The aim of this study was to investigate factors affecting farmers' participation in PRESSURIZED IRRIGATION projects—a crucial topic in sociology and priority in water sciences. Using an interdisciplinary approach combining sociology and water engineering, data were collected from 6, 073 farmers in Khorram Darreh city through proportional stratified-random sampling, employing questionnaires and interviews. Findings revealed that social cohesion, satisfaction, trust, and awareness, along with land distance from village centers and agricultural land area, exhibited significant positive relationships with participation. Conversely, social attitude, education level, and garden area showed significant negative relationships with participation. Age, water rights, and source water quantity demonstrated no significant effects. Regression analysis indicated five variables—awareness, trust, satisfaction, attitude, and cohesion—collectively explained 30% of participation variance (R² = 0. 30). These results highlight the importance of social indicators for IRRIGATION project success and emphasize the need for policymakers to strengthen social capital within agricultural communities.

In recent years, some researchers say that the development of PRESSURIZED IRRIGATION systems has led to an increase (sprinkler & drip IRRIGATION) in irrigated area resulting increase water consumption from reservoirs and reducing aquifer charging. Because they do not have a positive effect on the water balance of the basin, they are considered as inefficient activities. Critics states IRRIGATION methods do not really save water. They believe that in estimating the efficiency of IRRIGATION, runoff and deep percolation are not part of the losses and can be used in some way. The key point in evaluating the effectiveness of PRESSURIZED IRRIGATION systems should be based on the expected capabilities as well as the scale of their application. Naturally, the performance of the IRRIGATION systems in the agricultural sector with the aim of preventing water losses on a farm scale. Studies show that during the last thirty years, IRRIGATION efficiency in the country has increased from 29. 7% in 1991 to 43. 8% in 2016. The main factors of this increase were the interventions of PRESSURIZED IRRIGATION systems, increasing the level of knowledge of users, expansion of IRRIGATION networks and some other cases. Its main message is to reduce water losses inside the farm and the effectiveness of these systems. Therefore, as expected from PRESSURIZED IRRIGATION systems, reduction of runoff losses and deep percolation and water supply in the root zone of the plant has been successful. Due to the lack of control over water abstraction from reservoirs, its effects on the basin scale and groundwater aquifers may not be tangible. The solution to these cases is related to the executive duties of other water organizations. This report first deals with the quantitative development of PRESSURIZED IRRIGATION systems in the country and also expresses some criticisms regarding their ineffectiveness. Then, according to the studied conditions and scales and expectations from the systems and definitions of some controversial terms, the final analysis is presented based on the effectiveness of PRESSURIZED IRRIGATION systems.

Nowadays, water scarcity has become a concern in Iran, and agriculture in particular appears to be at the core of the water shortage problem. The use of modern IRRIGATION technologies has been proposed as one of several possible solutions. This survey research aimed to analysis adoption behavior of PRESSURIZED IRRIGATION technology by farmers. Statistical population of this research consisted of all the farmers of Dashtestan County (N=20000), Bousher Province. Using Cochran formula, size of the sample was determined (n=243). The respondents were selected by stratified sampling technique. Content validity of the questionnaire as research tool was confirmed by a panel of experts. Calculated Coronbach alpha coefficients (0. 87-0. 97) revealed that the reliability of the questionnaire was suitable. Correlation coefficients revealed positive significant relationship between age, farming experience, numbers of family members which engaged in farming, agricultural loans, loans used for developing PRESSURIZED IRRIGATION, farm investment, investment in water supply, distance to the nearest center of Agricultural Services, number of labor, number of farmland plots, number of neighboring farmers which used PRESSURIZED IRRIGATION, contacts with extension agents and participation in extension courses as independent variables with the adoption of PRESSURIZED IRRIGATION, as dependent variable. The results of path analysis showed that "knowledge" has most impact on adoption of PRESSURIZED IRRIGATION system with total path coefficient 0. 359. Overally, findings of this research indicated that adoption behavior of PRESSURIZED IRRIGATION technology was influenced by a set of variables, including: farming variables, economic variables, technical variables, personal and psychological variables, and support service variables.

The delayed strain property of polyethylene pipes makes their reaction to water hammer different from that of elastic pipes. The present study focuses on the effect of viscoelastic properties on the optimal design of PRESSURIZED IRRIGATION system taking into account the impact of water hammer. For this purpose, the three models, the optimizer, the hydraulic steady solver (HSS), and hydraulic transient solver (HTS) were coded together in the form of a computer model. In the optimizer model, the initial population is created from the available diameters. Then, for each member of this population, in the HSS, the values of pressure in the nodes and velocity in the pipes are calculated. These values are sent to HTS as an initial condition. In the HTS, by applying a water hammer condition on the system, the maximum overpressure in each node is calculated and the results are sent to the optimizer model. Here the value of the objective function is calculated by observing the constraints for each member of the initial population and relative compatibility is obtained for all members. By applying the operation of mutation, intersection, replacement with the elitist approach, the next generation is finally calculated and the mentioned steps are repeated until the condition of stopping the calculations and determining the optimal answer is reached. Validation of the HTS in viscoelastic pipes using data measured at the Imperial College (London, UK) and considering three Kelvin–, Voigt elements and retardation times of 0. 05, 1. 5 and 5 seconds for these three elements are done. The results showed that for wave speed of 390 m / s, the measured pressure fluctuations are in good agreement with the calculations. After confirming the model results, water hammer simulation of Ismailabad network in the current situation, which is composed of GRP and HDPE pipes, was performed with and without considering the viscoelastic properties for polyethylene pipes. The results of this step showed that the overpressure created in the nodes after applying the water hammer in the viscoelastic state is on average 37% of the elastic state and the range of its fluctuations varies between 20 and 72%. Following the optimal design of the network studied in the present study, the results showed that after reaching the optimal answer, the cost of purchasing and implementing network pipes to about $ 745, 590 and the amount of the objective function or the sum of current and fixed annual costs over the life of the project equivalent to $ 212, 760. These values are 9. 57% and 9. 3% less than the current status values, respectively.

As a solution to cope with the occurring drought in most regions of the world and Iran, the PRESSURIZED IRRIGATION systems have been extensively used. Due to feasibility of implementing these IRRIGATION systems, an extensive pressure could be imposed on groundwater resources, which would be a real threat for sustainable groundwater withdrawal, and the goals of real water saving strategies in aquifers of watersheds will not be met. Analysis showed that it is possible to achieve high IRRIGATION efficiency if the PRESSURIZED IRRIGATION systems are correctly and technically designed based on the climate of the region and then installed and performed appropriately. It is realized that sprinkle IRRIGATION systems might not be recommended in the warm and dry climate of Iran, and instead the localized IRRIGATION systems are suggested and favorable over them. Nevertheless, it is necessary to adopt several fundamental management strategies to prevent the occurrence of rebound effect. Some of the main strategies that would potentially prevent rebound effect are including but not limited to restricting the expansion of cultivated areas, considerable increase of water price, volumetric delivery of water to farmers, changing cropping pattern that is combined with deficit IRRIGATION strategies, crop improvement, and importing virtual water.

Considering the limitation of water resources and the need to increase water productivity in the production of agricultural products, the development of new IRRIGATION systems has been one of the most important policies and activities of the agricultural water sector in recent decades. The purpose of this research is to quantitatively investigate the development of PRESSURIZED IRRIGATION development in Iran and compare it with other countries and regions of the world using the PRESSURIZED IRRIGATION development index, and finally the estimation of the optimal and expected level of its development for the country. According to the results, the PDI index until the end of the sixth development program (2020) is 21.4%, which is low compared to other 23 selected countries. Using the multivariable correlation method between the values of the variables affecting water management such as per capita withdrawal, the share of withdrawal from water resources in the agricultural sector, the area of irrigated lands, and the PDI index of 14 selected countries and applying values like for the Iran country, the desired and expected level of PRESSURIZED IRRIGATION in the country was estimated at 49.2%. In other words, in the coming years it is possible to reduce the negative and undesirable effects of the unbalanced development of modern systems on water resources and the environment, and prevent the occurrence of the phenomenon of "rebound effect", in a favorable and potential way, up to half of the irrigated lands in the country should be equipped with PRESSURIZED IRRIGATION systems. Meanwhile, according to the latest statistics, until the beginnings of 2023, the PDI has reached to 30% (2.9 million hectares). Therefore, there is still room for further development in terms of the necessary arrangements and under the condition of creating infrastructures, and necessary control rules and regulations by the related organizations.

Given the diversity of PRESSURIZED IRRIGATION systems, the matter of choosing the appropriate system is one important issue. The appropriate system(s) in each region could be determined considering several factors such as topography, soil characteristics, climate (especially temperature and wind), crop type, quantity and quality of water resource, labor requirement, farmers' skills, economic conditions and social and cultural contexts in the region. The aim of this research was ranking of the PRESSURIZED IRRIGATION systems in the area of 6000 ha located in the Dinawar, Sahneh district in order to select the proper PRESSURIZED IRRIGATION system(s) in the region. Analytical Hierarchy Process (AHP) was used for ranking of the systems. For this purpose, affecting factors on the choice of IRRIGATION system classified to physical and socio-economic categories and for each category related indicators were defined. The score of each criterion for each system was determined in the scale of-3 to +3 based on the analysis of available data and reports in the study area. The overall score for each system was determined by weighted summation of the score of indicators. Only applicable system for areas with slope over 20% is localized IRRIGATION system. The semi-classic and solid set-portable sprinkler IRRIGATION systems are determined as the most appropriate IRRIGATION systems for the area with slope less than 20 percent.

Rejection of PRESSURIZED IRRIGATION by farmers is the problem in the agricultural sector in the north of the Khouzestan province. As the statistics show, only five percent of the farmers used to do this type of IRRIGATION systems. Therefore, in this study by using field study and Logit model, causes of rejecting PRESSURIZED IRRIGATION methods in three townships Shosh. Andymeshk and Dezful have been studied. Farmer's society is divided to two groups: modern IRRIGATION and traditional users. In the first group there is information from 51 users by using census methods and in the second group there are 173 farmers by using stochastic sampling methods in 2009-2010 cultivation seasons. Study results show that small pieces, loan getting method and ownerless land are the most important obstructive factors in use of modern IRRIGATION systems. Having education, land ownership and bigger cultivator are Booster factors of willingness to accept. But age and number of pieces have negative impact on farmer's attitude in use of modern IRRIGATION systems.

Some of common hydraulic methods for designing PRESSURIZED IRRIGATION systems are: (i) unit head loss method, (ii) (maximum allowable) velocity method, and (iii) percent head loss method. In this research, a twostage economic optimization algorithm was introduced to design PRESSURIZED IRRIGATION systems and was developed in LINGO programming environment. Results obtained by this model were compared with the ones from the foregoing hydraulic methods for a hypothetical sprinkle IRRIGATION system comprised of 3 manifolds to assess the performance of the new algorithm. The results showed that this optimization algorithm resulted in 3% lower costs for a small IRRIGATION system and favorable distribution uniformity. Also it was concluded that system design according to unit head loss method with maximum 0.01 m.m-1 head loss resulted in the highest distribution uniformity in comparison to the other methods and the optimization algorithm, unit head loss method with maximum 0.02 m.m-1 head loss and maximum allowable velocity method followed it. The standard deviation of the sprinklers outflow values as compared to the namely outflow value were estimated 0.1, 0.03, 0.05 and 0.12 lit.s-1 for the optimization method, unit head loss method with maximum 0.01 m.m-1 head loss, unit head loss method with maximum 0.02 m.m-1 head loss, maximum allowable velocity method, respectively.

In the first and second national development programs signification attention has been focused on the efficiency of water use. The use of PRESSURIZED IRRIGATION system received priority in the agricultural strategy set by the government. However, the development of these systems has faced many problems and uncertainties. Recognizing these problems and unknows will be a helpful guide for agricultural policy makers and will assist them in their practical approach to the problem. Linear programming was used in order to analyze these systems to assess their optimum water allocation and efficeincy. The results of this study showed that in case these systems are disigned and operated properly they can optimize water use by increasing effiency, reducing evaporation, and providing a more suitable cropping pattern.