The time of concentration (ToC) is an important parameter in rainfall−runoff simulation for designing and evaluating an urban drainage system (UDS). There are several lumped and distributed methods available in the literature for estimating the ToC. However, these methods lead to significantly varied values. Therefore, it is imperative to choose an appropriate and best-suited method for estimating the ToC. This study analyses eight lumped approach-based and two distributed approach-based methods for estimating the ToC in an urban area of Gurugram, a satellite city in the National Capital Region (NCR) of Delhi in India. Considering the ToC obtained by the Natural Resource Conservation Service (NRCS) method as the ‘true’ value, the Carter method among lumped methods and the SWDM method between the distributed methods results in ToC values in agreement with the NRCS method. Furthermore, to study the impact of the underestimation or overestimation of ToC on drainage, the system is evaluated in terms of variation in flood volume, duration, peak discharge, and the time to peak for different ToC values. The simulations were carried out by setting the model in SWMM, and it was found that flood volume increases by 4.25 times and the duration increases by 7.25 times if the ToC is increased from 0.1 to 6.14 h. The results infer that ToC estimation methods significantly impact the design and performance of an urban drainage infrastructure.
{"title":"A comparative study of the time of concentration methods for designing urban drainage infrastructure","authors":"Osheen Mehta, M. Kansal, Deepak Singh Bisht","doi":"10.2166/aqua.2022.107","DOIUrl":"https://doi.org/10.2166/aqua.2022.107","url":null,"abstract":"\u0000 The time of concentration (ToC) is an important parameter in rainfall−runoff simulation for designing and evaluating an urban drainage system (UDS). There are several lumped and distributed methods available in the literature for estimating the ToC. However, these methods lead to significantly varied values. Therefore, it is imperative to choose an appropriate and best-suited method for estimating the ToC. This study analyses eight lumped approach-based and two distributed approach-based methods for estimating the ToC in an urban area of Gurugram, a satellite city in the National Capital Region (NCR) of Delhi in India. Considering the ToC obtained by the Natural Resource Conservation Service (NRCS) method as the ‘true’ value, the Carter method among lumped methods and the SWDM method between the distributed methods results in ToC values in agreement with the NRCS method. Furthermore, to study the impact of the underestimation or overestimation of ToC on drainage, the system is evaluated in terms of variation in flood volume, duration, peak discharge, and the time to peak for different ToC values. The simulations were carried out by setting the model in SWMM, and it was found that flood volume increases by 4.25 times and the duration increases by 7.25 times if the ToC is increased from 0.1 to 6.14 h. The results infer that ToC estimation methods significantly impact the design and performance of an urban drainage infrastructure.","PeriodicalId":17666,"journal":{"name":"Journal of Water Supply: Research and Technology-Aqua","volume":"11 3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88985278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mathurin François, Ronald Petit-Homme, E. Mariano‐Neto, Marc-Arthur Petit-Homme, Terencio Rebello de Aguiar Junior
Trees provide services to human beings and protect the environment. This study investigates the causes of the failure of reforestation projects in the North and Northeast departments of Haiti. Two questionnaires with closed- and open-ended questions were used for face-to-face and semi-structured interviews with local and non-local authorities, respectively. The test of proportions was used for the statistical analysis, where a result was considered significant when the p-value was less than 0.05. The results showed that 86.8% of the non-local authorities were used to participating in projects of reforestation in their localities. The lack of follow-up and participation of residents in decisions about the type of trees planted were the main causes of the failure of these projects. The interviewees were accustomed to cutting trees to produce charcoal (95.8%) and enlarging their gardens (70.8%). However, 90.0% of each category would invest in purchasing cleaner cookstoves and stop using charcoal if the government agreed to finance up to 50.0% of such a project. The findings of this research could help both the decision-makers and the Haitian government to understand the causes of the failures of reforestation projects in Haiti and adopt an effective way to reduce deforestation in the country.
{"title":"Causes for reforestation failure in Haiti and residents' willingness to pay for cleaner cookstoves","authors":"Mathurin François, Ronald Petit-Homme, E. Mariano‐Neto, Marc-Arthur Petit-Homme, Terencio Rebello de Aguiar Junior","doi":"10.2166/aqua.2022.058","DOIUrl":"https://doi.org/10.2166/aqua.2022.058","url":null,"abstract":"\u0000 Trees provide services to human beings and protect the environment. This study investigates the causes of the failure of reforestation projects in the North and Northeast departments of Haiti. Two questionnaires with closed- and open-ended questions were used for face-to-face and semi-structured interviews with local and non-local authorities, respectively. The test of proportions was used for the statistical analysis, where a result was considered significant when the p-value was less than 0.05. The results showed that 86.8% of the non-local authorities were used to participating in projects of reforestation in their localities. The lack of follow-up and participation of residents in decisions about the type of trees planted were the main causes of the failure of these projects. The interviewees were accustomed to cutting trees to produce charcoal (95.8%) and enlarging their gardens (70.8%). However, 90.0% of each category would invest in purchasing cleaner cookstoves and stop using charcoal if the government agreed to finance up to 50.0% of such a project. The findings of this research could help both the decision-makers and the Haitian government to understand the causes of the failures of reforestation projects in Haiti and adopt an effective way to reduce deforestation in the country.","PeriodicalId":17666,"journal":{"name":"Journal of Water Supply: Research and Technology-Aqua","volume":"100 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78743906","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The provision of clean water and sanitation has been one of the challenging goals of the Sustainable Development Goals (SDGs) for developing countries like Bangladesh. The southern cities of the country confront the scarcity of fresh and improved water for drinking and sanitation. The study aims to investigate the demand for improved water service among city dwellers and the potential revenue for the water supply authority. The study surveyed 100 households in Khulna city by administering a simple random sampling method. The single-bounded dichotomous choice contingent valuation method revealed that years of schooling, household income, and excessive time in water collection positively affect willingness to pay (WTP) for improved water service. The households are willing to pay US$ 5.05 per month on average for enjoying improved water service, which in turn produces annual revenues of US$ 4.26 million, overriding the current level of revenue by 2.5 times. Additionally, the water supply authority is incurring around US$ 2.14 million of revenue loss annually which can be recovered by supplying improved water to the city households. This study suggests that the government may be able to address the fresh and improved water scarcity in the urban territory by capturing and utilizing the potential revenue efficiently through removing the structural barriers.
{"title":"Willingness to pay for improved water supply service in coastal urban settings: evidence from Khulna, Bangladesh","authors":"Karimul Islam, Rabbani Akter, M. Z. Haider","doi":"10.2166/aqua.2022.061","DOIUrl":"https://doi.org/10.2166/aqua.2022.061","url":null,"abstract":"\u0000 The provision of clean water and sanitation has been one of the challenging goals of the Sustainable Development Goals (SDGs) for developing countries like Bangladesh. The southern cities of the country confront the scarcity of fresh and improved water for drinking and sanitation. The study aims to investigate the demand for improved water service among city dwellers and the potential revenue for the water supply authority. The study surveyed 100 households in Khulna city by administering a simple random sampling method. The single-bounded dichotomous choice contingent valuation method revealed that years of schooling, household income, and excessive time in water collection positively affect willingness to pay (WTP) for improved water service. The households are willing to pay US$ 5.05 per month on average for enjoying improved water service, which in turn produces annual revenues of US$ 4.26 million, overriding the current level of revenue by 2.5 times. Additionally, the water supply authority is incurring around US$ 2.14 million of revenue loss annually which can be recovered by supplying improved water to the city households. This study suggests that the government may be able to address the fresh and improved water scarcity in the urban territory by capturing and utilizing the potential revenue efficiently through removing the structural barriers.","PeriodicalId":17666,"journal":{"name":"Journal of Water Supply: Research and Technology-Aqua","volume":"358 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76922223","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Compliance with the Water Framework Directive has not yet been met by Albania, and further efforts are needed to achieve this goal, including the implementation of an extensive programme of monitoring of surface and groundwater bodies. Benthic macroinvertebrates are an integrated element of this monitoring programme whose results are being used to assess the achievement of the Water Framework Directive objectives. This study has been carried out strictly following protocols and methodologies of the Water Framework Directive. The biological assessment took place in 2017 at 11 monitoring stations along the Drin River in Albania. Sampled specimens have been used to assess the water quality along the Drin River Basin through a set of indices’ calculations per each group of indicators. A total of 41 benthic invertebrate taxa were used to calculate the biotic indices, finding out only 3 monitoring stations with a good status of water out of 11 monitoring stations assessed in our study; water quality in 8 monitoring stations is classified as a moderate or poor status. Statistical analysis has been carried out to identify the trend of benthic invertebrates from one sampling point to another and the factors influencing the similarity between monitoring stations and benthic invertebrate families.
{"title":"Preliminary data on water quality using benthic macroinvertebrates as quality indicators: a case study in the Drin River Basin, Albania","authors":"E. Keci, Bledar Pepa, A. Paparisto, P. Lazo","doi":"10.2166/aqua.2022.084","DOIUrl":"https://doi.org/10.2166/aqua.2022.084","url":null,"abstract":"\u0000 Compliance with the Water Framework Directive has not yet been met by Albania, and further efforts are needed to achieve this goal, including the implementation of an extensive programme of monitoring of surface and groundwater bodies. Benthic macroinvertebrates are an integrated element of this monitoring programme whose results are being used to assess the achievement of the Water Framework Directive objectives. This study has been carried out strictly following protocols and methodologies of the Water Framework Directive. The biological assessment took place in 2017 at 11 monitoring stations along the Drin River in Albania. Sampled specimens have been used to assess the water quality along the Drin River Basin through a set of indices’ calculations per each group of indicators. A total of 41 benthic invertebrate taxa were used to calculate the biotic indices, finding out only 3 monitoring stations with a good status of water out of 11 monitoring stations assessed in our study; water quality in 8 monitoring stations is classified as a moderate or poor status. Statistical analysis has been carried out to identify the trend of benthic invertebrates from one sampling point to another and the factors influencing the similarity between monitoring stations and benthic invertebrate families.","PeriodicalId":17666,"journal":{"name":"Journal of Water Supply: Research and Technology-Aqua","volume":"530 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80164404","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Suresh, P. Kumari, J. M. Jha, S. Verma, S. Arisutha, P. Lens
This research presents the sonocatalytic degradation of naphthalene from an aqueous medium using a zinc oxide (ZnO) catalyst synthesised by the thermal decomposition method. The present paper also aims to apply the response surface methodology for the evaluation of the effect of different parameters on the degradation rate. The optimum parameters were found to be 50 min of reaction time, 2.2 g/l of the ZnO catalyst mass, 30 °C, 280 V, and 80 mg/l of initial concentration under a constant ultrasonic treatment at 20 kHz and 260 W of power intensity. The elemental composition of the catalyst was as follows: Zn 25.18%, O 37.03%, Mg 3.20%, K 0.83%, Ca 4.05%, N 5.07%, Na 4.13%, Cl 3.43%, and Fe 0.32%. Fourier Transform Infra-Red (FTIR) confirmed the Zn–O bond stretching at 510 cm−1. The degradation efficiency of naphthalene was almost double when the ZnO catalyst was used. The naphthalene degradation rate was a first-order reaction. Analysis of variance (ANOVA) results show that the quadratic model is suitable for the obtained data (P-value = 0.0001) and in an optimal process, performance conditions were set equal to 100%. Regression analysis with a high correlation coefficient (R2 = 0.989) and the model F-value of 6.94 indicated the adequacy of the model. The reusability study revealed that ZnO as a catalyst sustained the catalytic activity over five cycles.
本文研究了用热分解法合成的氧化锌(ZnO)催化剂对萘的声催化降解。本文还旨在应用响应面法评价不同参数对降解率的影响。结果表明，在20 kHz、260 W的恒定超声处理下，反应时间为50 min，催化剂质量为2.2 g/l，反应温度为30℃，反应电压为280 V，初始浓度为80 mg/l。催化剂的元素组成为:Zn 25.18%， O 37.03%， Mg 3.20%， K 0.83%， Ca 4.05%， N 5.07%， Na 4.13%， Cl 3.43%， Fe 0.32%。傅里叶变换红外(FTIR)证实了Zn-O键在510 cm−1处的拉伸。使用ZnO催化剂时，萘的降解效率几乎提高了一倍。萘的降解速率为一级反应。方差分析(ANOVA)结果表明，二次模型适用于所获得的数据(p值= 0.0001)，在最优工艺中，性能条件设置为100%。回归分析显示相关系数较高(R2 = 0.989)，模型f值为6.94，表明模型的充分性。重复使用研究表明，ZnO作为催化剂的催化活性可维持5个循环以上。
{"title":"Sonocatalytic removal of naphthalene from an aqueous solution using ZnO nanoparticles","authors":"S. Suresh, P. Kumari, J. M. Jha, S. Verma, S. Arisutha, P. Lens","doi":"10.2166/aqua.2022.042","DOIUrl":"https://doi.org/10.2166/aqua.2022.042","url":null,"abstract":"\u0000 This research presents the sonocatalytic degradation of naphthalene from an aqueous medium using a zinc oxide (ZnO) catalyst synthesised by the thermal decomposition method. The present paper also aims to apply the response surface methodology for the evaluation of the effect of different parameters on the degradation rate. The optimum parameters were found to be 50 min of reaction time, 2.2 g/l of the ZnO catalyst mass, 30 °C, 280 V, and 80 mg/l of initial concentration under a constant ultrasonic treatment at 20 kHz and 260 W of power intensity. The elemental composition of the catalyst was as follows: Zn 25.18%, O 37.03%, Mg 3.20%, K 0.83%, Ca 4.05%, N 5.07%, Na 4.13%, Cl 3.43%, and Fe 0.32%. Fourier Transform Infra-Red (FTIR) confirmed the Zn–O bond stretching at 510 cm−1. The degradation efficiency of naphthalene was almost double when the ZnO catalyst was used. The naphthalene degradation rate was a first-order reaction. Analysis of variance (ANOVA) results show that the quadratic model is suitable for the obtained data (P-value = 0.0001) and in an optimal process, performance conditions were set equal to 100%. Regression analysis with a high correlation coefficient (R2 = 0.989) and the model F-value of 6.94 indicated the adequacy of the model. The reusability study revealed that ZnO as a catalyst sustained the catalytic activity over five cycles.","PeriodicalId":17666,"journal":{"name":"Journal of Water Supply: Research and Technology-Aqua","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90211925","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Simulation–optimization approaches are useful methods for the assessment of water resource engineering plans and finding the best management policy at the watershed scale. In this study, to find the optimum operation for a reservoir with the purpose of satisfying water demands while meeting the water quantity and quality criteria, a generic reservoir and river basin simulation model (MODSIM) is coupled with the particle swarm optimization (PSO) algorithm leading to construct the PSO–MODSIM model. With the decision variables of the reservoir's monthly releases, the objective function is to maximize the supply for downstream demands while keeping the electrical conductivity (EC) in the river flow lower than a predefined level at the downstream checkpoint, which is a function of the EC in the agricultural return flows. Moreover, a safe flow rate is defined in which the streamflow should not exceed at the checkpoint resulting in mitigation of the submerging lands damage. Results obtained by the PSO–MODSIM model indicate the ability of the proposed simulation–optimization approach for solving the problem of optimal quantity–quality-based water allocation in a reservoir–river system. For instance, the EC at the checkpoint is decreased by 61% in the optimum reservoir operation state comparing the present situation, whereas the municipal and environmental demands are fully met and the agricultural demands are supplied with a desirable reliability satisfaction level.
{"title":"Quantity–quality-based water allocation programming in a reservoir–river system","authors":"A. Ebrahimi, M. Shourian","doi":"10.2166/aqua.2022.056","DOIUrl":"https://doi.org/10.2166/aqua.2022.056","url":null,"abstract":"\u0000 Simulation–optimization approaches are useful methods for the assessment of water resource engineering plans and finding the best management policy at the watershed scale. In this study, to find the optimum operation for a reservoir with the purpose of satisfying water demands while meeting the water quantity and quality criteria, a generic reservoir and river basin simulation model (MODSIM) is coupled with the particle swarm optimization (PSO) algorithm leading to construct the PSO–MODSIM model. With the decision variables of the reservoir's monthly releases, the objective function is to maximize the supply for downstream demands while keeping the electrical conductivity (EC) in the river flow lower than a predefined level at the downstream checkpoint, which is a function of the EC in the agricultural return flows. Moreover, a safe flow rate is defined in which the streamflow should not exceed at the checkpoint resulting in mitigation of the submerging lands damage. Results obtained by the PSO–MODSIM model indicate the ability of the proposed simulation–optimization approach for solving the problem of optimal quantity–quality-based water allocation in a reservoir–river system. For instance, the EC at the checkpoint is decreased by 61% in the optimum reservoir operation state comparing the present situation, whereas the municipal and environmental demands are fully met and the agricultural demands are supplied with a desirable reliability satisfaction level.","PeriodicalId":17666,"journal":{"name":"Journal of Water Supply: Research and Technology-Aqua","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82237903","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The presence of toxic algae, such as Microcystis aeruginosa (MA), in drinking water treatment plants (DWTPs) would contribute to algal organic matter (AOM) as precursors toward disinfection by-products (DBPs). Electrocoagulation–flotation (ECF) has shown promising performance in minimizing algal cells from water and dissolved AOM. This study aimed to investigate the effect of current density (CD) and pH on alumina (Al)-based ECF for removing MA cell and DBPs precursors from cyanobacteria-laden water. The performance of Al-based ECF was evaluated at various CD and pH conditions within 20 min. In addition, the total halogenated DBPs formation of the treated suspension after ECF was quantified. At pH 8, the ECF process with 5 mA/cm2 exhibits the most significant reductions in MA cell and soluble AOM, accounting for 97 and 56%, respectively. Additionally, the precursors of trihalomethanes (THMs) and haloketones (HKs) can be effectively removed with flotation despite their significant release at EC. The tremendous reduction of humic acid-like (HAL) substances in extracellular organic matter (EOM) fraction by ECF leads to the minimized THMs formation potential. In summary, Al-based ECF at pH 8 is effective to remove cyanobacteria and minimize the precursors of regulated THMs along with an insignificant reduction in regulated haloacetic acids (HAAs) precursors.
{"title":"Minimization of halogenated disinfection by-product precursors by Al-based electrocoagulation–flotation (ECF) toward cyanobacteria-laden water","authors":"Jr-Lin Lin, Fahrudin Sidik, Shyh-fang Kang","doi":"10.2166/aqua.2022.065","DOIUrl":"https://doi.org/10.2166/aqua.2022.065","url":null,"abstract":"\u0000 The presence of toxic algae, such as Microcystis aeruginosa (MA), in drinking water treatment plants (DWTPs) would contribute to algal organic matter (AOM) as precursors toward disinfection by-products (DBPs). Electrocoagulation–flotation (ECF) has shown promising performance in minimizing algal cells from water and dissolved AOM. This study aimed to investigate the effect of current density (CD) and pH on alumina (Al)-based ECF for removing MA cell and DBPs precursors from cyanobacteria-laden water. The performance of Al-based ECF was evaluated at various CD and pH conditions within 20 min. In addition, the total halogenated DBPs formation of the treated suspension after ECF was quantified. At pH 8, the ECF process with 5 mA/cm2 exhibits the most significant reductions in MA cell and soluble AOM, accounting for 97 and 56%, respectively. Additionally, the precursors of trihalomethanes (THMs) and haloketones (HKs) can be effectively removed with flotation despite their significant release at EC. The tremendous reduction of humic acid-like (HAL) substances in extracellular organic matter (EOM) fraction by ECF leads to the minimized THMs formation potential. In summary, Al-based ECF at pH 8 is effective to remove cyanobacteria and minimize the precursors of regulated THMs along with an insignificant reduction in regulated haloacetic acids (HAAs) precursors.","PeriodicalId":17666,"journal":{"name":"Journal of Water Supply: Research and Technology-Aqua","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81962434","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kun Du, Bang Xiao, Z. Song, Yue Xu, Zhiyi Tang, Wei Xu, Huanfeng Duan
A differential evolution (DE) algorithm has been demonstrated to be the most powerful evolutionary algorithm (EA) to optimally design water distribution systems (WDSs), but issues such as slow convergence speed, limited exploratory ability, and parameter adjustment remain when used for large-scale WDS optimization. This paper proposes a novel self-adaptation and sorting selection-based differential evolutionary (SA-SSDE) algorithm that can solve large-scale WDS optimization problems more efficiently while having the greater ability to explore global optimal solutions. The following two unique features enable the better performance of the proposed SA-SSDE algorithm: (1) The DE/current-to-pbest/n mutation and sorting selection operators are used to speed up the convergence and thus improve the optimization efficiency; (2) the parameter adaptation strategy in JADE is introduced and modified to cater for WDS optimization, and it is capable of dynamically adapting the control parameters (i.e., F and CR values) to the fitness landscapes characteristic of larger-scale WDS optimization problems, allowing for greater exploratory ability. The proposed SA-SSDE algorithm found new best solutions of $7.068 million, €1.9205 million, and $30.852 million for three well-known large networks (ZJ164, Balerma454, and Rural476), having the convergence speed of 1.02, 1.92, and 5.99 times faster than the classic DE, respectively. Investigations into the searching behavior and the control parameter evolution during optimization are carried out, resulting in a better understanding of why the proposed SA-SSDE algorithm outperforms the classic DE, as well as the guidance for developing more advanced EAs.
{"title":"A novel self-adaptation and sorting selection-based differential evolutionary algorithms applied to water distribution system optimization","authors":"Kun Du, Bang Xiao, Z. Song, Yue Xu, Zhiyi Tang, Wei Xu, Huanfeng Duan","doi":"10.2166/aqua.2022.174","DOIUrl":"https://doi.org/10.2166/aqua.2022.174","url":null,"abstract":"\u0000 A differential evolution (DE) algorithm has been demonstrated to be the most powerful evolutionary algorithm (EA) to optimally design water distribution systems (WDSs), but issues such as slow convergence speed, limited exploratory ability, and parameter adjustment remain when used for large-scale WDS optimization. This paper proposes a novel self-adaptation and sorting selection-based differential evolutionary (SA-SSDE) algorithm that can solve large-scale WDS optimization problems more efficiently while having the greater ability to explore global optimal solutions. The following two unique features enable the better performance of the proposed SA-SSDE algorithm: (1) The DE/current-to-pbest/n mutation and sorting selection operators are used to speed up the convergence and thus improve the optimization efficiency; (2) the parameter adaptation strategy in JADE is introduced and modified to cater for WDS optimization, and it is capable of dynamically adapting the control parameters (i.e., F and CR values) to the fitness landscapes characteristic of larger-scale WDS optimization problems, allowing for greater exploratory ability. The proposed SA-SSDE algorithm found new best solutions of $7.068 million, €1.9205 million, and $30.852 million for three well-known large networks (ZJ164, Balerma454, and Rural476), having the convergence speed of 1.02, 1.92, and 5.99 times faster than the classic DE, respectively. Investigations into the searching behavior and the control parameter evolution during optimization are carried out, resulting in a better understanding of why the proposed SA-SSDE algorithm outperforms the classic DE, as well as the guidance for developing more advanced EAs.","PeriodicalId":17666,"journal":{"name":"Journal of Water Supply: Research and Technology-Aqua","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81138006","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yiran Wang, Xiao-dong Yu, HangXiao Qin, Nan Cheng, Chao Yu
The pressure surges for water filling in deep stormwater storage tunnels (DSSTs) with entrapped air-pockets seriously threaten the safety of pipeline structures and even lead to the destruction of urban water infrastructure. Hence, this paper develops a volume of fluid (VOF) model to study pressure surges in a two shafts and one tunnel system. Research works under different initial air-pocket parameters are carried out, while the VOF model is verified by the empty tunnel water filling experiment in the same system. The results show that the maximum pressure increases with an initial length/diameter ratio decrease or air volume fraction increase. Also, the extreme pressure with entrapped air-pocket at a certain scale can reach 1.6 times the static pressure (30 m). With the increase of initial air volume fraction, the frequency of pressure surges slows down, while the maximum pressure gradually increases and approaches a specific value within a fixed air volume fraction range (0.2–5.0%). The maximum pressure of air-pocket at different initial positions shows a downward trend from the middle of the tunnel to two sides, while the pressure of the air-pocket near a higher shaft will be slightly higher. The proposed model can be extended to systems with multiple shafts or air-pockets, and the conclusions have reference significance for structure design and water filling control in the DSST.
{"title":"Analysis of pressure surges for water filling in deep stormwater storage tunnels with entrapped air-pocket using a VOF model","authors":"Yiran Wang, Xiao-dong Yu, HangXiao Qin, Nan Cheng, Chao Yu","doi":"10.2166/aqua.2022.039","DOIUrl":"https://doi.org/10.2166/aqua.2022.039","url":null,"abstract":"\u0000 The pressure surges for water filling in deep stormwater storage tunnels (DSSTs) with entrapped air-pockets seriously threaten the safety of pipeline structures and even lead to the destruction of urban water infrastructure. Hence, this paper develops a volume of fluid (VOF) model to study pressure surges in a two shafts and one tunnel system. Research works under different initial air-pocket parameters are carried out, while the VOF model is verified by the empty tunnel water filling experiment in the same system. The results show that the maximum pressure increases with an initial length/diameter ratio decrease or air volume fraction increase. Also, the extreme pressure with entrapped air-pocket at a certain scale can reach 1.6 times the static pressure (30 m). With the increase of initial air volume fraction, the frequency of pressure surges slows down, while the maximum pressure gradually increases and approaches a specific value within a fixed air volume fraction range (0.2–5.0%). The maximum pressure of air-pocket at different initial positions shows a downward trend from the middle of the tunnel to two sides, while the pressure of the air-pocket near a higher shaft will be slightly higher. The proposed model can be extended to systems with multiple shafts or air-pockets, and the conclusions have reference significance for structure design and water filling control in the DSST.","PeriodicalId":17666,"journal":{"name":"Journal of Water Supply: Research and Technology-Aqua","volume":"41 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87253472","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Abraham, K. Venugopal, R. Arunkumar, S. K. Pramada
The application of system dynamics techniques is gaining significance and is much needed for an effective management of the depleting water resources in a dynamically complex region and considers it as the feedback from the system. The present study deals with the application of a system dynamic approach to simulate a chain of four tanks in the Guduvanchery watershed, Tamil Nadu, India. Standard data-driven models cannot be effectively used due to a lack of quality data for ungauged basins. VENSIM was used for the system dynamic simulation to assess water availability for the sustainable management of water resources. Inflow into the four tanks, net losses in each tank, and crop water requirement were given as inputs into VENSIM. Along with different models, an extensive field survey was carried out to quantify each input component. Based on system dynamics simulation, only 28% of the total available water is used for irrigation and the rest is wasted due to evaporation, transition loss, and spill from the tanks. It was found that there was approximately 5.46 MCM of surface water available in the watershed, and it will be able to supply the domestic demand of the watershed of 0.672 MCM in addition to the irrigation requirement.
{"title":"Simulation of chain of tanks to augment water supply: a case study from Tamil Nadu","authors":"M. Abraham, K. Venugopal, R. Arunkumar, S. K. Pramada","doi":"10.2166/aqua.2022.038","DOIUrl":"https://doi.org/10.2166/aqua.2022.038","url":null,"abstract":"\u0000 The application of system dynamics techniques is gaining significance and is much needed for an effective management of the depleting water resources in a dynamically complex region and considers it as the feedback from the system. The present study deals with the application of a system dynamic approach to simulate a chain of four tanks in the Guduvanchery watershed, Tamil Nadu, India. Standard data-driven models cannot be effectively used due to a lack of quality data for ungauged basins. VENSIM was used for the system dynamic simulation to assess water availability for the sustainable management of water resources. Inflow into the four tanks, net losses in each tank, and crop water requirement were given as inputs into VENSIM. Along with different models, an extensive field survey was carried out to quantify each input component. Based on system dynamics simulation, only 28% of the total available water is used for irrigation and the rest is wasted due to evaporation, transition loss, and spill from the tanks. It was found that there was approximately 5.46 MCM of surface water available in the watershed, and it will be able to supply the domestic demand of the watershed of 0.672 MCM in addition to the irrigation requirement.","PeriodicalId":17666,"journal":{"name":"Journal of Water Supply: Research and Technology-Aqua","volume":"12 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75395670","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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