, family obligations and job commitment. The study aims to fill a gap in the existing literature by exploring the relationship between telework and work–life balance in the Indian context. While some research is available on telework and work–life balance, there is a lack of specific studies focusing on the Indian context. This study recognizes the importance of understanding the unique cultural and organizational factors that may influence telework and work–life balance in India. Also, the information technology (IT) and IT-enabled services (ITES) industries are well-positioned to maintain their use of telework as a competitive advantage as the globe gets past the pandemic’s initial effects. These industries can strengthen their competitiveness, spur innovation and guarantee long-term success in a global economy driven by digitalization by incorporating remote labour into their fundamental operational plans. IT and ITES businesses have a chance to reimagine the future of work in the post-COVID age by establishing new benchmarks for adaptability, productivity and resilience. This analytical study adopts a cross-sectional time horizon and focuses on individual employees within the IT/ITES sector. The study employed a survey methodology, utilizing a questionnaire developed by the author to collect data. A total of 217 employees participated in the study, with a convenient sampling technique being utilized to ensure a representative sample. The data were then analyzed further with an exploratory factor analysis (EFA). The study identified telework, work facilitator, working situations and job engagement as significant constructs in predicting work–life balance. Implications for research and practice are discussed. This study provides academics with useful insights for theory formation and verification of telework, work–life balance and job engagement. Four key factors were identified through the utilization of EFA: Telework, work facilitators, working situations and job engagement. The aforementioned factors offer significant insights into the fundamental dimensions that influence the work–life balance within this industry. The present study incorporates diverse work arrangements, such as adaptable working hours and telecommuting alternatives, alongside conducive organizational cultures and policies that prioritize family support. The identification of work facilitators as a distinct factor underscores the significance of organizational support in establishing an environment that empowers workers to effectively harmonize their professional and personal obligations. The present study’s results indicate that gender may not be a decisive factor in shaping telework, work facilitators, working situations or job engagement in the IT/ITES industry, since there is no discernible connection between gender and these variables. Because the study was restricted to the IT/ITES industry, its conclusions might not be easily applied to other industries. Additionally, as the investigation relied on self-reported data, it may have been impacted by biases and a tendency to behave in a way that appears appealing to others. Prospective research endeavours could investigate the relationship between gender and work–life balance components in a variety of contexts and examine additional demographic characteristics that may influence these elements. The study’s findings could potentially provide valuable information for both employers and employees in the IT/ITES sector. Employers may gain insights into the factors that contribute to work–life balance disparities, enabling them to implement policies and practices that support healthier work–life integration for their employees. Employees, on the other hand, may benefit from a better understanding of how their demographic characteristics intersect with work–life balance factors, allowing them to make informed decisions about their career and personal life. This study captures the potential of telework in emerging economies for increasing job engagement. A unique and modern insight into how telework affects the technology space is what makes the work stand out from the static framework in the literature. How telework and its variables affect work–life balance and job engagement of the employees and how the organizations have a positive impact on productivity, is the novel factor in the study.

Carbon dioxide and evapotranspiration fluxes in an urban area of Krakow, Poland

AbstractUrban areas play an essential role in the global carbon balance, being responsible for more than 70% of anthropogenic carbon emissions, entering the atmosphere mainly in the form of carbon dioxide (CO2). Another crucial component of the carbon balance of the urban atmosphere is CO2 exchange with the biosphere, expressed in both emission and absorption fluxes. The biosphere component of the net CO2 flux is inseparably linked to the water (H2O) balance due to evapotranspiration. This article presents an estimation of CO2 and H2O net fluxes based on eddy covariance (EC) tower measurements and in‐depth analysis of its temporal and spatial variability for a typical urban site at mid‐latitude of the northern hemisphere. The source area was divided into two sectors, one representing dense urban development with sources of CO2 from traffic and households, and the second containing predominantly recreation and sports areas. Temporal variability analysis of evapotranspiration showed a clear seasonal cycle closely correlated with incoming radiation and air temperature, with the seasonal mean ranging from 0.4 mm·day−1 in winter to 1.6 mm·day−1 in summer. As a result of similar green coverage between the urban and green sectors, spatial variability was statistically insignificant. The net CO2 flux over a seasonal cycle was less pronounced for the total source area with a mean of 5.0 g C·m−2·day−1 in summer and 7.5 g C·m−2·day−1 in winter. However, significant variations between urban and green sectors were observed with the highest seasonal mean difference of 4.5 g C·m−2·day−1 in winter. The results confirm that while on the local, short time‐scale urban vegetation has a potential to mitigate the emissions, it is not able to offset them.

The decline in tropical land carbon sink drives high atmospheric CO2 growth rate in 2023

Abstract Atmospheric CO2 growth rate (CGR), reflecting the carbon balance between anthropogenic emissions and net uptake from land and ocean, largely determines the magnitude and speed of global warming. CGR at Mauna Loa Baseline Observatory reached record high in 2023. Here we quantified major components of global carbon balance for 2023, by developing a framework which integrated fossil fuel CO2 emissions data, an atmospheric inversion from Global ObservatioN-based system for monitoring Greenhouse GAses (GONGGA) with two artificial intelligence (AI) models derived from dynamic global vegetation models. We attributed the record high CGR increase in 2023 compared to 2022 primarily to the large decline in land carbon sink (1803 ± 197 TgC year−1), with minor contributions from a small reduction in ocean carbon sink (184 TgC year−1) and a slight increase in fossil fuel emissions (24 TgC year−1). At least 78% of the global decline in land carbon sink was contributed by the decline in tropical sink, with GONGGA inversion (1354 TgC year−1) and AI simulations (1578 ± 666 TgC year−1) showing similar declines in the tropics. We further linked this tropical decline to the detrimental impact of El Niño-induced anomalous warming and drying on vegetation productivity in water-limited Sahel and southern Africa. Our successful attribution of CGR increase within the framework combining atmospheric inversion with AI simulations enabled near-real-time tracking of the global carbon budget which had a one-year reporting lag.

How have atmospheric components of the local water cycle changed around the abrupt climatic shift over France?

The significant increase in surface air temperature experienced by Western Europe over the last few decades has resulted in an abrupt warming in France, around 1987/1988 years. This climatic shift impacted hydrological cycle, particularly by reducing runoff in spring and summer. Evapotranspiration and precipitation have been identified as the main drivers of climatic water balance. But the impact of the 1987/1988 climatic shift on local water cycle over France has not been quantified yet. This study tries to assess the consequences of this rapid warming on the main climatic components of local water cycle. Climate variables linked to the water cycle extracted from a reanalysed observed climate database are analysed using robust Bayesian change points detection and mean comparison techniques. After the abrupt rise in surface air temperature and surface solar radiation, water demand increases significantly on almost the entire French territory in spring, summer and autumn. Our results show that, from March to May, the vegetation cover is able to respond to this increase by drawing from the soil water reservoirs. But in summer, most of the territory is facing a significant rise in water constraint (i.e. difference between potential and actual evapotranspiration), extending on the last decade over autumn. In spring and summer, the increase in potential evapotranspiration is the main driver of the intensification of water constraint. In the beginning of autumn, longer dry spell also plays a major role in the lengthening of periods of water constraint. This innovative study highlights the specific impact of a climatic shift on the main components of the atmospheric water balance at regional and local scale. As the observed changes in climate hazard linked to water cycle affect growth cycle of the majority of the vegetation covers and crops, this could lead to a worsening of hydric stress events. As such climatic shifts are expected to happen again in the future, their impacts on the local water cycle represent a major issue for natural terrestrial ecosystems as well as for agriculture.

Evaluating precipitation corrections to enhance high-alpine hydrological modeling

Gridded meteorological data products often fall short in accurately capturing the amount of precipitation and its patterns in regions characterized by high elevations and complex topography. However, realistic precipitation data is crucial for high-alpine hydrological modeling. To address these discrepancies, we analyze possible corrections for solid, liquid and total precipitation of the 1 km2 gridded meteorological INCA-product in the high-alpine catchment of the Kölnbrein hydropower reservoir operated by VERBUND Hydro Power GmbH in the Malta Valley in Austria. By leveraging information from a stereo-satellite-derived snow depth map with physically-based snowpack modeling with Alpine3D, we quantitatively adjust and spatially redistribute solid precipitation, complemented by a multiplicative, stepwise correction model for liquid precipitation. We compare and evaluate five approaches using the hydrological COSERO model to our a) baseline simulation with no corrections on INCA in contrast of correcting, b) the amount and distribution of solely solid precipitation, c) the amount of liquid and solid precipitation, d) the amount of liquid and solid precipitation and the spatial distribution of the latter, e) precipitation inversely by the inflow bias, and f) calibrating the precipitation correction factor. In evaluating these strategies to improve the accuracy of reservoir inflow predictions, we found that separately correcting solid and liquid precipitation yielded the best results (c &d), with a substantial increase of up to 65% over the study period (1.10.2015–30.9.2023), while the other correction variants ranged between 42 and 52%. The inflow predictions by COSERO showed an increase in Nash-Sutcliffe Efficiency (NSE) by 17% and in Kling-Gupta Efficiency by 57% and 59% for variants c and d, respectively, along with an almost complete elimination of model bias. The higher KGE values observed for variant d compared to c during spring, summer, and fall suggest that a more realistic snow distribution enhances the simulation of snowmelt-driven runoff dynamics. In contrast, using a global (i.e., spatially homogeneous) and uniform (i.e., not distinguishing between liquid and solid precipitation phase) correction factor, inversely derived from the inflow bias (e), or solely correcting solid precipitation (b), demonstrated less performance, with a KGE increase of 47% and 49%, respectively, compared to 59% for variant d. Conversely, the calibration of the global and uniform correction factor (f) resulted in significant performance metric improvements (17% NSE, 60% KGE and 90% pBias), similar to variant d, however also led to unrealistic simulations of evapotranspiration, sublimation and glacier net runoff. The simulated water balance components – evapotranspiration and sublimation, as well as glacier runoff – in variant d were deemed plausible based on our comparison with additional simulations using Alpine3D, as well as findings from other high-alpine catchments in Austria reported in the literature. Overall, our results underscore the importance of applying a dual correction strategy for both liquid and solid precipitation, particularly when significant deficiencies are present in meteorological datasets, and suggest that such corrections should be supplemented by a comprehensive analysis of the simulated high-alpine water balance components.

Effects of overnight-fasted versus fed-state exercise on the components of energy balance and interstitial glucose across four days in healthy adults

Exercise is an essential component of body mass management interventions. Overnight-fasted exercise (FASTex) acutely enhances fat oxidation compared with fed exercise (FEDex). However, consistent FASTex training does not typically further enhance body mass loss, suggesting the induction of energy compensation responses. The present study aimed to test the effects of FASTex or FEDex on the components of energy balance (i.e., energy intake (EI), energy expenditure (EE), and appetite) and interstitial glucose metrics across four days. MethodsTwelve (10 men, 2 women) healthy, physically active participants (age 22.6 + 1.2 years (mean ± SD); BMI 22.5 ± 2.8 kg ⋅ m−2) were studied twice, across four days, after a 75-min run either FASTex or FEDex. Daily EI was obtained after subtracting leftovers from the provided food. Daily fasting appetite was measured by visual analogue scales. Activity- and total- EE (AEE & TEE, respectively) were estimated by combining heart rate and accelerometry. Continuous glucose monitoring was used to capture daily interstitial glucose metrics and Likert scales were utilised to quantify fatigue, stress, sleep quality, and muscle soreness levels. ResultsNo differences between conditions were observed for EI (FASTex = 15.0 ± 0.1 vs FEDex = 15.0 ± 0.4 MJ⋅day−1; p = 0.865), AEE (FASTex = 7.6 ± 1.1 vs FEDex 7.8 ± 1.3 MJ⋅day−1; p = 0.223) and TEE (FASTex = 15.9 ± 3.4 vs 14.9 ± 4.5 MJ⋅day−1; p = 0.136). Additionally, no condition effects for appetite (p > 0.05) and interstitial glucose (p = 0.074) were observed. ConclusionFASTex did not differ from FEDex in the response of components of energy balance or interstitial glucose across four days, suggesting that both exercise approaches could be used interchangeably.

Coupled simulation of percolation and evapotranspiration in semi-mobile and semi-fixed dunes

Accurately describing the important components of the water balance, such as precipitation (P), deep percolation (D), and evapotranspiration (ET) and their relationships is crucial for understanding the water cycle and eco-hydrological processes in arid and semi-arid regions. This study coupled the dual crop coefficient model (Dualkc) with the HYDRUS-1D model to simulate D and ET processes in the semi-mobile and semi-fixed dune ecosystem in China’s Horqin Sandy Land during the growing seasons from 2015 to 2022. The results indicated that the improved HYDRUS-1D model achieved high simulation accuracy at a daily scale, with the R2 of 0.83, RMSE of 0.392, NSE of 0.714, and b of 0.828, representing increases of 15.27%, 20.16%, 16.01%, and 5.6%, respectively, compared to the original model. ET and D constituted the primary water dissipation processes in semi-mobile and semi-fixed dunes, accounting for 97% to 99% of P during the growing season. The evaporative ratio (ET/P) ranged from 46.7% to 79.3%, averaging 65.67% over multiple years, and the deep percolation ratio (D/P) varied between 16.1% and 53%, averaging 31.02%. The distribution of precipitation events, soil water content, and vegetation conditions are critical factors affecting ET and D in arid and semi-arid dune ecosystems. This study is of great significance for a deep understanding of the eco-hydrological processes in the dune ecosystem, and it can provide important support in developing water management strategies in the desertification region.

The Relationship between Components of Postural Control and Locomotive Syndrome in Older Adults.

Locomotive Syndrome (LS), a condition related to impaired mobility, is influenced by balance control, which comprises six components. Deficiencies in these components can lead to reduced mobility and decreased quality of life. This study aimed to evaluate the relationship between the components of postural control and LS in older adults using the Brief-BESTest. Therefore, this cross-sectional study involved 122 elderly participants from Tha Sala District, Nakhon Si Thammarat Province, both with and without LS. Participants underwent assessments using the Instrumental Activities of Daily Living (IADL) assessment, the Thai Mental State Examination (TMSE), the Two-Step Test, and the Brief-BESTest. The Brief-BESTest covers six balance components: Biomechanical Constraints, Stability Limits, Anticipatory Postural Adjustments, Postural Responses, Sensory Orientation, and Stability in Gait. Descriptive statistics were used to summarize participant characteristics, and Chi-square tests were conducted to examine the relationship between each balance component and LS. Cramer's V was used to assess the strength of the relationships. The results showed the average age of the sample was 67.67 ± 6.01 years with 85.20 percent female and 14.80 percent male. There were significant relationships between LS and three balance components: Biomechanical Constraints (Chi-square = 5.35, p = 0.021, Cramer's V = 0.209), Stability Limits (Chi-square = 5.00, p = 0.025, Cramer's V = 0.204), and Anticipatory Postural Adjustments (left: Chi-square = 4.12, p = 0.042, Cramer's V = 0.213; right: Chi-square = 5.50, p = 0.019, Cramer's V = 0.213). No significant associations were found for Reactive Postural Response, Sensory Orientation, and Stability in Gait. These findings suggest that targeted interventions focusing on specific balance components consist of Biomechanical Constraints, Stability Limits, and Anticipatory Postural Adjustments could help reduce the risk of LS in older adults.

Fully automated simplification of urban drainage models on a city scale

ABSTRACT The article presents an innovative method for simplifying urban drainage models. This approach strategically reduces complexity while preserving accuracy in large-scale, high-resolution models such as those of the city of Graz. It involves the selective removal and aggregation of sewer network elements like subcatchments and conduits, ensuring vital features like storage nodes and flow controls remain intact for precise simulations. Despite significant reductions in model components, the simplified version maintains high accuracy in hydrological and hydraulic aspects, including water balance components like infiltration loss, surface runoff, and external outflow. The method proves equally effective across both land cover and sewer shed-based models, offering computational efficiencies that speed-up processing by 20–45 times for the study site. This is particularly beneficial for rapid decision-making and resource optimization in urban planning. The model also adeptly predicts flood events, especially from larger, infrequent rainfall, although an overly restrictive flow capacity can refine flood predictions at the expense of other flow characteristics. Ultimately, this streamlined approach allows for the quick creation of simplified, yet accurate, models from high-resolution city-scale hydrodynamic data or digital twins, facilitating efficient and timely analyses in urban drainage management.

Application of the Soil and Water Assessment Tool (SWAT) Model for hydrological modelling in the Upper Oum Er Rbia watershed (Middle Atlas, Morocco)

Abstract In the study assessing the impact of global change on hydrosystems, particularly water resources, calibrated and validated tools are deemed crucial for accurate representation of the area’s characteristics. The Soil and Water Assessment Tool “SWAT” model is identified through literature review as well-suited for evaluating changes in land use and climate effects on water balance components. Applied to the Upper Oum Er Rbia watershed and its sub-basins, namely Oum Er Rbia, Srou, and Ouaoumana, the SWAT model demonstrates its effectiveness over the 1982-2019 period. Employing the sequential uncertainty adjustment method (SUFI-2) in SWAT-CUP software for calibration and validation, the model achieves good performance in simulating river flows. Statistical tests, including “R²,” “NSE,” “PBIAS,” and “RSR,” reveal consistent accuracy across various stations. The positive outcomes affirm the SWAT model’s operational capability for diagnostic assessments, risk evaluation, adaptation measures, and potential future projections in these three sub-basins.

Lower grass stomatal conductance under elevated CO2 can decrease transpiration and evapotranspiration rates despite carbon fertilization.

Anthropogenic increase in carbon dioxide (CO2) affects plant physiology. Plant responses to elevated CO2 typically include: (1) enhanced photosynthesis and increased primary productivity due to carbon fertilization and (2) suppression of leaf transpiration due to CO2-driven decrease in stomatal conductance. The combined effect of these responses on the total plant transpiration and on evapotranspiration (ET) has a wide range of implications on local, regional, and global hydrological cycles, and thus needs to be better understood. Here, we investigated the net effect of CO2-driven perennial ryegrass (Lolium perenne) physiological responses on transpiration and evapotranspiration by integrating physiological and hydrological (water budget) methods, under a controlled environment. Measurements of the net photosynthetic rate, stomatal conductance, transpiration rate, leaf mass per area, aboveground biomass, and water balance components were recorded. Measured variables under elevated CO2 were compared with those of ambient CO2. As expected, our results show that elevated CO2 significantly decreases whole-plant transpiration rates (38% lower in the final week) which is a result of lower stomatal conductance (57% lower in the final week) despite a slight increase in aboveground biomass. Additionally, there was an overall decline in evapotranspiration (ET) under elevated CO2, indicating the impact of CO2-mediated suppression of transpiration on the overall water balance. Although studies with larger sample sizes are needed for more robust conclusions, our findings have significant implications for global environmental change. Reductions in ET from ryegrass-dominated grasslands and pastures could increase soil moisture and groundwater recharge, potentially leading to increased surface runoff and flooding.

Evaluating water balance components in a tropical ecological zone under land use changes

Water availability for domestic, institutional, and agricultural production is threatened by the continuous change in land use land cover (LULC). These changes in LULC features affect the dynamics of the hydrological processes such as surface runoff, infiltration, and evapotranspiration, resulting in variations in water availability especially, for human consumption and crop yield. Therefore, the Soil and Water Assessment Tool (SWAT) hydrological model was deployed to simulate the Pra River Basin (PRB)’s water balance response to changing LULC from 1986 to 2020. Open and closed forests reduced from an area of 11,071 km2 to 5902 km2 and 5125 km2 to 4990 km2 while settlement and cropland increased from 1100 km2 to 2392 km2 and 5303 km2 to 9320 km2 representing an average annual expansion rate of +24.7 km2/yr and +118 km2/yr respectively over the three decades. The growth in settlement and cropland resulted in an upsurge of more than 33 % and 20 % in surface runoff and water yield respectively, but decreases of over 4 % and 17 % in evapotranspiration and baseflow respectively. These changes have resulted in a seasonal increase in surface runoff, baseflow, and evapotranspiration (ET) during the wet season but a decrease during the dry season. The PRB has experienced a dramatic decline in forest areas, chiefly in areas where settlement and farmlands have been expanded. The areas where surface runoff and water yield showed significant upsurge and reduction in ET are the northwestern and southern enclaves of the basin. These findings can aid in effectively planning and managing land use to control the gradually depleting water resources in the basin.

СВЯЗИ МЕЖГОДОВЫХ ВАРИАЦИЙ СРЕДНЕМЕСЯЧНЫХ УРОВНЕЙ КАСПИЯ, А ТАКЖЕ СУММ АТМОСФЕРНЫХ ОСАДКОВ В ЕГО БАССЕЙНЕ И ИХ ИЗМЕНЕНИЯ ПРИ СОВРЕМЕННОМ ПОТЕПЛЕНИИ КЛИМАТА

In the modern period, the level of the Caspian Sea water surface is rapidly decreasing, which creates significant problems for the population and economy of all countries of the Caspian region. Therefore, improvement of the methods for forecasting its further changes is an urgent problem of hydrology, meteorology and ecology. It is generally accepted that the main reasons for the current decline in the Caspian Sea level are the influence of anthropogenic factors and climatic changes on the dynamics of its water balance components. A significant component of the incoming part of this balance is the amount of precipitation falling in the territory of the Caspian basin. One of the methods used for forecasting the Caspian Sea level is multiple regression analysis. The validity of the forecasts obtained with its help depends on the significance of the relationships between the studied process in the future and the factors monitored in the present and in the past that are taken into account in their development. The article assesses the significance of statistical correlations between interannual variations in the average monthly background levels of the Caspian Sea and the dynamics of precipitation amounts in its basin, as well as its changes during the period of modern climate warming. The ERA 5 reanalysis information was used as factual material on precipitation. Information on the levels was obtained from literary sources. It was found that in the period of 1979-2021 the conclusion on the significance of the relationships under consideration was characterized by the reliability of at least 0.95 only if the changes in precipitation amounts corresponded to May. As the time shift between the analyzed process and this factor increases from 0 to 36 months, their correlation remains positive and significant, but slightly weakens. During the period of modern climate warming, the revealed correlation also became weaker, which allows us to doubt its significance even in the near future. There were also identified the Caspian basin areas for which, on the contrary, the considered relationship strengthened during the same period. It implies that the probability of the scenario in which they remain significant in the future is higher than that of other scenarios. Therefore, it is reasonable to take the identified relationships into account when forecasting changes in the average level of the Caspian Sea.

Future Projection of Water Resources of Ruzizi River Basin: What Are the Challenges for Management Strategy?

This study investigates the impact of climate change on hydrological dynamics in the Ruzizi River Basin (RRB) by leveraging a combination of observational historical data and downscaled climate model outputs. The primary objective is to evaluate changes in precipitation, temperature, and water balance components under different climate scenarios. We employed a multi-modal ensemble (MME) approach to enhance the accuracy of climate projections, integrating historical climate data spanning from 1950 to 2014 with downscaled projections for the SSP2-4.5 and SSP5-8.5 scenarios, covering future periods from 2040 to 2100. Our methodology involved calibrating and validating the SWAT model against observed hydrological data to ensure reliable simulations of future climate scenarios. The model’s performance was assessed using metrics such as R2, NSE, KGE, and PBIAS, which closely aligned with recommended standards. Results reveal a significant decline in mean annual precipitation, with reductions of up to 37.86% by mid-century under the SSP5-8.5 scenario. This decline is projected to lead to substantial reductions in surface runoff, evapotranspiration, and water yield, alongside a marked decrease in mean monthly stream flow, critically impacting agricultural, domestic, and ecological water needs. The study underscores the necessity of adaptive water resource management strategies to address these anticipated changes. Key recommendations include implementing a dynamic reservoir operation system, enhancing forecasting tools, and incorporating green infrastructure to maintain water quality, support ecosystem resilience, and ensure sustainable water use in the RRB. This research emphasizes the need for localized strategies to address climate-driven hydrological changes and protect future water resources.