AbstractNumerous 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.
Water losses occurring in distribution systems have effect on the operating cost, water and energy efficiency, service quality, customer satisfaction, maintenance and new resource demand. The ...standard water balance recommended by International Water Association (IWA) were used for defining, analyzing, regularly monitoring the water balance and sub-components, and determining the weakness and strengths of system. Water Utilities in Turkey are required to fill the water balance annually in order to analyze and monitor the performance with the regulation published in year 2014. However, in the use of this table, important problems are experienced due to the lack of technical, technological, personnel and economic conditions, data representing the field are not used and in many cases the real performance of the system is not revealed. In this study, the importance of IWA water balance in water loss management and monitoring system performance is emphasized, and the benefits and advantages are detailed by analyzing the pilot regions. In addition, problems encountered during filling the water balance, mistakes made, incomplete or incorrectly filled data and other problems were discussed. It is thought that this study will constitute a reference for the technical personnel in Utilities for measuring the data, analyzing the components and interpreting the results.
•Biochar reduced runoff volumes and ratios of slopping land.•Biochar decreased the concentrations of N and P in the runoff.•Biochar has induced significant reduction of the nutrients losses.•Biochar ...exhibits a risk of increasing sediment loss under tillage conditions.
The effects of biochar on runoff and loss of soil and nutrients in the subtropical regions of China are rarely documented. Two field experiments, an orchard and a cropland field were set up, involving two treatments: biochar (BC) and no-biochar (NBC). The effects of BC on runoff volumes and ratios, sediment yield and the level of nutrient losses were monitored and evaluated over three years (2014–2016). Results showed that the treatment of BC induced a significant reduction in the runoff and nutrients losses. By plotting the data collected for the BC application, we observed that the average annual runoff decreased by 19–28%, whereas the average annual sediment yield by 11%. The cumulative values of total nitrogen (N) and phosphorus (P) losses were also substantially minimized by the BC treatment compared with the NBC one (P<0.05). However, the average annual concentrations of total N and P losses as obtained from the BC plots (16.21mgL−1 and 0.72–0.99mgL−1) were still high, and exceeding the wastewater discharge standard (N: 15mgL−1 and P: 0.5mgL−1). In addition, under tillage conditions, the BC application led to larger sediments yield (6.5gm−2) in contrast with the NBC treatment (5.5gm−2). In general, these findings can suggest that BC exhibits a vital efficiency in the control of soil erosion process, but there is a risk of increasing sediment loss under tillage conditions, which might need to be made up by combined with biological and agronomic managements such as straw mulching or adding polyacrylamide into soil in order to control further soil erosion.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Sustainable use of water and energy sources is a crucial challenge for smart and resilient urban water infrastructure. At this aim, this study presents a methodology for implementing and selecting ...pumps-as-turbines (PaTs) in water distribution networks (WDNs) to minimise leakage losses and maximise energy recovery. A novel dynamic control algorithm for PaTs is proposed, which optimises the pressure dissipation while granting a minimum pressure head in the network. The digital hydraulic model of a WDN, which incorporates the developed control strategy, outputs the available pressure heads and flow rates of each PaT for an extended period simulation. The entire simulated data series are fed into a new algorithm to select the best machine to be installed to achieve a reliable solution under realistic and varying conditions. Finally, this methodology is applied to a real test case, improving the sustainability and energy efficiency of a mountainous WDN by enhancing the water-energy nexus.
•Novel algorithm for dynamic pressure control in water supply systems simulations.•Innovative algorithm for optimal pumps-as-turbines selection.•Sustainable and efficient water-energy nexus in water distribution systems.•Methodology applied on a digital twin of an existing water supply system.
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A three-dimensional thermal-hydrologic model considering water losses was developed to simulate heat extraction from an enhanced geothermal system (EGS), consisting of an injection well, a production ...well, a reservoir and the surrounding formation. The model was verified by application to Fenton Hill EGS. Based on the model, the influences of some factors on heat extraction were analyzed. As surrounding formation permeability increases, there are more water losses from the reservoir to the surrounding formation, leading to decreased heat extraction rate. When the two wells approach the edge of the reservoir, heat extraction is restrained, indicating that the two wells should be located about 20–25 m from the edge of the reservoir. Enlarged reservoir volume would not efficiently enhance heat extraction with fixed well layout, suggesting that well layout should be further optimized. Optimized open-hole length is equal to vertical reservoir dimension. Lower production pressure enhances heat extraction, resulting from increased production flow rate and decreased water loss rate. For each factor, it is concluded that thermal breakthrough time mainly depends on production flow rate and water loss rate, showing the important effect of water losses. The results of this paper can offer some suggestions to optimize the EGS performance.
•As surrounding formation permeability increases, heat extraction rate decreases.•When the two wells approach the edge of the reservoir, heat extraction is restrained.•Enlarged reservoir volume would not enhance heat extraction with fixed well layout.•Open-hole length is optimized, and low production pressure enhances heat extraction.•Thermal breakthrough time mainly depends on production flow rate and water loss rate.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
The results of the analysis of water utility performance studies based on data envelopment analysis (DEA) can be very sensitive to the methodological approach and the variables employed. This study ...investigates approaches and variables for developing countries in order to identify an adequate model for universal access. Three models were developed and compared. The first used traditional variables, the second considered the quality of service variables, and the last are expanded on the second by incorporating the realization of the human right to water into efficiency estimation. Methodological approaches comprising the variable returns to scale DEA (most common for developing countries) and slack-based directional distance function (employed in this study) were also compared. The case study of 77 Brazilian water utilities suggests that a model that incorporates the objective of universal access in the efficiency estimation changes substantialy utility efficiency scores. Therefore, utilities that make investments to reach the universal access can be penalized since traditional models incorporate the expenses, but fail to capture the results. The research conclusions suggest that approaches and variable choices are likely to impact on the analysis results, misrepresenting them regardless of the purpose for using DEA in the study.
•An efficiency assessment model considering sustainability issues is proposed.•A slack-based directional distance function model of DEA was employed.•Inequality in water access is included into DEA analysis for the first time.•The model for universal access can contribute to design incentives in the sector.
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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.
•Optimized irrigation in wheat-maize (W-M) and wheat-soybean (W-S) systems evaluated.•Irrigation efficiency decreased with water inputs; W-S system performed better.•W4 reduced deep percolation by 18.3%− 39.4% while maintaining yield stability.•The W-S system had stable yields and better water use efficiency.
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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.
One of the methods of increasing the availability of drinking water is to reduce water losses in existing water supply systems (WSS). The need to manage water losses in WSS is highlighted in the new ...Directive (EU) 2020/2184 of the European Parliament and of the Council of 16 December 2020 on the Quality of Water Intended for Human Consumption. It was indicated that the main cause of water losses is underinvestment in the maintenance and renovation of network infrastructure. The new legal provisions require a risk assessment to be carried out in the water supply system, taking into account the risk of leaks. The paper presents the concept of estimating the risk of water losses in the water supply network using the three-parameter risk assessment method and risk maps. The framework of the water balance proposed by International Water Association (IWA) were also presented, including the Infrastructure Leakage Index (ILI) for assessment of the water supply system Leakage Performance Category (LPC). The analysis was carried out for a water supply system used by 200,000 inhabitants. The LPC of the system was determined based on the ILI index. Then the water supply network pipes that could potentially be a source of leaks were identified. The analysis of the risk of water losses for the examined pipes allowed to determine which pipes should be first chosen to reduce the risk of water losses, i.e. active search for leaks.
•A new method for assessing the risk of water leaks in the water supply network was proposed (three-parameters risk matrix).•The pipe: diameter, material, age, pressure and failure index was identified as a parameters influencing the risk of leakage.•The results of the analysis were presented on the risk maps.•The presented risk-based approach is consistent with the new legal provisions for EU Member States.
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Although data exist about the impact of karst soil restoration in some regions and climates, this information is lacking in the sub-humid Brazilian savannah. Runoff plots with distinct soil covers ...(bare soil, and ecologically restored areas with native species) were installed over a Lithic entisol on a karst slope of the Brazilian savanna (Cerrado), where runoff, erosion, and soil water balance were monitored during 3 hydrologic years. Mean runoff and erosion in the ecologically restored areas decreased from 546 mm yr−1 to 360 mm yr−1, and from 34 Mg ha-1yr−1 to 5 Mg ha-1yr−1, respectively. Soil loss tolerance was exceeded the bare plot of the Lithic entisol in all three hydrologic years. In the third year, erosion fell below soil loss tolerance in the restored plots, indicating that soil degradation could be effectively reduced with ecological restoration. The runoff and erosion data of the present study was fitted by an exponential relationship developed for non-karst soils of the Cerrado. Soil water balance was improved in the restored plots, increasing infiltration and evapotranspiration, and reducing runoff. The results fill an important information gap in tropical karst science, and could be utilized in similar settings.
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