Water Leakage Research Articles

A novel approach for quantifying upper reservoir leakage

During the operational phases of the upper reservoir in a pumped storage power station, the water level, leakage area, and hydraulic gradient of the upper reservoir alter dynamically due to the cyclic pumping and draining activities. The rising groundwater level during storage introduces distinct leakage conditions within the reservoir basin, characterized by unsaturated, partially saturated, and saturated states. Consequently, reservoir basin leakage exhibits variability across these states. To address this issue, this study formulated rational assumptions corresponding to the three leakage states in a reservoir basin and derived analytical expressions for seepage calculation based on Darcy's law and the principles governing groundwater flow refraction. A case study was conducted to investigate the relationship between various factors and leakage. The results showed that leakage primarily depended on the permeability of the impermeable layer in the reservoir basin. The upper reservoir leakage was estimated, and the calculated leakage generally agreed with the measurements, offering insights into the leakage mechanism of the Liyang pumped storage power station. In addition, the reasons for disparities between measured and calculated leakage were analyzed, and the reliability of the developed method was validated. The findings of this study provide a foundation for the seepage control design of upstream reservoirs in similar projects.

Combining Cylindrical Voxel and Mask R-CNN for Automatic Detection of Water Leakages in Shield Tunnel Point Clouds

Water leakages can affect the safety and durability of shield tunnels, so rapid and accurate identification and diagnosis are urgently needed. However, current leakage detection methods are mostly based on mobile LiDAR data, making it challenging to detect leakage damage in both mobile and terrestrial LiDAR data simultaneously, and the detection results are not intuitive. Therefore, an integrated cylindrical voxel and Mask R-CNN method for water leakage inspection is presented in this paper. This method includes the following three steps: (1) a 3D cylindrical-voxel data organization structure is constructed to transform the tunnel point cloud from disordered to ordered and achieve the projection of a 3D point cloud to a 2D image; (2) automated leakage segmentation and localization is carried out via Mask R-CNN; (3) the segmentation results of water leakage are mapped back to the 3D point cloud based on a cylindrical-voxel structure of shield tunnel point cloud, achieving the expression of water leakage disease in 3D space. The proposed approach can efficiently detect water leakage and leakage not only in mobile laser point cloud data but also in ground laser point cloud data, especially in processing its curved parts. Additionally, it achieves the visualization of water leakage in shield tunnels in 3D space, making the water leakage results more intuitive. Experimental validation is conducted based on the MLS and TLS point cloud data collected in Nanjing and Suzhou, respectively. Compared with the current commonly used detection method, which combines cylindrical projection and Mask R-CNN, the proposed method can achieve water leakage detection and 3D visualization in different tunnel scenarios, and the accuracy of water leakage detection of the method in this paper has improved by nearly 10%.

Nurses Launch Billboard Campaign Against Renewal of Desert Regional Medical Center Lease

No abstract available. Article truncated after 150 words. The California Nurses Association and National Nurses United have launched a billboard campaign against the lease renewal of public-owned, Palm-Springs-based Desert Regional Medical Center to Dallas-based Tenet Healthcare (Figure 1) (1). The billboard campaign is in response to the posting of two videos that showed a water leak in Desert Regional's neurological intensive care unit and an infestation of cockroaches in the emergency department break room (2,3). Desert Regional is a public hospital governed by an elected district board. Tenet Healthcare is a private company that leases and runs the hospital. The nurses’ union said Tenet has a long-standing practice of short-staffing Desert Regional, which they said has caused patient safety issues (1). Tenet is currently in the process of renegotiating another 30-year lease with the hospital, which would include the option to purchase the hospital from the Desert Healthcare District at the end of the new lease (1). Desert …

Water-Related Properties and Biological Durability of Wood-Based Composites

There is insufficient data regarding the biodegradation of wood-based composites (WBC) by wood decay fungi. This study aimed to evaluate the biological durability and water-related properties of different WBC types. Although WBC are primarily designed for dry environments, in building applications, they may face increased moisture risks due to water leakage, condensation, or humid air. The panels, including oak-pine shield parquet (OPP), oriented strand board (OSB), birch plywood (BP), particle board (PB), laminated particle board (LPB), moisture-resistant particle board (MRPB), medium density fibreboard (MDF), laminated medium density fibreboard (LMDF) and moisture resistant medium density fibreboard (MRMDF), were subjected to attack by brown rot fungus Coniphora puteana. After 16 weeks of exposure, the most resistant WBC against biodegradation were BP, moisture-resistant MDF, and laminated MDF, as they exhibited a mass loss lower than 5 %. Conversely, all other WBC types showed high susceptibility to biodegradation, with a mass loss exceeding 35 %. LMDF (8 – 51 %) and MRMDF had the lowest water absorption (WA) within 168 h (2 – 46 %), while non-treated MDF exhibited the highest WA among all composite types with 190 % water uptake. With regards to thickness swelling, all WBC types, except for LPB and MDF, demonstrated values below 20 %. The influence of adhesives (phenol-formaldehyde or melamine urea-formaldehyde) used in WBC did not show a clear impact on water-related properties orbiological durability.

Rock mass quality prediction on tunnel faces with incomplete multi-source dataset via tree-augmented naive Bayesian network

Rock mass quality serves as a vital index for predicting the stability and safety status of rock tunnel faces. In tunneling practice, the rock mass quality is often assessed via a combination of qualitative and quantitative parameters. However, due to the harsh on-site construction conditions, it is rather difficult to obtain some of the evaluation parameters which are essential for the rock mass quality prediction. In this study, a novel improved Swin Transformer is proposed to detect, segment, and quantify rock mass characteristic parameters such as water leakage, fractures, weak interlayers. The site experiment results demonstrate that the improved Swin Transformer achieves optimal segmentation results and achieving accuracies of 92%, 81%, and 86% for water leakage, fractures, and weak interlayers, respectively. A multi-source rock tunnel face characteristic (RTFC) dataset includes 11 parameters for predicting rock mass quality is established. Considering the limitations in predictive performance of incomplete evaluation parameters exist in this dataset, a novel tree-augmented naive Bayesian network (BN) is proposed to address the challenge of the incomplete dataset and achieved a prediction accuracy of 88%. In comparison with other commonly used Machine Learning models the proposed BN-based approach proved an improved performance on predicting the rock mass quality with the incomplete dataset. By utilizing the established BN, a further sensitivity analysis is conducted to quantitatively evaluate the importance of the various parameters, results indicate that the rock strength and fractures parameter exert the most significant influence on rock mass quality.

The implication of water accessibility challenges to urban water governance in Morogoro municipality, Tanzania

This study investigates water accessibility challenges in urban and peri-urban areas and its implication to urban water governance in Morogoro Municipality, Tanzania. A cross-sectional research design was adopted using a survey of 90 randomly selected households. The key informant interview was used to collect key information. Quantitative data were analyzed using descriptive statistics. The Mann-Whitney U Test was employed to establish the extent to which factors affected water accessibility differently in urban and peri-urban areas. Content analysis was used to analyse qualitative information. Approximately 69% of the respondents accessed water from public piped water system. Some accessed water from public water taps while others used private boreholes and tank carts. Water supply, more so in peri-urban areas, was not reliable. In addition, water leakage, cost of connecting to the public piped water system, cost for constructing a borehole, climatic and environmental factors piled up into challenges of water accessibility suggesting poor urban water governance. The Mann-Whitney U Test showed that households in peri-urban areas were significantly affected by the challenges compared to households in urban areas at 5% level of significance where p = 0.000. The study concludes presence of challenges in water access due to multiple factors with implications on urban water governance. Therefore, urban water governance should be improved to heighten water accessibility. Further studies should focus on developing an urban water governance framework in Tanzania.

Ecological-Based Mining: A Coal–Water–Thermal Collaborative Paradigm in Ecologically Fragile Areas in Western China

A substantial reduction in groundwater level, exacerbated by coal mining activities, is intensifying water scarcity in western China’s ecologically fragile coal mining areas. China’s national strategic goal of achieving a carbon peak and carbon neutrality has made eco-friendly mining that prioritizes the protection and efficient use of water resources essential. Based on the resource characteristics of mine water and heat hazards, an intensive coal–water–thermal collaborative co-mining paradigm for the duration of the mining process is proposed. An integrated system for the production, supply, and storage of mining companion resources is achieved through technologies such as roof water inrush prevention and control, hydrothermal quality improvement, and deep-injection geological storage. An active preventive and control system achieved by adjusting the mining technology and a passive system centered on multi-objective drainage and grouting treatment are suggested, in accordance with the original geological characteristics and dynamic process of water inrush. By implementing advanced multi-objective drainage, specifically designed to address the “skylight-type” water inrush mode in the Yulin mining area of Shaanxi Province, a substantial reduction of 50% in water drillings and inflow was achieved, leading to stabilized water conditions that effectively ensure subsequent safe coal mining. An integrated-energy complementary model that incorporates the clean production concept of heat utilization is also proposed. The findings indicate a potential saving of 8419 t of standard coal by using water and air heat as an alternative heating source for the Xiaojihan coalmine, resulting in an impressive energy conservation of 50.2% and a notable 24.2% reduction in carbon emissions. The ultra-deep sustained water injection of 100 m3·h−1 in a single well would not rupture the formation or cause water leakage, and 7.87 × 105 t of mine water could be effectively stored in the Liujiagou Formation, presenting a viable method for mine–water management in the Ordos Basin and providing insights for green and low-carbon mining.

Corrosion Risk for Process Safety in the Chemical Industry

The aim of this work is to analyze how corrosion risk management influences process safety. Both issues occupy an important niche in the chemical industry. Corrosion risk management includes identifying, analyzing, assessing, and managing corrosion hazards. Process safety is a discipline that focuses on preventing fires, explosions, and accidental releases at chemical process facilities. Corrosion can cause all these detrimental events. 
 There is much literature about both topics, corrosion risk, and process safety, separately, but there are nearly no research works concerning intersection and influence.
 The level of corrosion failure and its consequences, defining corrosion risk, may be different: the leak of crude oil, natural gas, water, liquid and gaseous hazardous chemicals, fire, explosion, damages, deterioration of the environment, injuries, and death of people and animals. Due to the biological and psychological properties of human nature, we are unlikely to exclude human mistakes.
 We should pay significant attention to education, dissemination of information, knowledge transfer, collaboration, and communication. Correct corrosion risk management gives rise to the improvement of process safety at stages of design, fabrication, implementation, erection, service, and maintenance of equipment and constructions in the chemical industry.
 For this realization, specific corrosion mitigation strategies and technologies are described. They are successfully implemented in the chemical industry. It shows how corrosion management and process safety management can be better integrated into practice.
 The future consideration of the prognosis of corrosion risk with process safety is connected with corrosion modeling. Limitations and challenges of such a forecast are discussed too.
 Special educational and training programs are developed to help engineers, scientists, professionals, students, and managers learn about corrosion science and engineering

Research on fracture propagation of hydraulic fracturing in a fractured shale reservoir using a novel CDEM-based coupled HM model

Shale reservoirs are usually buried deep, and contain lots of complex natural fractures (NFs) under the influence of tectonic stress and faults. Previous studies usually focus on small-scale reservoir models and there is also a lack of research that completely focuses on NF characteristics. Using the continuous-discontinuous element method (CDEM), a Hydro-Mechanical (HM) coupling model was constructed to explore the propagation mechanism of hydraulic fracture (HF) and the effects of NF characteristics on HF propagation. The results show that as the HF approaches the NFs, the NFs preferentially tend to undergo shear failure, resulting in a decelerated HF propagation rate and an increased injection pressure. After water enters the NFs, the HF rapidly propagates, so the fracture area swiftly increases and the HF has a more tortuous fracture morphology. The NF orientation (α) and the internal friction angle (φ) exhibit a pronounced and distinct effect on HF propagation. Specifically, when α is 30°∼60°, the HF propagation is more tortuous and complex, so it is easier to form a larger transverse reconstruction range. When the NF density (η) is no less than 0.12, the HF tends to open the NFs and form a more tortuous morphology, but a higher η does not necessarily imply a higher fracture complexity. A longer NF (l > 12 m) benefits to improve the longitudinal reservoir reconstruction scope, but has little impact on the overall reconstruction effect. In the presence of stress shadow effect, it is improbable for the HF to completely open the intersecting NFs; instead, it typically opens only a segment or one of them. Consequently, it may be challenging to establish a fracture network with the simultaneous development of primary and branching fractures. Additionally, some water leakage into the inactive NFs gives rise to a decline in both the fracture length and fracture area. The findings can offer theoretical insights for refining the fracturing design in shale reservoirs with NFs.

Nitrogen Loss and Migration in Rice Fields under Different Water and Fertilizer Modes.

Irrigating aquaculture wastewater in appropriate irrigation and drainage modes in paddy fields could reduce water and fertilizer loss. However, the precise mechanisms involved in the degradation and movement of nitrogen in various water and fertilizer modes are still not fully understood. This study involves conducting a controlled experiment using barrels to examine the effects of various water quality, irrigation and drainage methods, and fertilization levels. The aim is to analyze the patterns of nitrogen degradation, loss, migration, and absorption in surface water, underground drainage, and soil leakage at different depths. The results showed the following: (1) The paddy field has a significant purification effect on aquaculture wastewater after one day of irrigation, reached at 78.55-96.06%. (2) Aquaculture wastewater irrigation increased nitrogen concentration in the plough layer, which helps rice roots absorb nitrogen and boosts plant TN. (3) In special dry years, underground seepage is the predominant method of nitrogen loss, and underground drainage nitrogen concentration peaks 2-6 days after fertilization. (4) Under aquaculture wastewater irrigation, the TN loss load of II decreased by 27.65-42.45% than FSI. Compared with IA-80, the TN degradation rate of IA in surface water increased by 18.51%, TN loss load decreased by 5.48%, TN absorption rate significantly increased by 14.61%, and yield increased by 31.14% significantly. IA is recommended in special dry years, which can improve the TN absorption rate and ensure high yield while significantly reducing the loss load of nitrogen. The findings can provide a basis for the purification of aquaculture wastewater through paddy field ecosystems in response to fertilizer supply levels.

Numerical investigation of the instability of dry granular bed induced by water leakage

AbstractUnderground pipe defects or cracks under transport infrastructure can cause water leakage to upper soil layers (e.g. subgrade and capping), inducing local cavities or even failure of overlying road/railway formation. Although numerous studies on the instability of granular beds induced by injected water have been conducted, most of them focused on the behaviour of saturated granular beds, while research on dry granular beds is still limited. This paper aims to address this gap using a numerical model coupling volume of fluid method with discrete element method. We observed that dry granular beds go through three distinct regimes as water jet velocity increases including stationary, stable deformation with heave and fluidisation. However, the flow velocities required to deform and fluidise dry granular beds are significantly higher than those required for saturated beds. Increasing granular bed thickness can alter its failure mechanism from full depth to localised erosion, leading to cavity formation around pipe cracks prior to the bed fluidisation. The gravitational and frictional components of granular mass are identified as two main resisting forces of dry granular beds against water jet force, evidenced by the increase of critical jet velocities as particle density and friction coefficient increase. Nevertheless, the moblised zone of granular mass is practically independent of both the buried depth of dry granular beds.

A Review Article on Analysis and Design of Water Distribution Network for Jabalpur antonment Board Area

The provision of a reliable and efficient water distribution system is fundamental for ensuring adequate water supply to urban areas. This review article aims to analyze and evaluate the design aspects, hydraulic performance, and challenges related to the water distribution network in the Jabalpur Cantonment Board Area. The study comprehensively examines the current state of the water distribution system, evaluates its operational efficiency, and proposes recommendations for enhancing its performance and sustainability.The review commences by providing an overview of the Jabalpur Cantonment Board Area, highlighting the demographic, geographic, and infrastructural aspects relevant to the water distribution network. It delves into the existing system layout, network configuration, pumping stations, reservoirs, pipe materials, and other infrastructure components contributing to the distribution of potable water to the residents.Furthermore, the review article conducts a detailed analysis of hydraulic modeling techniques and software applications utilized in assessing the performance and optimization of the water distribution network. It scrutinizes factors influencing network efficiency, including water demand patterns, pressure management, leakage detection, and water loss reduction strategies.Through a critical evaluation of the existing challenges faced by the water distribution network in Jabalpur Cantonment, the review identifies issues such as aging infrastructure, inadequate maintenance, uneven distribution, non-revenue water, and insufficient pressure management.

District metered areas determination for water distribution networks using improved Girvan-Newman algorithm

In general, partitioning networks into district metered areas (DMA) is known as a practical method to manage the pressure and reduce water leakage in Water Distribution Networks (WDNs). Different methods such as engineering judgment, optimization techniques, and graph theory are proposed to determine the DMA. The graph theory is a traditional method for partitioning networks including several algorithms. One of these algorithms is the Girvan-Newman (GN) algorithm which is based on the mathematical parameters without considering the characteristics of networks. In other words, the hydraulic quality and quantity condition of WDNs are not used for DMA determination. Therefore, in this research, a new method is proposed to improve the performance of the GN algorithm for DMA determination considering the quantities of water networks. For this purpose, the average values of nodal pressure and residual chlorine concentration are calculated and used simultaneously for the junction’s weight determination. Then, the edge scores are calculated based on the junction’s weights, and the edges with the maximum scores are removed until to reach the desired number of DMAs. For comparison purposes, here, the Demand-Driven Simulation Method (DDSM) and Head-Driven Simulation Method (HDSM) analyses are used for the analysis of the Poulakis WDN, selected as a case study. A comparison of the results shows that by using the proposed method, the average pressure values are decreased and the average residual chlorine concentration values are increased. In other words, the pressure values are decreased from 16.32% to 26.23% and the average residual chlorine concentration values are increased from 2.5% to 18.37% in comparison with the results of the standard form of the GN algorithm using both DDSM and HDSM analyses. Furthermore, by using the proposed method, in all scenarios, the hybrid reliability values increase in comparison with the GN algorithm. The results indicate the unique performance of the proposed method in comparison with the standard form of the GN algorithm for DMA determination of WDNs.

Real-time and non-destructive control of the freshness and viability of live mussels through portable near-infrared spectroscopy

This study introduces the application of a novel, rapid, and non-destructive method employing portable near-infrared (NIR) spectroscopy to assess the freshness and viability of live mussels throughout their shelf-life. NIR spectra ranging from 908 to 1676 nm were collected from 150 Mediterranean mussels (Mytilus galloprovincialis, L.) over a 10-day storage period. Simultaneously, measurements of weight loss, intravalvular liquid pH, and nonprotein nitrogen levels were taken. A predictive model was established by correlating the multivariate information derived from NIR spectral data with days of storage under refrigerated conditions using orthogonal partial least squares regression (OPLSR) analysis. While physical and chemical parameters (except for gradual weight loss due to water leakage) showed no distinct trends throughout storage, the fourth derivative-preprocessed NIR spectra enabled the construction of an OPLSR model that, following cross-validation, exhibited a correlation coefficient of 0.86 and, following external validation with new mussel samples, an average accuracy (root mean square error of prediction) of just 1.3 days. The predictive power of the model was primarily attributed to specific NIR wavelengths associated with key chemical features, including unsaturated fatty acids, nitrogen compounds, water content, glycerol, and ATP-related compounds that, collectively, constituted a distinctive fingerprint for forecasting mussel storage duration. The performance of the tool, along with its environmentally friendly, non-invasive, real-time, and cost-effective characteristics, align with industry control procedures and inspection needs, allowing effective freshness and viability assessment of live mussels across the food supply chain.

An IoT-Based Water Leakage Detection and Localization System

In this research, we present a proposed Internet of Things based model, which we have named iWaLDeL, for the detection and localization of water leakages which we simulated for the Ghana Water Company (GWC) pipe network, using YF-S201 Flow Rate Sensors and Static Leak Detection techniques. Through an extensive review of existing methods, the research highlights the limitations of traditional detection approaches and emphasizes the potential of modern technologies. The iWaLDeL system harnesses the power of IoT devices, deploying an array of strategically placed sensors capable of detecting leakages and pressure variations. These sensors form a distributed network which communicates with a central hub, ensuring comprehensive coverage of the monitored area. Crucially, the research delves into the innovative aspect of leak localization. By combining data from multiple sensors and pipes, the system can estimate the precise location of a leakage following a mathematical model we developed. This localization capability significantly reduces the time required for maintenance teams to address leakage issues, minimizing water loss and further damages. To validate its effectiveness, the system was prototyped and tested, which demonstrated a successful leak detection and localization, showcasing its adaptability in both residential and commercial settings. The system’s seamless integration with existing smart infrastructure enhances its feasibility for real-world implementation.

Fabrication of poly(vinyl alcohol) foam/gel composite used for cold storage by combing molding foaming and freeze-thawing technologies

Ice, the widely used low-temperature storage material, plays an important role in the short-time cold chain transportation. To avoid water leakage caused by ice melting, special encapsulation is needed, but inevitably leads to the single shape and the poor contact between ice and the cooled object. It is urgent to develop a new type of leakage-proof cold storage material. Accordingly, in this paper, by combing the technologies of molding foaming and freeze-thawing, a novel cold storage material containing poly(vinyl alcohol) (PVA) carrier foam and PVA gel was fabricated. PVA carrier foam mainly provided the strength foundation, while PVA gel locked the absorbed water. With the addition of 7.0 wt% PVA gel into PVA carrier foam, denser and uniform cells were formed, endowing the foam/gel composite with good shape retention. Even after 500 times’ cyclic compression, the compression curve of the composite still coincided with the original one. The further introduction of 2.0 wt% NaCl into PVA gel enhanced the cold storage effect of the composite, i.e., the temperature in an incubation box could reach −2.5 °C and be maintained for 16 h. This novel PVA foam/gel composite was expected to be used as cold storage material for cold chain transport, and thus broadening the practical application of PVA.

Evaluating optimized irrigation strategies on crop productivity and field water utilization under micro sprinkling irrigation in typical cropping systems of the Huang-Huai-Hai Plain

Inefficient traditional irrigation methods have negative consequences for agricultural production and the depletion of groundwater resources. This two-year field experiment aimed to evaluate optimized irrigation practices for irrigation efficiency (IE) and water utilization in winter wheat-maize (W-M) and winter wheat-soybean (W-S) annual rotation systems. Four micro-sprinkler-based irrigation strategies were implemented during the winter wheat season, specifically when the soil water content (SWC) of the 40 cm soil layer reached 40% of the field capacity (FC) after sowing. Including W4 (irrigated to SWC at 40 cm reached 60% FC), W6 (irrigated to SWC at 60 cm reached 80% FC), FI (farmer's practice, with irrigation amount of 150 mm per irrigation, the same timing as W6), and a rain-fed (RF) as a control. Summer seasons had no irrigation except for emergence. The WHCNS model simulated water consumption. The results indicated that IE decreased with increasing irrigation volumes, and the W-S system demonstrated higher IE than W-M. Both W4 and W6 achieved the desired wetting zones, while FI resulted in water leakage. Surface runoff was not affected by irrigation. Compared to the FI treatment under both cropping systems, W4 significantly reduced field water losses, particularly deep percolation, by 18.3–39.4%. W6 and FI led to elevated winter wheat transpiration rates, impacting crop yield. W4 had comparable yields to W6 and FI, but higher crop water productivity with average increases of 17.9% and 21.3% in W-M, and 24.6% and 31.4% in W-S, respectively. W4 also showed higher harvest indexes in both systems. The W-S system had more stable interannual yields, higher water-holding capacity, and water use efficiency than W-M. Although RF had great water-saving potential, its yield losses were enormous. These optimized precision irrigation strategies significantly reduce water consumption while achieving substantial yield increases, thereby providing vital support for sustainable agricultural development.

Assessment of Blue Water Migration and Efficiency in Water-Saving Irrigation Paddy Rice Fields Using the Water Flow Tracking Method

Although irrigation systems largely sustain global agricultural production, their efficiency is often alarmingly low. While irrigation water (blue water) is critical for the water-saving irrigation of rice with a high water demand, the process and efficiency of irrigation water utilization need clarification. In this study, we examined the three commonly used irrigation and drainage patterns (frequent shallow irrigation (FSI), wet and shallow irrigation (WSI), and rain-catching and controlled irrigation (RCI)) in rice fields. We developed a tracking method for irrigation water flow decomposition, which includes irrigation water evapotranspiration (IET), irrigation water drainage (IDR), irrigation water leakage (IPC), and irrigation water field residual (IRE). Using this method, we established an irrigation water efficiency evaluation index system and a comprehensive evaluation method. Our tracking method is relevant to describing the irrigation water performance under varying irrigation and drainage patterns. The results revealed that the average irrigation water input for the three irrigation and drainage patterns between 2015 and 2018 was roughly 312.5 mm, wherein IET accounted for 148 mm. However, more than 50% of the irrigation water outflow, comprising IDR, IPC, and IRE, exceeded the total amount of irrigation water input. The mean values of the gross irrigation efficiency (GIE), net irrigation efficiency (NIE), and effective consumption ratio (ECR) for all treatments in the three-year period were 0.63, 0.47, and 0.75, respectively. Additionally, the irrigation water use efficiency was significantly higher in dry years compared to wet years. The fuzzy composite rating values of the three irrigation and drainage models from 2015 to 2018 were RCI, WSI, and FSI, in descending order, under varying precipitation conditions. The RCI patterns maintained a high composite rating value (greater than 3.0) under different precipitation conditions. Previous efficiency calculations disregarded the blue–green water migration process and did not differentiate the blue–green water flow direction in agricultural fields, creating significant biases in the outcomes. This study’s method offers a new approach to evaluate the use of blue water resources in farmland.

Hydraulic Performance Optimization of a Submersible Drainage Pump

Small submersible drainage pumps are used to discharge leaking water and rainwater in buildings. In an emergency (e.g., heavy rain or accident), advance monitoring of the flow rate is essential to enable optimal operation, considering the point where the pump operates abnormally when the water level is increased rapidly. Moreover, pump performance optimization is crucial for energy-saving policy. Therefore, it is necessary to meet the challenges of submersible pump systems, including sustainability and pump efficiency. The final goal of this study was to develop an energy-saving and highly efficient submersible drainage pump capable of performing efficiently in emergencies. In particular, this paper targeted the hydraulic performance improvement of a submersible drainage pump model. Prior to the development of driving-mode-related technology capable of emergency response, a way to improve the performance characteristics of the existing submersible drainage pump was found. Disassembling of the current pump followed by reverse engineering was performed instead of designing a new pump. Numerical simulation was performed to analyze the flow characteristics and pump efficiency. An experiment was carried out to obtain the performance, and it was validated with numerical results. The results reveal that changing the cross-sectional shape of the impeller reduced the flow separation and enhanced velocity and pressure distributions. Also, it reduced the power and increased efficiency. The results also show that the pump’s efficiency was increased to 5.56% at a discharge rate of 0.17 m3/min, and overall average efficiency was increased to 6.53%. It was concluded that the submersible pump design method is suitable for the numerical designing of an optimized pump’s impeller and casing. This paper provides insight on the design optimization of pumps.

Pollution simulation of heavy metal in saturated porous media using CFD

Visualizing contaminant transport can play a significant role in better understanding the fate of contaminants in soil. The present study aimed to evaluate contamination of aluminium and mercury in the soil through the use of computational fluid dynamics (CFD) to obtain an estimate of degraded zones. A leak from a generic stabilization pond measuring 40 m (length) and 20 m (width) was developed for the simulations. The simulations were carried out for a period of 10 years with different leak speeds, water inlet flow rates and different values of aluminum and mercury volume fractions. All governing equations was solved with the transient mode. The flow characterized as laminar, and the multiphase model was employed through the Mixture method. The time required for contamination to reach its maximum value was directly influenced by the change in speed values. The concentration of the pollutant increases as the water inlet and leakage speeds increase, however, it reduces the time needed to reach the highest pollutant value, indicating that the degree of pollution of the porous medium was greater. The study shows that contamination can be seen as a potential contaminant source for groundwater.