technical paper
Irrigation network management
Arezou Mokhtari hesari; Alireza Nemati
Abstract
Extended AbstractIntroductionThe majority of agricultural areas worldwide are managed using traditional surface irrigation methods. However, these methods face significant challenges, including inefficient water use and suboptimal productivity. Given their widespread use and low efficiency, improving ...
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Extended AbstractIntroductionThe majority of agricultural areas worldwide are managed using traditional surface irrigation methods. However, these methods face significant challenges, including inefficient water use and suboptimal productivity. Given their widespread use and low efficiency, improving surface irrigation systems has become essential. In recent decades, numerous initiatives have aimed to enhance the efficiency of irrigation systems and management practices. One such advancement is the development of low-pressure irrigation systems. Studies based on behavioral theories examining farmers’ adoption of irrigation technologies have identified several influential factors. Accordingly, this study aims to explain the role of technology ease of use and farmers’ self-efficacy in influencing their behavior toward adopting and using modern low-pressure irrigation systems. Materials and MethodsThe method of this research follows a quantitative paradigm. In terms of purpose, it is applied research, and in terms of data collection, it is descriptive research conducted through a survey. In total, 112,010 farmers in East Azerbaijan Province formed the study population, and a sample of 393 was selected using the Cochran formula through multi-stage sampling. The main data collection tool was a researcher-designed questionnaire consisting of three parts: the first part relates to the individual characteristics of the farmers, the second part concerns the characteristics of the exploitation system, and the third part includes items related to the main variables. The face and content validity of the questionnaire were confirmed by professors and subject matter experts. The reliability of the research instrument was determined using Cronbach’s alpha, and construct validity was assessed through convergent validity using confirmatory factor analysis. SPSS 20 and AMOS 21 software were used for data analysis.Results The measurement and structural model analyses indicated that model fit was acceptable across multiple indices and that the hypothesized relationships among the variables were logically consistent. Hypothesis testing revealed that all proposed relationships were statistically significant. Specifically, there was a positive and significant relationship between the perceived ease of use of the low-pressure irrigation system and farmers’ willingness to adopt it. Additionally, farmers’ self-efficacy was found to be significantly associated with their willingness to use the technology. Overall, structural equation modeling showed that ease of use and self-efficacy together explained 60% of the variance in farmers’ willingness to adopt low-pressure irrigation systems, with ease of use emerging as the stronger predictor. ConclusionsThis study investigated the factors influencing farmers’ adoption of low-pressure irrigation systems. Specifically, it examined the effects of perceived ease of use of the technology and farmers’ self-efficacy on their willingness to adopt such systems. The findings confirmed that both factors significantly influence adoption, with ease of use playing a particularly strong role. When the equipment, connections, and maintenance of the irrigation system are simple to operate and learn, farmers are more likely to adopt low-pressure irrigation. Additionally, farmers’ confidence in their ability to implement water conservation strategies enhances their conservation behavior. In other words, effective water conservation depends on farmers’ understanding and belief in their own capabilities.
Original Article
Hydraulic
Saeed Akbari Zade; Ehsan Fadaei-Kermani; Mahnaz Ghaeini-Hessaroeyeh
Abstract
Extended AbstractIntroductionUrban sewage collection systems in areas with rugged topography present significant hydraulicchallenges. Steep slopes and substantial elevation differences generate high kinetic energy in the flow.Without proper control, this excess energy leads to adverse consequences, including ...
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Extended AbstractIntroductionUrban sewage collection systems in areas with rugged topography present significant hydraulicchallenges. Steep slopes and substantial elevation differences generate high kinetic energy in the flow.Without proper control, this excess energy leads to adverse consequences, including erosion and degradationof the channel bed and walls. Further issues may involve structural damage and vibrations induced by highenergyflow, the entrainment of large volumes of air due to free-falling sewage, and the potential for waterhammer in closed systems. To address these challenges, vortex drop structures have been introduced as anefficient engineering solution. These structures establish a controlled vortex flow pattern within a verticalshaft, thereby dissipating the incoming flow's excess energy in an effective and manageable manner.MethodologyIn the present study, a physical model of a vortex drop structure was constructed to investigate itshydraulic performance, including the spiral inlet and the shaft. Furthermore, since the structure's performancein flow energy dissipation is significantly influenced by the upstream and downstream hydraulic conditionsand geometry, the rate of flow energy dissipation by the structure was measured.A 1:10 scale physical model of the East Tehran Sewer Vortex Drop Structure was constructed in theHydraulic Structures Laboratory of Shahid Bahonar University of Kerman, Iran. The model comprises arectangular approach channel, a tangential vortex inlet, a drop shaft, an energy dissipator, and a rectangularoutlet conduit. In this study, a spiral inlet with different outlet diameters was employed. The inlet channel,with a rectangular cross-section, conveys the flow to the tangential inlet structure. This channel measures0.18 m in width (B) and 0.21 m in height. Downstream of the vortex drop structure, the flow exits via arectangular outlet conduit measuring 0.18 m in width and 0.24 m in height.The model begins with an initial reservoir; upon filling, water enters the structure through the inletchannel. The wall height of the inlet channel is 0.24 m. Four different flow rates were used in this experiment:10.67, 14.55, 19.40, and 25.22 liters per second, respectively.Results and DiscussionIn the present study, the flow behavior within different sections of the vortex drop structure, includingthe inlet channel, the spiral inlet structure, and the outlet channel (energy dissipator), was investigated.Subsequently, the influence of three parameters including: flow rate (Q), inlet structure diameter (d), and theratio of sump depth to shaft diameter (Hs/D) on the energy dissipation efficiency (EDE) was examined. Theeffect of these parameters was evaluated in three stages: first, each parameter was assessed individually, then in pairwise combinations, and finally all three parameters were evaluated together.The results indicate that flow rate had the greatest influence on EDE. The highest efficiency (92.79%) occurred at a flow rate of 10.67 L/s, while the lowest (88.93%) corresponded to 25.22 L/s. Consequently, EDE was found to decrease with increasing flow rate.The simultaneous effect of all three parameters (diameter, flow rate, and sump depth) on energy dissipation efficiency shows that, for a 12 cm diameter and a flow rate of 10.67 L/s, the highest efficiency of 94.59% corresponds to Hs/D=1. For the same diameter and a flow rate of 25.22 L/s, the highest efficiency is 88.92% for Hs/D=1. For a 16 cm diameter and a flow rate of 10.67 L/s, the highest efficiency is 94.08% for Hs/D=1. For this same diameter and a flow rate of 25.22 L/s, the highest efficiency is 90.35% for Hs/D=2.ConclusionsIn the present research, a physical model of a sewer vortex drop shaft with a spiral inlet was investigated in the Hydraulic Structures Laboratory at Shahid Bahonar University of Kerman. This study examined the effect of three parameters including discharge (Q), the diameter of the inlet structure (d) and the ratio of the depth of sump to the drop shaft diameter (HS/D) on energy dissipation efficiency (EDE). Separate analysis of the individual parameters revealed that the influence of flow discharge (Q) on EDE was greater than that of the other two parameters (diameter and sump depth ratio), accounting for 79.92% of the effect. The two-parameter analysis concerning the interaction of diameter and discharge on EDE showed that at a discharge of Q=10.67 L/s, the highest EDE (93.15%) was achieved with a 12 cm diameter. Furthermore, when the discharge increased to Q=25.22 L/s, the maximum EDE (89.25%) was recorded for the 16 cm diameter. Regarding the combined effect of diameter and sump depth ratio on EDE, the results indicated that for a 12 cm diameter, the peak EDE (92.21%) occurred when HS/D=1, meaning the sump depth was equal to the drop shaft diameter.The results of this study confirm that all three parameters—flow discharge, inlet diameter, and sump depth—affect the energy dissipation efficiency (EDE), with flow discharge exerting the greatest influence. Future work should investigate the effect of other geometric parameters of the spiral inlet, particularly the slope of the inlet channel bed and the slope of the inlet structure itself, on the EDE of vortex drop shafts.Keywords: Energy dissipation efficiency, Discharge, Vortex drop structure, Laboratory model, Spiral inlet.AcknowledgmentsThe authors would like to thank all participants of the present study, especially the civil engineering department of the Shahid Bahonar University of Kerman which made this research possible.Conflict of InterestThe authors declared no potential conflicts of interest concerning the research, authorship, and publication of this article.FundingThe authors received no financial support for the research, authorship, and publication of this article .Data Availability StatementsData Availability Statement: All information and results are presented in the text of the article.Authors’ contributionAll authors contributed to the study conception and design. Material preparation, data collection and analysis were performed by all authors. The first draft of the manuscript was written by E. F.K. and all authors commented on previous versions of the manuscript (S. A.Z., E. F.K., and M. Gh.H.). The final revisions have been applied by E. F.K., and M. Gh.H. Moreover, all authors have read and approved the final manuscript.
Original Article
Irrigation network management
Shima Azadeh Ranjbar; Majid Kholghi; Afshin َAshrafzadeh
Abstract
Extended AbstractIntroductionIn countries such as Iran, where drinking water, agriculture, and industry heavily rely on groundwater resources, management and protection are fundamental priorities. Excessive extraction has caused severe decline in groundwater levels and water quality reduction. Given ...
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Extended AbstractIntroductionIn countries such as Iran, where drinking water, agriculture, and industry heavily rely on groundwater resources, management and protection are fundamental priorities. Excessive extraction has caused severe decline in groundwater levels and water quality reduction. Given increasing population and surface water shortage, dependence on quality groundwater has intensified significantly.The Qazvin Plain, as a major agricultural and industrial hub, plays an effective role in regional food security and economic development. Agricultural and industrial activities have imposed increasing pressure on water resources. Although part of water demand is supplied through the Taleghan Dam and seasonal rivers, this plain has severe dependence on groundwater with increasing extraction, leading to level decline and serious quality challenges.The Qazvin Plain is located within 49°10' to 50°40' East longitude and 35°20' to 36°31' North latitude. The plain area is 5059.3 square kilometers with elevation ranging between 1131 and 2902 meters. With semi-arid climate, it receives average annual precipitation of 317 millimeters. With 250,000 hectares of agricultural land, the agricultural sector accounts for more than 85 percent of water consumption. The objective is to classify groundwater quality for agricultural, drinking, and industrial uses, and investigate spatial and temporal variations over a 20-year period from 2001 to 2021.MethodologyGroundwater quality data were obtained from Qazvin Regional Water Company. Water type and facies were determined using the Piper diagram. Qualitative classification for agricultural purposes was conducted according to Wilcox classification, for drinking according to Schoeller classification, and for industrial purposes using Langelier Saturation Index (LSI). The Wilcox method classifies water based on electrical conductivity (EC) and sodium adsorption ratio (SAR) into four classes: excellent, good, average, and unsuitable. Schoeller method classifies water into six classes based on total dissolved solids (TDS) and total hardness (TH). Langelier index categorizes water as corrosive (LSI<0), balanced (LSI=0), or scaling (LSI>0). Spatial and temporal zoning maps were prepared using Kriging interpolation in GIS at five-year intervals.Results and DiscussionPiper diagrams analysis over five periods (2001-2021) revealed continuous aquifer degradation. In 2001, most samples showed calcium-bicarbonate facies indicating fresh water. By 2006, samples shifted toward calcium-sulfate facies. In 2011, degradation accelerated with dramatic dispersion increase and sodium-chloride facies emergence indicating serious salinization. By 2016, critical condition became evident with high facies diversity. In 2021, crisis peaked with maximum dispersion, where calcium-bicarbonate facies appeared only in limited samples, and significant portions showed saline facies dominated by sodium-chloride and sodium-sulfate.For agricultural water quality, no sample was excellent quality. Good quality decreased from 25.25% in 2001 to 17.91% in 2021 (29% reduction). Average quality increased from 46.46% to 58.95%, and unsuitable samples fluctuated between 14.23% and 33.33%. Medium and unsuitable categories comprised 75 to 92 percent.For drinking water quality, about 70% of samples remained in good to average categories, but good quality decreased from 29% to 22%. Completely inappropriate category increased from zero to 2.74%. In total hardness, good quality declined from 39% to 24%, while acceptable water increased to 44%.For industrial water quality, significant changes occurred. Corrosive water decreased from 96.97% to 70.1%, while scaling water increased dramatically from 2.02% to 23.1%. Balanced water comprised only 1 to 6.7%. More than 93% falls into corrosive or scaling categories, requiring treatment before use.Spatial-temporal analysis revealed northern areas had best quality while southern areas faced worst quality, with degradation advancing from south to north. For agriculture, medium and unsuitable water increased from 75% to over 90%. For drinking, good quality decreased from 29-39% to 22-24%. For industry, over 93% are either corrosive or scaling.ConclusionsGroundwater resources show concerning degradation trends. Facies evolution from fresh to saline types, dramatic diversity increase, and significant reduction in suitable quality represent serious warnings.For agriculture, unsuitable water increased from 75% to over 90%, necessitating urgent strategies including extraction control, cropping pattern modification, and drainage systems development. For drinking, good quality decreased from 29-39% to 22-24%, with southern areas requiring advanced treatment. For industry, more than 93% are corrosive or scaling, requiring treatment.The spatial pattern indicates degradation advancing from south to north. The trend shows increasing salinity and hardness resulting from excessive extraction, reduced recharge, and likely saline water intrusion. This requires urgent actions including extraction control, artificial recharge enhancement, agricultural return flows treatment, and pollution prevention. Without fundamental measures, sustainability will be severely threatened.Keywords: Langelier index, Piper, Qazvin aquifer, Quality zoning, Schoeller, Wilcox.AcknowledgmentsThe authors wish to express their sincere gratitude to the Editor and the two anonymous reviewers for their insightful comments and constructive feedback, which significantly improved the quality of this manuscript. We also thank the Regional Water Company of Qazvin for providing the necessary data for this research.Conflict of InterestThe authors declared no potential conflicts of interest concerning the research, authorship, and publication of this article. Confirmation. FundingThe authors received no financial support for the research, authorship, and publication of this article.Data Availability StatementsThe datasets generated and/or analyzed during the current study are available from the corresponding author on reasonable request.Authors’ contributionAll authors contributed equally to the conceptualization of the article and writing of the original and subsequent drafts. Sh. AR. handled the methodology, formal analysis, investigation, data curation, visualization, and initial draft preparation. A.A. and M. Kh. provided supervision and validation for the study. Resources were provided by M. Kh., A. A., and M. Kh. shared responsibility for the final review and editing of the manuscript. All authors have read and agreed to the published version of the manuscript.
