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IntroductionSalinity stress causes reduction of crop evapotranspiration (ETc) and yield. An unsuitable seed planting date can result in negative atmospheric effects, such as temperature stress, during the crop growth period. Consequently, salinity stress and unfavorable climatic conditions during this period interact to reduce crop water uptake. The mentioned conditions effect, should be investigated on crop transpiration amount (actual water requirement) and soil surface evaporation losses. This research results will have a determinative effect on the optimal use of water resources. Materials and MethodsThe studied crop in this research was S.C 704 maize. The crop planting was conducted in mini-lysimeters with a diameter of 40 cm and a height of 70 cm. The experiment factors included soil salinity stress and seed planting date. Soil salinity treatments were selected at four levels of 1.7 (S1), 2.5 (S2), 3.8 (S3), 5.9 (S4) dS.m-1. Seed planting date included of 5 May (P1), 25 May (P2) 14 June (P3) and 4 July (P4). Crop growth period for all planting date treatments, was 140 days (FAO-56). Experiment was conducted as factorial based on completely randomized design with 16 treatments and three repetitions. Variance analysis and average comparison of data was done by SPSS software and with Duncan's multi-range test (at 5% probability level). Daily soil moisture amount was measured by a moisture meter. Irrigation time was determined for without water stress conditions. Readily available water limit was determined 0.4. Irrigation volume was calculated according to soil moisture deficit (up to FC limit), soil density, root depth, leaching fraction and soil surface area. To separate the evapotranspiration components, all treatments were performed in two series of mini-lysimeters. In the first series, soil moisture reduction was related to crop evapotranspiration amount. But in the second series, the plastic mulch was placed on soil surface. Soil moisture reduction in the second series, was only related to crop transpiration amount. Difference of data in the first and second series was equal to the evaporation amount. Linear function of Mass and Hoffman (1977) was used as the function of evapotranspiration-salinity, transpiration-salinity, and evaporation-salinity. Results and DiscussionAs salinity increased from S1 to S4 levels, evapotranspiration, transpiration, and evaporation amounts were measured on the planting dates P1, P2, P3, and P4. The measurements were as follows:Evapotranspiration (mm): 619-548 (P1), 621-549 (P2), 624-547 (P3), and 625-544 (P4)Transpiration (mm): 429-309 (P1), 421-295 (P2), 418-281 (P3), and 412-265 (P4)Evaporation (mm): 190-239 (P1), 200-254 (P2), 206-266 (P3), and 213-279 (P4)These ranges reflect the measured amounts for each variable under increasing salinity levels across the different planting dates. Under the influence of salinity stress, soil water potential decreases, leading to a reduction in water uptake by the crop and subsequently decreased crop transpiration. As a result of this reduction in crop water uptake, the remaining water in the soil is utilized for evaporation. In S4 level and on dates of: P1, P2, P3 and P4, crop transpiration portion decreased to 12.9%, 14.1%, 15.6% and 17.2%, respectively, and evaporation portion increased to the same amount. By adjusting the seed planting date to optimize the utilization of favorable atmospheric conditions during crop growth stages, the increase in the portion of evaporation is prevented. In initial stage of growth period, only 0 to 10% of soil surface is covered by crops (FAO-56) causing the evaporation component to have a dominant portion in the crop evapotranspiration parameter. As a result, placing of initial growth stage in warm days of year caused an increase in evaporation losses. It seems that S1P1 treatment was the optimal condition for transpiration increase and evaporation decrease. The estimated functions showed that (in salinity stress conditions) crop transpiration decreased more than ETc. Therefore, the transpiration rate should be considered as the crop's net water requirement instead of ETc (crop evapotranspiration). According to the Mass-Hoffman function, under stress conditions, the decreasing slope of transpiration and evapotranspiration and the increasing slope of evaporation become more pronounced. For instance, in planting dates of P1, P2, P3, and P4, for each unit (dS.m-1) of increase in soil salinity, the evapotranspiration rates decreased by 2.51%, 2.82%, 3.3%, and 3.65%, respectively. Similarly, the transpiration rates decreased by 6.1%, 7.34%, 8.42%, and 9.2%, respectively, while the evaporation rates increased by 5.5%, 6.7%, 7%, and 7.82%. ConclusionSalinity and atmospheric temperature stresses had interaction effects on evapotranspiration and components rates. Postponing the seed planting date and not utilizing optimal weather conditions, especially during spring, can lead to damage to transpiration, which is a favorable aspect; however it is unfavorable in evaporation,. Therefore, in irrigated crops, it is advisable not to plant seeds during the warm months of the year, especially in July and August. Consequently, by controlling soil salinity and selecting the appropriate planting date, water can be optimally utilized.

While only a minimal fraction of global water resources is accessible for drinking water production, their uneven distribution combined with the climate crisis impacts leads to challenges in water availability. Leakage in water distribution networks compounds these issues, resulting in significant economic losses and environmental risks. A coherent review of (a) the most widely applied water loss estimation techniques, (b) factors influencing them, and (c) strategies for their resilient reduction provides a comprehensive understanding of the current state of knowledge and practices in leakage management. This work aims towards covering the most important leakage estimation methodologies, while also unveiling the factors that critically affect them, both internally and externally. Finally, a thorough discussion is provided regarding the current state-of-the-art technics for leakage reduction at the municipal-wide level. [ABSTRACT FROM AUTHOR]

Background and Objectives In order to use water efficiently in agriculture, it is necessary to know the amount of water leakage from canals. In this study, evaluation of earthen canals and canals of irrigation and drainage networks of Khuzestan province was performed by calculating water distribution efficiency. The traditional method of conveyancing agricultural water from the extraction point to the farm is using earthen canals, which, although low initial cost, due to the need for short-term dredging and weed clearing, has a high maintenance cost and most importantly water losses, which sometimes reaching up to 70% (Ghobadian and Khalaj 2012). The average water transfer efficiency in 40 canals in Moghan Agro-Industrial Zone, in the canals related to Agro-Industrial lands, channel A and return channel A, were equal to 87.7, 90.9 and 86.8%, respectively. The average waiting time of farmers was 30 minutes per kilometer and land losses were set at 35 square meters per hectare (Akhavan and Abbasi 2013). Therefore, the lack of sufficient studies led to the statistical analysis of distribution efficiency in canals and earthen canals in Khuzestan province to be evaluated in a research project. Methodology The present study was conducted based on the results of field visits and data collection from different locations of modern distribution networks including tertiary and fourth degree channels as well as the traditional water distribution irrigation network in the cities of Khuzestan province in 2017. In this method, two consecutive sections of semi-elliptical prefabricated canalets and earthen canal were selected. According to the current cross-sectional conditions, the flow velocity was measured. The flow velocity measurement was performed using propeller current meter device in each section and finally the flow rate of two input and output sections was calculated. In this study, 29 canals including 17 tertiary and fourth degree channels and 12 tertiary and fourth degree earthen channels were evaluated. 16 canals were covered by irrigation and drainage networks of Khuzestan and one canal in Baghmalek city was under the management of farmer. Six earthen canals under the management of farmers and six other tertiary and fourth degree earthen channels were covered by Statistical Analysis of Conveyance irrigation and drainage networks in Khuzestan province. Oneway analysis of variance was performed with SPSS16 software. To compare the numbers of distribution efficiency indices (percent), it is necessary to eliminate the scale difference. Therefore, the standard Z-Score standardization method was used to resolve the scale difference. Findings The lowest and highest distribution efficiencies were calculated at 46.88 and 99.69% in Baghmalek and Shushtar counties. The average distribution efficiency in all studied channels was 79.75%. The results of variance analysis of distribution efficiency means showed that there was a significant difference between the distribution efficiency means in semi-elliptical prefabricated canalets, personal canals, non-personal semi-elliptical prefabricated canalets and erathen canals at the level of 5%. The average distribution efficiencies in canals and earthen canals were 86.47 and 70.23%, respectively. The lowest average distribution efficiency in the dedicated channel (under farmer management) was 46.88% and the highest distribution efficiency in the non-dedicated channel was 99.67%. The Z-Score proportions calculated for the distribution efficiency based on the type of construction material showed that 72.1% of the semi-elliptical prefabricated canalets were in acceptable condition, while this rate was only 9.1% in the earth channels. All grade 4 channels had acceptable distribution efficiencies. 59.1% of non-specific channels (under the cover of irrigation and drainage networks of Khuzestan) had acceptable distribution efficiency while 85.7% of specific channels did not have acceptable distribution efficiency. Conclusion In this study, the values of distribution efficiency calculated in different canals showed that the type of ownership of canal is effective in increasing the distribution efficiency. In a way the average distribution efficiency in the canals covered by irrigation and drainage networks as non-personal channels were significantly different from the channels managed by the farmer (private channels) at the level of 5%. Scientific management performed by irrigation and drainage networks in Khuzestan province caused about 60% of non- private water distribution channels to have acceptable irrigation efficiency, while the lack of scientific management on personal canals (under farmer management) including non-volume delivery of water due to mismanagement measurement structures has caused about 85% of channels under farmer management do not have acceptable distribution efficiency. By delivering a volume of water through personal channels to the operator, it increases the distribution efficiency in the channels under farmer management. [ABSTRACT FROM AUTHOR]

IntroductionSalinity stress causes reduction of crop evapotranspiration (ETc) and yield. An unsuitable seed planting date can result in negative atmospheric effects, such as temfaature stress, during the crop growth faiod. Consequently, salinity stress and unfavorable climatic conditions during this faiod interact to reduce crop water uptake. The mentioned conditions effect, should be investigated on crop transpiration amount (actual water requirement) and soil surface evaporation losses. This research results will have a determinative effect on the optimal use of water resources. Materials and MethodsThe studied crop in this research was S.C 704 maize. The crop planting was conducted in mini-lysimeters with a diameter of 40 cm and a height of 70 cm. The exfaiment factors included soil salinity stress and seed planting date. Soil salinity treatments were selected at four levels of 1.7 (S1), 2.5 (S2), 3.8 (S3), 5.9 (S4) dS.m-1. Seed planting date included of 5 May (P1), 25 May (P2) 14 June (P3) and 4 July (P4). Crop growth faiod for all planting date treatments, was 140 days (FAO-56). Exfaiment was conducted as factorial based on completely randomized design with 16 treatments and three repetitions. Variance analysis and average comparison of data was done by SPSS software and with Duncan's multi-range test (at 5% probability level). Daily soil moisture amount was measured by a moisture meter. Irrigation time was determined for without water stress conditions. Readily available water limit was determined 0.4. Irrigation volume was calculated according to soil moisture deficit (up to FC limit), soil density, root depth, leaching fraction and soil surface area. To separate the evapotranspiration components, all treatments were faformed in two series of mini-lysimeters. In the first series, soil moisture reduction was related to crop evapotranspiration amount. But in the second series, the plastic mulch was placed on soil surface. Soil moisture reduction in the second series, was only related to crop transpiration amount. Difference of data in the first and second series was equal to the evaporation amount. Linear function of Mass and Hoffman (1977) was used as the function of evapotranspiration-salinity, transpiration-salinity, and evaporation-salinity. Results and DiscussionAs salinity increased from S1 to S4 levels, evapotranspiration, transpiration, and evaporation amounts were measured on the planting dates P1, P2, P3, and P4. The measurements were as follows:Evapotranspiration (mm): 619-548 (P1), 621-549 (P2), 624-547 (P3), and 625-544 (P4)Transpiration (mm): 429-309 (P1), 421-295 (P2), 418-281 (P3), and 412-265 (P4)Evaporation (mm): 190-239 (P1), 200-254 (P2), 206-266 (P3), and 213-279 (P4)These ranges reflect the measured amounts for each variable under increasing salinity levels across the different planting dates. Under the influence of salinity stress, soil water potential decreases, leading to a reduction in water uptake by the crop and subsequently decreased crop transpiration. As a result of this reduction in crop water uptake, the remaining water in the soil is utilized for evaporation. In S4 level and on dates of: P1, P2, P3 and P4, crop transpiration portion decreased to 12.9%, 14.1%, 15.6% and 17.2%, respectively, and evaporation portion increased to the same amount. By adjusting the seed planting date to optimize the utilization of favorable atmospheric conditions during crop growth stages, the increase in the portion of evaporation is prevented. In initial stage of growth faiod, only 0 to 10% of soil surface is covered by crops (FAO-56) causing the evaporation component to have a dominant portion in the crop evapotranspiration parameter. As a result, placing of initial growth stage in warm days of year caused an increase in evaporation losses. It seems that S1P1 treatment was the optimal condition for transpiration increase and evaporation decrease. The estimated functions showed that (in salinity stress conditions) crop transpiration decreased more than ETc. Therefore, the transpiration rate should be considered as the crop's net water requirement instead of ETc (crop evapotranspiration). According to the Mass-Hoffman function, under stress conditions, the decreasing slope of transpiration and evapotranspiration and the increasing slope of evaporation become more pronounced. For instance, in planting dates of P1, P2, P3, and P4, for each unit (dS.m-1) of increase in soil salinity, the evapotranspiration rates decreased by 2.51%, 2.82%, 3.3%, and 3.65%, respectively. Similarly, the transpiration rates decreased by 6.1%, 7.34%, 8.42%, and 9.2%, respectively, while the evaporation rates increased by 5.5%, 6.7%, 7%, and 7.82%. ConclusionSalinity and atmospheric temfaature stresses had interaction effects on evapotranspiration and components rates. Postponing the seed planting date and not utilizing optimal weather conditions, especially during spring, can lead to damage to transpiration, which is a favorable aspect; however it is unfavorable in evaporation,. Therefore, in irrigated crops, it is advisable not to plant seeds during the warm months of the year, especially in July and August. Consequently, by controlling soil salinity and selecting the appropriate planting date, water can be optimally utilized. [ABSTRACT FROM AUTHOR]

The efficient use of the irrigation systems constitutes an aspect of vital importance for the achievement of appropriate securities of water productivity. This efficiency will be conditioned in great measure by the behavior of the climatic variables during the irrigation process. With the objective of valuing the effect of the direction of the wind in the quality of the irrigation with central pivot machines in dependence of the different positions that it occupies during the irrigation an evaluation was carried out in the UBPC Victoria II of the Empresa Agropecuaria Camagüey. Were determined the parameters of the irrigation quality in three positions of the machine regarding wind direction, two in the direction of the wind and one perpendicular. The results indicate a variation in the behavior of the valued parameters, reaching the most unfavorable securities in Coefficient of Uniformity (80 %), Uniformity of Distribution (78 %), Efficiency of Discharge (72 %) and Appropriately Irrigated Area (44 %) when the machine is located perpendicular to the direction of wind, that indicates the convenience of considering the position of the machine in relation to the wind during the evaluation process in order to achieve a better interpretation of the observed results. [ABSTRACT FROM AUTHOR]

This study presents a pipe failure analysis that aims to identify key factors affecting pipe failure in a pilot study area (PSA). For this purpose, pipe failures that occurred in the PSA were recorded for 2 years. Recorded pipe failures were integrated into the existing geographical information systems of the PSA and then visualized. Then, the logistic regression model that calculates failure probability with unbalanced and small- and medium-sized data was performed to analyze pipe failures. Pipe material, age, diameter, burst pressure, and average water pressure are the factors used in the study. The developed model achieved a success rate of 70.1%, suggesting that it can predict a considerable portion of pipe failures with a relatively satisfactory performance. Findings show that the failure probability of pipes with an age greater than 20 years is 1.675 times higher than that of pipes with an age less than 20 years. Moreover, polyvinyl chloride pipes are 5.265 times and high-density polyethylene pipes are 9.027 times more likely to fail than ductile pipes. Further research should delve into the impacts of the number of service connections, pipe lengths, and traffic load on pipe failures. HIGHLIGHTS Pipe failure analysis is a key to implementing asset management strategies.; Logistic regression allows analysis with unbalanced and small- and medium-sized data, which is the case for many water utilities.; The developed model achieved a success rate of 70.1%, indicating that a significant proportion of pipe failures can be predicted with relatively satisfactory performance.;

Copyright of Journal of Water Resources / Recursos Hídricos is the property of Associacao Portuguesa dos Recursos Hidricos and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Optimizing the management of hydraulic infrastructures that support water supply, wastewater, and stormwater drainage can increase the efficiency of these systems. A framework for operational management of urban water systems allows for robust management, which contributes to the system's overall resilience. A methodology has been structured to support the decision-making process of managing entities. The methodology for the operational management of hydraulic infrastructures incorporates concepts of asset management, risk management, and technical management. It is organized into three operational areas (assessment, operation, and intervention) and aims to increase the efficiency of managing entities. Two cases were used to implement the aforementioned methodology—the Arouca Water Supply System (SAA-Arouca) and the Trofa Wastewater Drainage System (SAR-Trofa), both under the responsibility of Águas do Norte, S.A. In SAA-Arouca. There was a particularly significant reduction in the system input volume (purchased the first level) and the number of pipe busts observed in the subsequent period after the implementation of the methodology. Regarding the SAR-Trofa, the application of the methodology focused particularly on improper inflows (rainwater and others). The proposals for this system mainly aim at reducing the volumes collected by the drainage networks (in low-level infrastructures) and delivering them to different high-level infrastructures. [ABSTRACT FROM AUTHOR]

Copyright of News of Kazakhstan Science / Novosti nauki Kazahstana is the property of NCSTE (JSC National Center for State Scientific and Technical Evaluations) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Adequate and sustainable supply of potable water in urban areas of developing countries is often a challenge. This study assessed the performance of the water supply system in Muke Turi town, Oromia, Ethiopia. The Water Geospatial Engineering Modeling System (WaterGEMS) model was used for hydraulic analysis of the distribution network. The water losses were determined by different indicators including non-revenue water (NRW), losses per pipe connection (LPC), losses per main pipe length (LMPL), unavoidable annual real losses (UARL), and infrastructure leakage index (ILI). The water supply coverage of the town was found as 43.34%, which is considerably low. From the hydraulic analysis, the velocity of flow in 54.2% of the pipe and pressure at 60% of the nodes were found within the recommended ranges. The NRW was estimated at 37.61%, which is above the acceptable limit. Of which, the real losses are the major ones with 37.14%. Moreover, the LPC and LMPL were found to be 298 l/d and 29,709 l/km/d, respectively, which are again above the recommended limits. Based on ILI, the annual real losses were estimated to be 4.31 times the UARL. Finally, it was concluded that access to water in the town is inadequate which is exacerbated by high losses. HIGHLIGHTS The level of performance of Muke Turi Town water supply system was assessed.; WaterGEMS hydraulic model was employed to simulate the water distribution network.; The water supply coverage and hydraulic performance of the system were found low.; The supply–demand gap and the water losses are high.; To improve the performance of the system, equitable distribution, service management, and control of losses need utmost attention.;

Water supply system is an important infrastructure that needs improvement in water distribution networks efficiency, along with energy consumption and water losses. DMA Kalipuro 5 is formed to improve the management of water distribution system by monitoring the water flows into the district. This program is supported by pressure management, repairs, active leakage control, and asset management. Water balance is the first step to reduce the water losses. From the water balance of DMA Kalipuro 5 calculated in January and September 2022, the percentage of water losses decreases 7,02%, from 62,55% to 55,53%. The percentage of physical water losses also decreases 7,06%, from 62,32% to 55,26%. Pressure management is conducted in order to reduce the physical water losses by installing pressure reducing valve (PRV). From the simulation of existing water distribution network, installing PRV can reduce the highest pressure from 108,82 meters to 58,42 meters. [ABSTRACT FROM AUTHOR]

To improve water use efficiency and productivity, particularly in irrigated areas, reliable water accounting methodologies are essential, as they provide information on the status and trends in irrigation water availability/supply and consumption/demand. At the collective irrigation system level, irrigation water accounting (IWA) relies on the quantification of water fluxes from the diversion point to the plants, at both the conveyance and distribution network and the irrigated field level. Direct measurement is the most accurate method for IWA, but in most cases, there is limited metering of irrigation water despite the increasing pressure on both groundwater and surface water resources, hindering the water accounting procedures. However, various methodologies, tools, and indicators have been developed to estimate the IWA components, depending on the scale and the level of detail being considered. Another setback for the wide implementation of IWA is the vast terminology used in the literature for different scales and levels of application. Thus, the main objectives of this review, which focuses on IWA for collective irrigation services, are to (i) demonstrate the importance of IWA by showing its relationship with water productivity and water use efficiency; (ii) clarify the concepts and terminology related to IWA; and (iii) provide an overview of various approaches to obtain reliable data for the IWA, on the demand side, both at the distribution network and on-farm systems. From the review, it can be concluded that there is a need for reliable IWA, which provides a common information base for all stakeholders. Future work could include the development of user-friendly tools and methodologies to reduce the bridge between the technology available to collect and process the information on the various water accounting components and its effective use by stakeholders. [ABSTRACT FROM AUTHOR]

Water losses in water distribution systems reach significant rates depending on the network characteristics. Various methods, which have initial investment and operating costs, have been applied to reduce these losses. Therefore, appropriate and applicable methods should be preferred by considering the network characteristics. The aim of this study is to determine the economic loss level with an optimization algorithm for utilities with different network characteristics, water production, operating costs and institutional capacity. Three pilot utilities with different system characteristics and water loss components were selected as application areas. The non-revenue water rates are currently calculated as 57%, 50% and 37%, respectively. The economic loss levels in the pilot utilities were calculated as 29%, 16% and 23% with the optimization model. Moreover, the most appropriate methods to be applied according to the conditions of the utilities were determined in order to reach these defined economic loss levels. It is thought that the results obtained from this study will be a reference for the development of sustainable water loss management strategies and their implementation in the field. HIGHLIGHTS The economic loss level was analyzed with an optimization algorithm.; The economically recoverable loss volume was determined.; The economic loss levels were defined with different networks/system characteristics.; The developed model was tested with field data.; The most suitable water loss prevention methods were determined.;

Water losses due to leakage are a pernicious problem for water utilities. Understanding and quantifying Non-Revenue Water (NRW) and water loss components is the first step in the management of urban water losses. Hydraulic modeling is a powerful tool to predict the impacts of different management scenarios on the hydraulics of the Water Distribution Network (WDN). The water distribution network (WDN) can be divided into a number of District Meter Areas (DMAs) with suitable sizes in order to apply pressure management. In this study, the Fixed Area Variable Area Discharge (FAVAD) concept and the number of leaks were analyzed for a number of water network pressure management areas in the city of Bendjerrah – the district of Guelma, Algeria. The analysis identified some anomalies concerning the parameters of some networks; especially those related to leakage exponent N1 values greater than 1.5. The approach used in this framework is based on the estimation of the leakage from the Minimum Night Flow (MNF) and the burst frequency of Average Zonal Pressure (AZP). After the use of this approach and the calibration procedure using the Epanet-calibrator on real District Meter Areas, the obtained results are very close to the real state of the network. In addition, this paper studies the possibility of explicitly incorporating the variation of the leakage zone in the hydraulic modeling of the water distribution systems. The results show that the power equation leakage exponent N1 estimates the total system leakage with an error of up to 20%. From the Minimum Night Flow, obtained by using the South African Night Flow (SANFLOW) practical tool, it was found that the actual losses calculated for sectors 1, 2, and 3 are respectively 25%, 45%, and 30%.

Copyright of Journal of Engineering (17264073) is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The detection of leakages in Water Distribution Networks (WDNs) is usually challenging and identifying their locations may take a long time. Current water leak detection methods such as model-based and measurement-based approaches face significant limitations that impact response times, resource requirements, accuracy, and location identification. This paper presents a method for determining locations in the WDNs that are vulnerable to leakage by combining six leakage-conditioning factors using logistic regression and vulnerability analysis. The proposed model considered three fixed physical factors (pipe length per junction, number of fittings per length, and pipe friction factor) and three varying operational aspects (drop in pressure, decrease in flow, and variations in chlorine levels). The model performance was validated using 13 district metered areas (DMAs) of the Sharjah Electricity and Water Authority (SEWA) WDN using ArcGIS. Each of the six conditioning factors was assigned a weight that reflects its contribution to leakage in the WDNs based on the Analytic Hierarchy Process (AHP) method. The highest weight was set to 0.25 for both pressure and flow, while 0.2 and 0.14 were set for the chlorine and number of fittings per length, respectively. The minimum weight was set to 0.08 for both length per junction and friction factor. When the model runs, it produces vulnerability to leakage maps, which indicate the DMAs' vulnerability classes ranging from very high to very low. Real-world data and different scenarios were used to validate the method, and the areas vulnerable to leakage were successfully identified based on fixed physical and varying operational factors. This vulnerability map will provide a comprehensive understanding of the risks facing a system and help stakeholders develop and implement strategies to mitigate the leakage. Therefore, water utility companies can employ this method for corrective maintenance activities and daily operations. The proposed approach can offer a valuable tool for reducing water production costs and increasing the efficiency of WDN. [ABSTRACT FROM AUTHOR]

Apparent losses and real losses are two main components of water losses in water supply systems (WSSs). Apparent losses are caused by water meter inaccuracies, illegal consumption, and data handling errors whereas real losses are associated with leakage, pipe bursts and overflow from storage tanks. In well managed WSSs, apparent losses mainly result from inaccuracies of water meters. Performance of water meters is affected from many factors such as meter type, class, size and age, installation, and water consumption profile. In this study, new and used multi-jet type water meters, which is one of the most widely installed water meter type, were tested under different flow rates in a laboratory setup for performance evaluation. Starting flow rates and metering errors of new and used multi-jet water meters under varying flow rates were tested. Average starting flow rate for the new multi-jet (MJ-N) water meters is determined as 7.02 l/h whereas the multi-jet water meters with an age of more than 9 years (MJ-3) old have the highest starting flow rate with an average value of 40.18 l/h. Meter degradation for average starting flow rates shows an almost linear trend. All tested water meters tend to make more measurement errors at lower flow rates. As measurement errors for ageing meters (MJ-2 and MJ-3) are similar at medium and high flow rates, ageing of meters cannot be described by linear degradation. This study showed that ageing and water consumption profiles have a great impact on water meter performance. An evaluation on ageing effects on the accuracy of water meters is provided in this study. [ABSTRACT FROM AUTHOR]

Irrigation canal network problems are resulting from insufficient design, execution, and poor operation and maintenance. In this study, an attempt was made to evaluate the main problems of irrigation networks in Egypt and remediation measures for rehabilitation and optimal irrigation for 3.78 million ha. Recent studies, on the other hand, have shown that most of the existing networks, which have been constructed with colossal costs, suffer from various technical and social problems during the construction and operation processes. To achieve this purpose, (i) strategic planning methods and guidelines have been used to analyze and assess the irrigation networks; and (ii) field studies, visits, and organization of main and sub-main committees with stakeholder participation have been carried out, and (iii) review of literary works and holding of workshops have been applied. Based on the outcomes during the workshops and the main committee, all problems of irrigation systems were categorized into six main topics developing irrigation network systems; environmental assessment; improvement of design quality; improvement of supervision and execution; improvement of operation and maintenance; and monitoring of the system. For each topic, the existing problems in the networks were presented separately in the form of a problem diagram and then a target diagram was developed to optimize and modify the networks. An attempt was made to consider the different core criteria and set time priorities (short, medium, and long term) to determine the performance of the proposed executive and research strategies. [ABSTRACT FROM AUTHOR]

The research aims to study the estimation of the volume of water losses from surface streams in each of Lake Habbaniyah، and to achieve this goal the study adopted a descriptive approach to explain the reasons for the increase in the volume of water losses and study the factors affecting them. different، and it was found in general through the research that there are large amounts of surface water wasted through several processes، the most important of which are (leakage – evaporation. Where the latter worked to increase the amount of water losses from surface streams because the amount of evaporation from a water body during a specific period depends on two groups، the first includes climatic factors that carry between its folds، solar radiation، temperature، relative humidity ... etc.) and the second group includes factors related to The nature of water and its characteristics in terms of water quality، water depth، size and shape of water bodies. The results proved that both groups worked directly to increase the amount of water losses and thus led to a decrease in the amount of water in the study area، so this study came as an attempt to clarify the reality of the possibilities available to estimate the volume of water losses in Lake Habbaniyah، and its role in economic evaluation by working to reduce evaporation and shortage rates The occurrence of water، which leads to hitting the existing tourism in that region.

The water scarcity that Iraq suffers from and the low irrigation efficiency in irrigation projects, therefore, it was necessary to evaluate the performance of the irrigation system of the western canal for the Ishaqi irrigation project in Salah al-Din Governorate to determine the water management strategies that can be used to improve the irrigation efficiency in the project. The performance of the field irrigation system was evaluated on two fields of different crops and irrigation methods according to the agricultural reality of the study area in the Western canal for the Al-Ishaqi Irrigation Project in Salah Al-Din Governorate. The fieldwork included measurements of the moisture content before and after irrigation, field capacity, and measuring the inflow of each field using a venturi flume to find the discharge inside the field and measuring the depth of the root during the growing season. The field measurements showed that the actual average water application efficiency for field W1, which is irrigated with the Border irrigation system is 36.1%, and in field W2, which is irrigated with the furrow irrigation system is 26.8%. As for the water distribution efficiency, the average distribution efficiency for fields W1 and W2 was about 98.8% and 98.4%, respectively. Field measurements showed that the actual conveyance efficiency of the western canal is 93.1%. The overall project efficiency for the western canal was 28.3%. The results of this evaluation conducted in the western canal t revealed that farmers are using more water than required, resulting in a large amount of water loss in the fields by deep permeation observed in this study due to inefficient use, poor irrigation schedule, and lack of knowledge and skills sufficient farmers have in managing water.

Microclimate and physiological changes are consequences of the evaporation of water lost during and after irrigation and these losses depend on the application rates and irrigation duration under the center pivot irrigation system. This study analyzed the uniformity of water distribution and estimated water losses for the center pivot irrigation system, using a double row of catch can in the morning, midday and late afternoon. For this purposes multiple linear regression models were developed using the Software package for social science (SPSS) to estimate the water loss under center pivot irrigation system by determining the factors that predominately affect the applied water at Wonj-Shoa, Sugar Estate Ethiopia. The results showed that the center pivot irrigation system exhibited low distribution uniformity in the study area. The average values of coefficient of uniformity (CU) and distribution uniformity (DU), during the morning, midday and late afternoon were, 77% and 63%, 66% and 60%, 80% and 65%, respectively. At all the test times, the distribution uniformity was within the poor performance range. Water loss from the pivot ranged from 1.03% to 7.74%. The study concludes that; air temperature, relative humidity and travel speed of the last tower are the main factors that predominately negatively affect the applied water; hence, all stakeholders, government and managers of the center pivot should operate when the climate demand is low to increase the yield per applied water. This study has significant implications for improving climate resilience using precision irrigation.

One of the main factors contributing to water scarcity is water loss in water distribution systems, which mainly arises from a lack of adequate knowledge in the design process, optimization of water availability, and poor maintenance/management of the system. Thus, from the perspective of sustainable and integrated management of water resources, it is essential to enhance system efficiency by monitoring existing system elements and enhancing network maintenance/management practices. The current study establishes a smart water grid (SWG) with a digital twin (DT) for a water infrastructure to improve monitoring, management, and system efficiency. Such a tool allows live monitoring of system components, which can analyze different scenarios and variables, such as pressures, operating devices, regulation of different valves, and head-loss factors. The current study explores a case study in which local constraints amplify significant water losses. It develops and examines the DT model's application in the Gaula water distribution network (WDN) in Madeira Island, Portugal. The developed methodology resulted in a significant potential reduction in real water losses, which presented a huge value of 434,273 m3 (~80%) and significantly improved system efficiency. The result shows a meaningful economic benefit, with savings of about EUR 165k in water loss volume with limiting pressures above the regulatory maximum of 60 m w.c. after the district metered area (DMA) sectorization and the requalification of the network. Hence, only 40% of the total annual volume, concerning the status quo situation, is necessary to supply the demand. The infrastructure leakage index measures the existing real losses and the reduction potential, reaching a value of 21.15, much higher than the recommended value of 4, revealing the great potential for improving the system efficiency using the proposed methodology. [ABSTRACT FROM AUTHOR]

Clandestine connections represent a significant portion of the apparent water losses. The objective of this research work is to propose a systematic approach to inspect sites with possible illegal water consumption more precisely. A case study was conducted in a District Metered Area (DMA) located in the city of Joinville, Southern Brazil, using technical information and consumption history from 1400 consumer units located in this area. The proposed methodology uses the bagging technique called Random Forest, through a machine learning algorithm. With success rates of 88.10% when classifying frauds in the model training phase and 88.20% in the test phase, the obtained model shows great ability to properly classify frauds in the water supply system in the studied DMA. The use of the random forest classification model, combined with the SMOTE technique for data balancing, proves to be a viable technical alternative for the detection of unauthorized water consumption. [ABSTRACT FROM AUTHOR]

Numerous methods and tools have been proposed to manage water losses in water distribution systems. These methods generally involve time-consuming and costly processes. Since the dynamic structure of each system is different, the applicability of the methods should be analyzed before applying the methods. In this study, a novel system is developed to analyze the current condition of utility and to assess the data quality and current implementation level of water loss management (WLM) practices. This system consists of a total of 144 WLM components under eight main categories. Pilot utilities are selected to test the feasibility of the developed model and analyze its behavior in the field. Weaknesses and strengths within the scope of WLM are defined separately for each utility. It was understood that the model developed takes into account the dynamic structure of each utility, is applicable in the field, and presents the current condition in a realistic way. It is thought that the developed model will create a reference, especially for practitioners and decision makers in the field, and will provide important benefits in the scope of WLM. [ABSTRACT FROM AUTHOR]

One of the factors limiting the possibility of the development of urban agglomerations is access to drinking water. Due to progressive climate change, the available water resources are limited. The paper proposes new indicators of limiting the development of agglomerations related to the availability of water resources and the production capacity of water treatment plants, a method for assessing the diversification of water resources (using the Pielou index), and a water loss balance was prepared based on International Water Association (IWA) standards. On the basis of the obtained results, the potential increase in the number of inhabitants indicators (∆PR, ∆PP) and the time for the development of agglomeration indicators (TR, TP), the directions of development of the studied agglomerations in terms of the possibility of water supply were indicated. The main problems were reducing the amount of water losses, appropriate management of the migration policy of the population, and the necessity to look for alternative sources of water. [ABSTRACT FROM AUTHOR]

The main global concern in the energy sector is the substitution of fossil fuels and the mitigation of climate change - the transition to the carbon neutrality of the economy. For the power sector, the main solution for this transition is to use hydro, wind and solar energy sources, which have a high energy potential, including in the Republic of Moldova. Variable renewable energy sources, wind and solar, due to their intermittent nature have a significant impact on the power system and the quality of electricity. The necessary measures to reduce the impact of the variability of these sources are presented. The most appropriate measure would be to use pumped storage hydropower plants. The water losses from their accumulation lakes were appreciated. That constitutes approx. 1 ... 2 m3 /MWh which is considerably lower than the losses from the Thermal Power Plants with steam turbines.

In order to determine water losses in irrigation canals, a systematic approach was developed, consisting of two main components: a seepage simulation model and a hydraulic simulation model. The SEEP/W module of the Geo-Studio software was used to simulate the seepage rate, and the Hydrologic Engineering Center-River Analysis System (HEC-RAS) hydrodynamic model was used for hydraulic simulation. Different operation scenarios were designed to investigate all possible situations in daily operation of water distribution and delivery systems. The seepage simulation results show that the seepage losses were higher at the bottom and corners of the canal, because the hydraulic gradient was affected by the hydraulic load. The hydraulic simulation results show that due to physical and management infrastructure (using non-automated and operator-based regulation structures), operational losses accounted for a significant volume of losses compared to seepage losses. In most operation scenarios, the maximum seepage loss was 10%, and the remaining 90% was related to operational losses. It is concluded that any factor (decrease or increase of inflow to the canal) that causes an increase or decrease of operational losses is ultimately a determining factor in reducing or increasing total losses. Therefore, management approaches should be adopted to improve performance of the system and reduce losses, especially operational losses, by improving the operation methods of water level regulation and off-take structures.

Abstract Constantly developing monitoring systems provide a large amount of raw data. In many cases, the operators of water supply systems (WSS) have already reached their perception limit for analysing information. Therefore, the managing process of the WSS requires quasi-intelligent informatics systems, the main purpose of which is to minimise the WSS operating costs in addition to maintaining the proper water delivery to customers. It can be achieved by the detection of abnormal functioning of WSS operations (leakages, water outages). The standard SCADA monitoring systems, in most cases, are not able to distinguish a significant water leakage and water tank filling process. Such cases occur relatively often in complex water supply systems with many water tanks. The aim of this paper is to present the quasi intelligent method of detecting abnormal WSS functioning, including its concepts and effects after a 3 month period operation. The essence of the detection method is the integration of numerical model (built-in Bentley WaterGEMS software) and SCADA monitoring system. The monitoring data are constantly compared to the simulation results and when accepted accordance limits are exceeded, the appropriate alerts are generated. Such solution cause the WSS operator does not need to analyse SCADA system indications constantly. The additional application of the method enables the detection of essential water leakages.

Abstract Accurate and reliable optimization and simulation of the dam reservoir system to ensure optimal use of water resources cannot be achieved without precise and effective models. Providing insight into reservoir system operation and simulation modeling through a comprehensive overview of the previous studies and expanding research horizons can enhance the potential for accurate and well-designed models. The current research reviews previous studies that have used optimization methods to find optimal operating policies for a reservoir system over the past 20 years. Indeed, successful operating policies cannot be obtained without achieving accurate predictions of the main hydrological parameters in the reservoir system, which are inflow and evaporation. The present study focuses on giving an overview of the applications of AI-based models for predicting reservoir inflow and evaporation. The advantages and disadvantages of both optimization algorithms and predictive models have been summarized. Several recommendations for future research have also been included in the present review paper.

Partitioning of water distribution networks (WDNs) into pressure management areas (PMAs) or district metered areas (DMAs) is the most widely applied method for the efficient management and reduction of real losses (leakages). Although PMA partitioning is a crucial task, most clustering methods are strongly affected by user-defined weighting factors that heavily affect the final outcome while being associated with heavy computational loads, leading to time-consuming applications. In this work, we use hierarchical clustering enriched with topological proximity constraints to develop an approach for the optimal sizing and allocation of PMAs (or DMAs) in water distribution networks that seeks to minimize water leakages while maintaining a sufficient level of hydraulic resilience. To quantify the latter, we introduce a resilience index that accounts for water leakages and nodal heads in pressure-driven and mixed pressure-demand ways, respectively. The strong points of the introduced approach are that (1) it uses the original pipeline grid as a connectivity matrix in order to avoid unrealistic clustering outcomes; (2) it is statistically rigorous and user unbiased as it is based solely on statistical metrics, thus not relying on and/or being affected by user-defined weighting factors; and (3) it is easy and fast to implement, requiring minimal processing power. The effectiveness of the developed methodology is tested in a large-scale application study in four PMAs (namely Boud, Kentro, Panahaiki, and Prosfygika) of the city of Patras in western Greece, which cover the entire city center and the most important part of the urban fabric of Patras, consisting of approximately 202 km of pipeline and serving approximately 58,000 consumers. Due to its simplicity, minimal computational requirements, and objective selection criteria, the suggested clustering approach for WDN partitioning can serve as an important step toward developing useful decision-making frameworks for water experts and officials, allowing for improved management and reduction of real water losses. [ABSTRACT FROM AUTHOR]

Although the quantification of lost water, due to leakages in pressure management areas (PMAs) is a crucial task for all water agencies' financial viability, currently there is no rigorous approach for their parametric modeling including the effect of inlet/operating pressures. In this work we develop a probabilistic model for minimum night flow (MNF) estimation in water distribution networks that: (1) parametrizes the MNF as a function of the network's specific characteristics (topography, length of the pipeline grid, pipe diameters, density of connections etc.), and (2) parametrically describes leakages in individual Pressure Management Areas (PMAs) as a function of the inlet/operating pressures. The effectiveness of the developed model is tested in a large-scale real-world application to 43 PMAs of the water distribution network of the city of Patras in western Greece, which cover an area of approximately 18 km2 with approximately 538 km of pipeline serving more than 150 000 consumers. The strong point of the current methodology is that it allows for confidence interval estimation of the parametrized MNFs, including inlet pressure effects, a strong indicator regarding the level of leakages in PMAs. Thus, the current parametric model can serve as a useful tool for water experts and officials, allowing effective selection of proper leakage reduction technics based on a robust probabilistic approach. [ABSTRACT FROM AUTHOR]

The central part of Chile has been in severe unprecedented drought for more than ten years, becoming a water-stressed area. ESVAL, one of the main water utilities in the Chilean water sector, is responsible for delivering potable water to the population and securing long-term supply in the vast majority of this area. In order to achieve this goal, ESVAL is implementing different measures, with pressure management being one of them. This paper aims to describe the works executed in La Calera city to implement a new advanced pressure management scheme on an existing pressure-reducing valve with two main targets: reducing leakage and improving the level of service to the customers. The results show that advance pressure management generates a 10.12% reduction in the minimum night flow while, at the same time, helping to improve the level of service to the customers reducing the number of times pressure falls below the minimum target set by ESVAL by 52%. It is concluded that pressure management facilitates quick water savings by optimizing the performance of existing pressure-reducing valves. [ABSTRACT FROM AUTHOR]

This paper describes the development of an integrated approach for water pipe network calibration and lea quantification. The proposed approach provides a practical procedure that merges field measurements and mathematical modeling for leak quantification and network calibration. The use of Evolutionary Algorithms (EA) using both Genetic Algorithms (GA) and Shuffled Complex Evolution – University of Arizona (SCE-UA) to calculate the pinpointed leak outflows well as to identify any faulty meters. Also, by treating pinpointed physical leaks as junction points, the model, via EPAnet connection, calibrates the network and calculates their demands (which is equivalent to physical losses) and estimating pipes roughness factor (CHW) for better network calibration. Besides, throughout the process, the developed model uses GA and SCE-UA but departs from traditional use in using floating-point representations and introducing a new self-adaptive constraint handling function, which yields optimal results in fewer generations (model runs). Two pilot networks are selected, a well-known hypothetical network (Hanoi network) to present the general mathematical model, while a real network (Faisal city network) is used to test the integrated approach. The model integrates EPAnet for the required hydraulic modeling during the simulation and GIS for input data integration and output representation during the whole procedure. The results prove the approach's accuracy and efficiency.

Leakages cause real losses in water distribution systems (WDSs) from transmission lines, storage tanks, networks, and service connections. In particular, the amount of leakage increases in aging networks due to pressure effects, resulting in severe water losses. In this study, various artificial neural network (ANN) models are considered for determining monthly leakage rates and the variables that affect leakage. The monthly data, which are standardized by Z-score for the years 2016–2019, are used in these models by selecting four independent variables that affect the leakage rate regarding district metered areas and pressure metered areas in WDSs. The pressure effects are taken into consideration directly as input. The model accuracy is determined by comparing the predicted and measured data. Furthermore, the leakage rates are estimated by directly modelling the actual data with ANNs. Consequently, it is found that the model results after data standardization are somewhat better than the original nonstandardized data model results when 30 neurons are used in a single hidden layer. The reason for the higher accuracy in the standardized case compared with previous modelling studies is that the pressure effect is taken into consideration. The suggested models improve the model accuracy, and hence, the methodology of this paper supports an improved pressure management system and leakage reduction. HIGHLIGHTS The data standardized by Z-score.; Pressure effect has been directly taken into consideration for the first time.; The model accuracy has been developed by augmenting neurons numbers in a single hidden layer.; The highest accuracy has been achieved with the least input in models.; Pressure and age effect use directly in modelling.;

Swimming pools are a major contributor to water consumption in our community. However, the high water loss associated with filter cleaning is unknown. In this work, we investigate the current procedures for filter backwashing in public swimming pools by questionnaires to owners and managers. Then, we use the collected data to estimate their environmental and economic costs. Besides, we measure several parameters in the field during the process performed in four representative swimming pools. The investigation revealed that the water loss associated with filter cleaning in public swimming pools rises to 5.5 million m3 water per year, which represents an expense of 13.96 million €. Based on our results, the followed protocols were inappropriate in most cases, indicating that even the required water amount would be higher. The most suitable parameters for filter backwashing monitoring were combined chlorine, ammonium, turbidity and chemical oxygen demand (COD). The necessity for specific strategies and legislation for the management of these installations, the treatment of the generated wastewater, as the implementation of different technological solutions to reduce water loss are discussed. HIGHLIGHTS Water loss from filter backwashing in our community is huge.; Current filter backwashing practices are insufficient and should be improved.; The most suitable parameters for filter backwashing monitoring are combined chlorine, ammonium, turbidity and COD.; Official parameters and limits for backwashing monitoring are needed.; Water-saving strategies should include water reuse and technological improvements.;

In this paper, we presented a methodology for efficient and accurate modeling of water losses in hydraulic tunnels under inside internal water pressure, based on multiple linear regression (MLR). The methodology encompasses all steps needed to obtain an adequate mathematical relation between total water losses and relevant measurements in the tunnel, such as reservoir water level, piezometric levels, concrete and water temperatures, size of cracks, etc. Once the data are preprocessed and input variables were chosen, correlation analysis and PCA (principal component analysis) reduction were performed in order to obtain the pool of regression functions. Through an iterative process, according to stepwise regression principles, the most adequate MLR model in terms of accuracy and complexity was chosen. The methodology presented has been validated in modeling water losses in the hydraulic tunnel under the pressure of PSHPP "Bajina Bašta" in the Republic of Serbia. The obtained results have shown significantly better accuracy compared to the results published by other authors, proving that the developed model can be used as a powerful tool in future analyses of tunnel losses and remediation planning. [ABSTRACT FROM AUTHOR]

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