Initial Water Research Articles

Potential Predictability of Two-Year Droughts in the Missouri River Basin

Abstract Potential predictability of 2-yr droughts indicated by low runoff in the consecutive April–September seasons in the upper Missouri River basin (UMRB) and lower Missouri River basin (LMRB) is examined with observed estimates and climate models. The majority of annual runoff is generated in April–September, which is also the main precipitation and evapotranspiration season. Physical features related to low April–September runoff in both UMRB and LMRB include a dry land surface state indicated by low soil moisture, low snowpack indicated by low snow water equivalent, and a wave train across the Pacific–North American region that can be generated internally by the atmosphere or forced by the La Niña phase of El Niño–Southern Oscillation. When present in March, these features increase the risk of low runoff in the following April–September warm seasons. Antecedent low soil moisture significantly increases low runoff risks in each of the following two April–September, as the dry land surfaces decrease runoff efficiency. Initial low snow water equivalent, especially in the Missouri River headwaters of Montana, generates less runoff in the subsequent warm season. La Niña increases the risk of low runoff during the warm seasons by suppressing precipitation via dynamically induced atmospheric circulation anomalies. Model simulations that differ in their radiative forcing suggest that climate change increases the predictability of 2-yr droughts in the Missouri River basin related to La Niña. The relative risk of low runoff in the second April–September following a La Niña event in March is greater in the presence of stronger radiative forcing. Significance Statement Drought spanning consecutive years in the upper Missouri River basin (UMRB) and lower Missouri River basin (LMRB) poses threats to a region whose economy depends on reliable water quantity to support transportation and recreation, adequate water supply for irrigated agriculture, and sufficient streamflow to generate hydroelectric power. We examined physical features in March related to low runoff in the following April–September—low soil moisture, low snow water equivalent, and La Niña events—and examined their effect on the risk of 2-yr drought occurrences. These physical features lead to sustained impacts on the surface water balance. Low snow water equivalent generates less runoff, low soil moisture reduces the runoff efficiency of converting precipitation into runoff, and La Niña inhibits warm-season precipitation and runoff via atmospheric circulation anomalies.

Multiple Heat Recovery System for an Industrial Thermal Peeling Press Machine—Experimental Study with Energy and Economic Analyses

The enhancement of energy systems in industrial zones is attracting the attention of researchers from all over the world. At the same time, optimization and advancement in heat recovery systems are now generating major interest in the energy sector. In this context, the present study suggests a new multiple heat recovery system should be applied to an industrial thermal peeling press machine. The new system consists of multiple sources of energy: the heat excess in the chimney, the exhaust gas of the chimney, and the exhaust gas of the boiler. To proceed with testing the potential of the suggested system, a hydraulic thermal peel press machine in the wood industry undergoes different tests to achieve the best configuration that will enable this machine to reach its operational temperature when heating. Five test configurations are proposed, designed, and applied experimentally on this machine. Many parameters were effective during the experimental tests, such as water flow rate, ambient air temperature, and initial water temperature. It was found that the application of the multiple heat recovery system increases the rate of heating from around 7 °C/min to around 13 °C/min. In terms of energy and economy, the “chimney + boiler only” configuration proved to be the best system to apply during the fall and winter seasons.

Exploration on the Mildew Conditions of Cladosporium asperulatum CY-H1, a Pathogenic Fungus on Tobacco Leaves

Aims: Mildew poses a significant threat to tobacco industry. This study focuses on a strain of Cladosporium asperulatum isolated from moldy tobacco leaves to investigate its growth under different temperature and humidity conditions, aiming to provide a theoretical basis for local prevention and control strategies against this fungus.
 Methodology: Potential fungal strains were obtained from moldy tobacco leaves utilizing isolation techniques and individual colonies were cultured on PDA medium subsequently. Microscopic examination and molecular identification were employed to determine the species of the isolated strains. Isolated strain was initially inoculated with varying spore powder concentrations at water activities of 0.99, 0.95, 0.90, 0.87, 0.83, and 0.77, combined with diverse culture temperatures of 15°C, 20°C, 25°C, 30°C, and 35°C on PDA. The growth of colony area was daily measured by ImageJ software, and spore powder yield was observed after a 7-day incubation period under these specified culture conditions.
 Results: (1) colony area of isolated C. asperulatum CY-H1 has a rising trend with increasing culture time at consistent temperatures. Sporulation exhibited an initial increase followed by a decrease, yet overall demonstrated an upward trajectory. The maximum value was attained at a water activity of 0.95. Under identical water activity, escalating temperatures initially augmented colony area until reaching a maximum at 25°C. Similarly, spore production displayed an initial increase followed by a decrease, with the highest production occurring at 25°C. (2) Varied concentrations of initial spore suspension influenced colony growth differently. A high concentration (initially 106 spores/mL) exhibited an earlier growth trend compared to medium (105 spores/mL) and low concentrations (104 spores/mL). (3) C. asperulatum CY-H1 did not thrive under the culture conditions of 35°C, irrespective of the initial inoculation concentration and water activity.
 Conclusion: C. asperulatum assumes a crucial role as a predominant mold in tobacco storage environments. Effective prevention of fungal mildew in stored tobacco leaves is achieved by maintaining temperatures exceeding 35°C and sustaining water activity below 0.77. These findings highlight the significance of environmental conditions in controlling mold growth during tobacco storage.

Study of the effect of salt deposition on production capacity and storage capacity in underground gas storage

Underground gas storage (UGS) is the most economical and effective means to guarantee stable gas supply. During gas production process, the evaporation of formation water leads to the increase of water content in the gas, and the salinity of the remaining formation water increases. This work applied numerical simulation to analyze the effect of salt deposition on flowing bottomhole pressure, production capacity and storage capacity. The simulation results show that the minimum and maximum pressure of UGS is more likely to be reached during multi-cycle production under the conditions of salt deposition. Under the initial water condition, reservoir drying can improve the gas storage capacity. At the end of the tenth cycle, the storage capacity increases by 1.4%. It is concluded that the study on the impact of formation water evaporation on storage capacity is helpful for the prevention and control of salt formation water in UGS with high salinity.

The Influence About Coupled Initial Water Content and Local Expansion on Mechanical Properties and Deformation of the Tunnel in Mudstone

The Influence About Coupled Initial Water Content and Local Expansion on Mechanical Properties and Deformation of the Tunnel in Mudstone

Experimental Evaluation of Lunar Regolith Settlement Caused by Ice Extraction

Water resources are essential to human exploration in deep space or the establishment of long-term lunar habitation. Ice discovered on the Moon may be useful in future missions to the lunar surface, necessitating the consideration of in situ resource utilization if it is present in sufficient amounts. Extraction of ice can cause the regolith to settle, which can lead to unintended structural damage. Therefore, any settlement resulting from ice extraction should be understood from a geotechnical perspective. This work reports on experimental investigation of the potential settlement caused by the extraction of ice from lunar regolith simulant containing different textures of ice. The KLS-1 simulant was prepared with different water contents and ice textures. Significant settlement occurred in simulant–ice mixtures with initial water contents of 5–10%.

Enhanced hydrophilicity of low melting point polylactic acid by butenediol vinyl alcohol copolymer via melt blending

In order to solve the poor hydrophilicity of low melting point polylactic acid (LMPLA) limiting its application in absorbent sanitary products. LMPLA/butenediol vinyl alcohol copolymer (BVOH) blends with different ratios were manufactured by simple melt blending. The BVOH exhibited good compatibility and dispersity in LMPLA matrix without chemical reaction, and LMPLA/BVOH blends showed sea-island structure. The introduction of BVOH could promote the crystallization of LMPLA and improve the crystallinity, whereas the crystallization of BVOH were limited. Furthermore, the introduction of BVOH could also decrease the thermal stability of LMPLA without affecting its application, but the tensile stress of LMPLA could be significantly increased. The tensile stress of LMPLA/BVOH blends could reach 78.59 MPa (increased by 10.9%) when he BVOH content was 3 wt%. Most importantly, the introduction of BVOH could significantly improve the hydrophilicity of LMPLA. The initial water contact angle decreased from 68.5° to 51.4° with the increase of BVOH content, and the contact angle decreased from 63.7° to 44.6° at 60 s. Moreover, the contact angle change rate of LMPLA/BVOH blends increased with the increase of BVOH content at different contact time, which also indicated adding BVOH could sharply improve the hydrophilicity of LMPLA.

The time validity of Philip's two‐term infiltration equation: An elusive theoretical quantity?

AbstractThe two‐term infiltration equation is commonly used to determine the sorptivity, , and product, , of the dimensionless multiple and saturated soil hydraulic conductivity from cumulative vertical infiltration measurements (L) at times (T). This reduced form of the quasi‐analytical power series solution of Richardson's equation of Philip enjoys a solid physical underpinning but at the expense of a limited time validity. Using simulated infiltration data, Jaiswal et al. have shown this time validity to equal about 2.5 cm of cumulative infiltration. The goals of this work are twofold. First, we investigate the extent to which cumulative infiltration measurements larger than 2.5 cm bias the estimates of and . Second, we investigate the impact of epistemic errors on the inferred time validities and parameters. Partial infiltration curves up to 2.5 cm of cumulative vertical infiltration improve substantially the agreement between actual and least squares estimates of and . But this only holds if the data generating infiltration process follows Richardson's equation and experimental conditions satisfy assumptions of soil homogeneity and a uniform initial water content. Otherwise, autocorrelated cumulative infiltration residuals will bias the least squares estimates of and . Our findings reiterate and reinvigorate earlier conclusions of Haverkamp et al. and show that epistemic errors deteriorate the physical significance of the coefficients of infiltration functions. As a result, the parameters of infiltration functions cannot simply be used in storm water and vadose zone flow models to forecast runoff and recharge at field and landscape scales unless these predictions are accompanied by realistic uncertainty bounds. We conclude that the time validity of Philip's two‐term equation is an elusive theoretical quantity with arbitrary physical meaning.

Physical simulation study on production characteristics and mechanism of connate water in gas reservoirs

The late-stage development of gas reservoirs often encounters the paradox of significant remaining formation pressure coupled with low wellhead pressure, which indicates small drainage volume, low gas production rate, and low recovery efficiency, reducing gas supply and economic benefit. Owing to the lack of experimental research, the reasons behind this contradiction between gas production and producing pressure differential are unclear. The key factors affecting the development outcomes are reservoir permeability and initial water saturation, while the evaluation parameters include gas and water production rates, reservoir pressure, and recovery efficiency. Based on the characteristic properties of typical gas fields, physical simulation experiments of constant-rate gas production are conducted on spliced long cores with average permeabilities of 2.300, 0.486, and 0.046 millidarcy (mD). Furthermore, leveraging the multi-point embedded pressure measurement technique, the pressure drawdown propagations and the macroscopic and microscopic characteristics of connate water production at the initial water saturations of 0%, 20%, 40%, and 55% are investigated. By connate water, we mean water that occurs naturally within the pores of rock. Pre- and post-experiment core weighing and nuclear magnetic resonance testing are performed. In addition to the mercury injection tests, the results indicate that during gas reservoir depletion, connate water primarily stems from macropores and mesopores, with micropores and nanopores capturing water through capillary imbibition. Moreover, lower permeability and higher initial water saturation lead to greater pressure gradients, increased connate water production, and reduced recovery efficiency. Reservoirs with permeabilities below 0.1 mD are significantly affected by connate water, exhibiting steep pressure profiles. Owing to connate water, the near-wellbore pressure quickly decreases, while distant reservoir pressure barely decreases, implying a limited drainage area. To enhance the recovery efficiency, measures like infill drilling and reservoir stimulation are recommended for low-permeability gas reservoirs.

Improving Flash Flood Hydrodynamic Simulations by Integrating Leaf Litter and Interception Processes in Steep-Sloped Natural Watersheds

More frequent high-intensity, short-duration rainfall events increase the risk of flash floods on steeply sloped watersheds. Where measured data are unavailable, numerical models emerge as valuable tools for predicting flash floods. Recent applications of various hydrological and hydrodynamic models to predict overland flow have highlighted the need for improved representations of the complex flow processes that are inherent in flash floods. This study aimed to identify an optimal modeling approach for characterizing leaf litter losses during flash floods. At a gauged watershed in the Hidegvíz Valley in Hungary, a physical-based model was calibrated using two distinct rainfall–runoff events. Two modeling methodologies were implemented, integrating canopy interception and leaf litter storage, to understand their contributions during flash flood events. The results from the model’s calibration demonstrated this approach’s effectiveness in determining the impact of leaf litter on steep-sloped watersheds. Soil parameters can estimate the behavior of leaf litter during flash flood events. In this study, hydraulic conductivity and initial water content emerged as critical factors for effective parametrization. The findings underscore the potential of a hydrodynamic model to explore the relationship between leaf litter and flash flood events, providing a framework for future studies in watershed management and risk-mitigation strategies.

Molecular driving forces for water adsorption in MOF-808: A comparative analysis with UiO-66.

Metal-organic frameworks (MOFs), with their unique porous structures and versatile functionality, have emerged as promising materials for the adsorption, separation, and storage of diverse molecular species. In this study, we investigate water adsorption in MOF-808, a prototypical MOF that shares the same secondary building unit (SBU) as UiO-66, and elucidate how differences in topology and connectivity between the two MOFs influence the adsorption mechanism. To this end, molecular dynamics simulations were performed to calculate several thermodynamic and dynamical properties of water in MOF-808 as a function of relative humidity (RH), from the initial adsorption step to full pore filling. At low RH, the μ3-OH groups of the SBUs form hydrogen bonds with the initial water molecules entering the pores, which triggers the filling of these pores before the μ3-OH groups in other pores become engaged in hydrogen bonding with water molecules. Our analyses indicate that the pores of MOF-808 become filled by water sequentially as the RH increases. A similar mechanism has been reported for water adsorption in UiO-66. Despite this similarity, our study highlights distinct thermodynamic properties and framework characteristics that influence the adsorption process differently in MOF-808 and UiO-66.

An Artificial Neural Network Model for Predicting Initial Water Saturation of Petroleum Reservoirs

Initial Water saturation is the water saturation of a reservoir before production commences. It enables the reservoir engineer to properly estimate the correct volume of Oil or gas reserves and to produce without water. And over the years over estimation or under estimation had caused major changes in the decision making of oil companies. New techniques are developed as technology advances to measure water saturation. These are the most widely used techniques for determining water saturation, nevertheless. Measurements obtained directly from a sealed core, which are more expensive, or calculations made using the Archie equation on sample well logs, which are less expensive. In this Project, Artificial Neural Network (ANN) model is the sole purpose of the modelling. The datasets are gathered, processed, trained, tested and validated.

Research on the influence of initial parameters of water droplets on the performance of counter-rotating axial-flow compressor

This paper employs a numerical simulation method to investigate the wet compression working characteristics of a counter-rotating axial-flow compressor (CRAC) in an air-inlet, water-containing environment under different water droplet parameters at a designed rotational speed. The influence of initial water droplet parameters on the overall performance of the CRAC and the variations in the flow field characteristics under different wet compression conditions was investigated. The initial diameter of water droplets exhibited the most significant impact on the wet compression effect. Under an appropriate inlet water content, water droplets with smaller diameters effectively reduced the temperature of the CRAC’s internal flow field, increasing the air density. Consequently, the axial velocity decreased, altering the velocity triangle and increasing the rotor working capacity, which enhanced the performance of the CRAC. Additionally, wet compression influenced the flow field of the rear rotor stronger than that of the front rotor. When the initial diameter of water droplets is too large, the evaporative cooling effect cannot be fully exploited so wet compression only slightly improved the compressor performance. These findings may help understand the working characteristics of the CRAC in water-containing environments better, offering guidance for CRAC design using wet compression technology.

A dynamic modeling approach to predict water inflow during tunnel excavation in relatively uniform rock masses

Karst landforms are widely distributed all over the world. With the continuous improvement of infrastructure construction, tunnelling in mountainous karst areas is inevitable. Due to the complex hydrogeological conditions in karst areas, groundwater inflow during tunnelling is usually difficult to predict and can cause huge economic losses and casualties. Therefore, finding better ways to improve the prediction of tunnel water inflow is of great significance to ensure the safety of tunnelling. In this study, three commonly used modules (CHD, DRAIN and CFPM1) in MODFLOW are selected and compared to predict the water inflow of tunnels. We find that the CFPM1 module performs better in terms of considering both tunnel size and actual water inflow dynamics during tunnel excavation, which is a continuous process rather than an instantaneous process. Secondly, we build a hypothetical case and predict the tunnel water inflows using above three different modules. We find that the CHD module yields the largest initial and stable water inflow, followed by the DRAIN module, and the CFPM1 yields the least. Besides, as the most sensitive factor in the CFPM1 module, the influence of tunnel diameter on water inflow is discussed. Finally, taking the Shizishan Tunnel as an actual field example, we compare the simulation results of different modules with the measured tunnel inflow. In general, the prediction of the CFPM1 module is the closest to the measured value, and the prediction accuracy is the highest during the conventional tunnel construction process. However, when water-saturated karst features such as underground rivers, caves or faults are exposed during tunnelling, the water level may change instantaneously, which is more consistent with the principle of CHD module. In summary, this study provides theoretical and numerical support for the safe construction of relatively uniform rock mass tunnels in karst areas.

Hydration properties of magnesium phosphate cement paste mixed with metakaolin and silica fume

AbstractMagnesium phosphate cement (MPC) exhibits a faster setting time and higher early strength, making it suitable for crack repair. However, its application in civil engineering is hindered by its fast initial hydration rate and poor water resistance. To address these limitations, metakaolin (MK) and silica fume (SF) were utilized to enhance the properties of MPC. The effects of MK and SF on the setting time, compressive strength, water resistance, hydration process, and microstructure of MPC were investigated. The results demonstrate that both MK and SF significantly prolong the setting time of MPC and improve its water resistance. The main hydration products of MPC, after incorporating MK and SF, are k‐struvite (MgKPO4·6H2O) and unreacted MgO. The presence of MgSiO3 and AlPO4 also contributes to the enhancement of compressive strength and water resistance. The incorporation of MK and SF actively participates in the hydration reaction of the MPC system. Furthermore, MgSiO3 and AlPO4 intertwine with MKP, resulting in a denser internal structure of the cured MPC, thereby improving its water resistance.

Combination of Osmotic Dehydration and Further Drying to Improve the Quality of Dried Carrots

The food industry needs carrots as a processed product for dry products using drying technology to maintain product quality. The aim of the research was to examine the effect of osmotic dehydration temperature with ternary solution on the quality of carrots. The treatments studied were osmotic media temperatures of 25°C and 50°C combined with oven drying and infrared until the water content reached ±10%. Parameters measured after osmotic dehydration were loss of water and increase in solids, quality parameters after further drying were water content and post-storage quality parameters were carotenoids and rehydration test. The dehydration treatment resulted in a reduction of water of 27.25%-44.24% and addition of solids of 15.37%- 18.31%. The initial water content of carrots before osmotic treatment was 90%, the water content after osmotic at 25°C was 65.72% and 50°C was 63.29%. Combination of osmotic with oven requires 22-24 hours of drying time while infrared requires 8- 10 hours of drying time. The best carotenoid value was osmotic dehydration at 25°C followed by an oven or infrared with a value of 32.95(mg/100g)–31.94(mg/100g). Whereas at 50°C the rehydration values were in the range 271.14%-301.42% Keywords: Carrots, Infrared drying, Osmotic dehydration, Osmotic solution, Oven drying

Supersaturation dependent nucleation of methane + propane mixed-gas hydrate.

Before hydrates can be widely used in industry, we should better understand the problematic issues of hydrate nucleation, particularly its stochastic nature. Here, we report on measurements of the nucleation probability of mixed-gas hydrates in which the guest molecules are a mixture of methane and propane. For the pure cases, at a supersaturation near 1.0, we had previously measured an induction time for the methane hydrate of about 1h, whereas for the propane hydrate, it was over one day. Using the same experimental setup, we examine here the nucleation probability for a mixture of 90% methane and 10% propane as the guest gas for a range of supersaturations. For the experiments, the temperature was 274 ± 0.5K and the stirring rate was about 300rpm. The experiments were repeated at least ten times under the same condition, exchanging the sample water every time. We define the nucleation probability at a given time as the fraction of trials that nucleated by that time and then determine the nucleation probability distribution. The resulting nucleation frequency is found to have a power-law relation to supersaturation. Then, we examine how the nucleation frequency is affected by the existence of ultrafine bubbles in the initial water. We find that the ultrafine bubbles increase the nucleation frequency but much less than that of typical changes in supersaturation.

A New Water Film Depth Prediction Model for Pavement Surface Drainage

The prediction of the water film depth (WFD) on the road surface can help with road skid resistance research and reduce the risk associated with driving on rainy days. At present, there are many empirical and analytical models based on drainage length, slope, rainfall intensity and other parameters. Considering the influence of road surface runoff and starting from the Reynolds number formula of road surface water flow, a new road surface WFD calculation formula that considers the movement state of laminar water flow is derived. The results show that the changing trends of various parameters in the prediction model (drainage length, rainfall intensity, road slope) affecting WFD are consistent with those of the existing model. It is also found that the initial water film depth, initial speed of rainwater, and rainfall angle have little impact on WFD. The predicted value of the model has a suitable matching degree compared with the classical empirical model, which provides a new approach to the prediction of road water film depth.

Understanding Water Diffusion Behaviors in Epoxy Resin through Molecular Simulations and Experiments.

The unclear understanding of the water diffusion behavior posts a big challenge to the manipulation of water absorption properties in epoxy resins. Herein, we investigated the water diffusion behavior and its relationship with molecule structures inside an epoxy resin mainly by the nonequilibrium molecular dynamics and experiments. It is found that at the initial rapid water absorption stage, bound water and free water both contribute, while at the later slow water absorption stage, free water plays a dominant role. The observed evolution of free water and bound water cannot be explained by the traditional Langmuir model. In addition, molecule polarity, free volume, and segment mobility can all influence the water diffusion process. Hence, the epoxy resin with low polarity and high molecular segment mobility is endowed with higher diffusion coefficients. The saturated water absorption content is almost dependent on the polarity. The understanding of how water diffuses and what decides the diffusion process is critical to the rational design of molecule structures for improving the water resistance in epoxy resin.

The Economic Evaluation of Various Production Scenarios for Zubair Reservoir in the Kifl Field

This work evaluates the economic feasibility of various production scenarios for the Zubair reservoir in the Kifl oil field using cash flow and net present value (NPV) calculations. The Kifl field is an exploratory field that has not yet been developed or assessed economically. The first well was drilled in 1960, and three other wells were later drilled to assess the oil accumulation, so in this research, Different production scenarios were evaluated economically. These scenarios were proposed based on the reservoir model of the Zubair formation in the field. The research methodology used QUE$TOR software to estimate capital expenditures (CapEx) and operating expenditures (OpEx) based on field-level data, production profiles for each scenario, and produced fluid properties. CapEx estimates were mainly based on the number of drilled wells and plateau duration, while OpEx estimates were based on the number of barrels produced from each scenario. Cash flow values were estimated each year in the production interval after subtracting water handling costs, CapEx, and OpEx from the gross revenue of oil produced. The NPV for each scenario was then calculated using a 5% interest rate, and the most economical option was determined by comparing the NPV values of each scenario. Case-3 scenario was identified as the most economical option, with a high NPV value of approximately 612 MM$, an oil production rate of 10 MSTB/d, a Plateau duration of 3 years, a total number of wells of 11, and an Initial water cut of 13 %.