نشریه آب و توسعه پایدار
سال هشتم شماره 4 (پیاپی 22، زمستان 1400)

In recent years, development strategies have changed from emphasizing the central role of the government to improving the participation of NGOs and non-governmental organizations. The present study aimed to survey effective factors on participation for management of the Ghale-Chay irrigation and drainage network in Ajabshir county of East Azerbaijan province. The research type was descriptive-correlational. The statistical population included 894 farmers. The sample size (n=201) was determined using a systematic random sampling method. Based on the experimental model and using SPSS26 software data analysis was performed. Data were collected using a questionnaire designed by the researcher. The results of multiple regression showed that in total 0.508% of the variance changes of the dependent variable "participation in irrigation network management" are explained. According to the rate of β statistics; the variables of education with -0.406 have the highest and the appropriate function variable with access to farms with the value of 0.197 have the least effect on participation in irrigation network management. It can be concluded about education that the current situation in network management does not meet the expectations of educated people. Therefore, regarding the proper function of access roads to farms, because the agricultural type of the region tends mainly towards the traditional, the effect of this variable from farmers' point of view is not significant

In recent years, many cities have been suffering from a shortage of drinking water, mainly due to population growth. Therefore, the tendency to curb excessive water consumption by identifying the main factors affecting consumer behavior in the management of drinking water resources has become very important. Understanding this necessity, the purpose of this study is to identify, and prioritize the factors affecting the pattern of water consumption in the home sector. In this regard, by reviewing the literature in the field of water and interviewing industry experts, the factors affecting consumption in various criteria were identified and monitored. Then, through fuzzy Delphi, action factors were examined and finally, 7 main economic, social, cultural, technical and engineering, legal and managerial, spatial and temporal criteria with 26 sub-criteria were identified. Evaluation and ranking of these factors were performed using the fuzzy Topsis technique. Results obtained from the research of family awareness with weight (0.756) first rank, use of water reducing devices (0.670) second rank, advertising and education (0.603) third rank, consumption motivation (0.545) rank Fourth, water tariffs and pricing (0.508) were ranked fifth and the use of new valves (0.423) was ranked sixth. The findings show that among the various factors, educating and increasing the awareness of households on how to consume water and the use of reducing devices can play an important role in managing water consumption.

The utilization of new irrigation technologies is a solution that serves farmers to manage production risk (yield) through the optimal storage and allocation of resources. This study was conducted to predict the factors affecting the adoption of new irrigation technologies among farmers in the Sistan region using the logit model. Sampling in this study was a random cluster method in which 100 farmers were selected from the villages in which the pressurized irrigation project was implemented. The required data were collected using a questionnaire from farmers in the crop year 2019-2020 and were analyzed by SPSS24 software using the logit model. The results of logit regression showed that age, education, ownership, the area under cultivation, and income explain between 71 to 94.6% of the changes in the adoption and non- adoption of pressurized irrigation and social and economic factors have been able to change between 69% to 92% of changes in technology acceptance. only economic factors such as low-interest rates on bank facilities, sufficient amount of bank facilities, farmer investment capacity, etc. had a significant effect (P ≤ 0.05) on the adoption of pressurized irrigation technology by farmers. Therefore, appropriate mechanisms should be provided to eliminate these restrictions according to the conditions of farmers and use scientific and practical training to encourage farmers to accept this technology, on the other hand, due to the hot and dry climate of the region should be suitable crops and gardens with this method, pressurized and environmentally friendly irrigation methods that are more economically efficient and effective, should be introduced to farmers.

Identifying the effective and determining factors of water scarcity in each region is a necessary condition for proper management of water supply and demand and laying the groundwork for adaptation to water scarcity. Although Kermanshah province is not in a crisis situation according to the usual indicators for determining the water crisis, the continuation of the current situation will lead to a crisis and requires a review of the province's water resources management approaches. This research seeks to identify and prioritize the determinants of water scarcity in Kermanshah province in the theoretical framework of institutionalism and with the hierarchical analysis process. For this purpose, with the Delphi method and hierarchical analysis tool, and EXPERT CHOICE software, these factors were identified and prioritized. The results show that contrary to conventional approaches to water resources management, which emphasizes water supply management, the role of demand-side factors in the problem of water shortage in Kermanshah province is much more decisive so that 72.5% of the water shortage problem is explained by these factors.  Demand-side factors, respectively, priority and share in water scarcity are: low water productivity in the agricultural sector (0.42), uncontrolled extraction of underground resources (0.21), agricultural production structure (0.13), virtual water exports (0.10), water loss in the route (0.06), water consumption culture (0.05), lack of meter (0.03). On the supply-side, the amount of precipitation (0.38), water budget (0.18), evaporation (0.18), time mismatch between precipitation and consumption (0.13), type of precipitation (0.05), precipitation fluctuation (0.05), and insufficient utilization of gray water (0.03) have the most important role in creating stress, respectively.

Farmers, who are faced with the problem of irrigation water salinity, sometimes ask questions about the yield forecast under the effect of irrigation water salinity (ECiw) and the volume of applied water (Viw). The answer to this question requires knowledge of the crop production function. The aim of this study was to investigate the interaction between ECiw and Viw on wheat grain yield (Narin cultivar) in the Yazd region. For this purpose, the response of wheat yield under the effects of irrigation water salinity (including 3, 5, and 8 dS.m-1) and volume of applied water (from 4500 to 11600 m3.ha-1) was analyzed during 2017-2018, 2018-2019, and 2019-2020 cropping seasons. The results showed that the effectiveness of applied water on wheat yield has increased in saline conditions than in non-saline conditions. Therefore, wheat growers in saline areas should be confident about the adequacy of available water to meet the field water requirements (both ET and leaching requirements) and also follow the irrigation scheduling more carefully and obsessively compared to none-saline conditions. In this case study, a wheat yield function was presented and evaluated, as well. This function works based on the salinity and the volume of irrigation water (ECiw and Viw). With a coefficient of determination (R2) of 0.67, this function is expected to estimate the wheat yield with an approximate error of ±524 kg.ha-1. This equation can be used to estimate the production decline due to increasing salinity of irrigation water or decreasing the volume of applied water, to predict the yield before the harvest time as well as to meet the field water required to produce a certain amount of grains in the studied region

Due to water shortage in the country, improving the irrigation management of potato fields can reduce water consumption and increase the efficiency of this important product. For this purpose, it is necessary to have sufficient and accurate information about the status of applied water and water efficiency in the conditions of farmers' management. Therefore, the amount of applied water, yield, and water efficiency in the conditions of farmers' management in two major potato production areas in Razavi Khorasan province were investigated. The two areas of Fariman and Torbat Heydariyeh with the highest area of cultivation and production of potatoes were selected as pilots cities. The method of irrigation in all fields was the drip method. In experimental farms, irrigation and agronomic characteristics, water source and irrigation network characteristics, required meteorological data, applied water volume, potato yield, and water efficiency in the crop year 2019 were measured. Also, the volume of water used by farmers was compared with the estimated irrigation needs based on meteorological data from 2019 and the last ten years calculated by the Penman-Monteith method. The amount of applied water based on meteorological data in 2019 was about 26% and to 10-year statistics was about 15% more. The results also showed that the volume of applied potato water in the studied farms varied from 9888 to 14573 m3/ha and its average was 11885 m3/ha. Potato yield in selected fields varied from 28600 to 60000 kg/ha and the average was 40399 kg/ha. Water efficiency varied from 2.22 to 5.25 and the average was 3.42 kg/m3

In most practical hydraulic engineering problems, accurate flow measurements are required. Understanding flow quantities is an important point in water resources management. Therefore, providing the most appropriate velocity distribution estimation relation that is consistent with the measurement data has always been of interest to researchers. With the development of entropy theory, these methods have been used in a wide range of engineering sciences, including hydraulics and fluid mechanics. In the present study, using the Renyi entropy method, the effective parameter "m" on the Renyi entropy parameter "G" was investigated and the velocity distribution in a circular pipe in the conditions that 36.2, 50, and 70% of the circular pipe fills. It was estimated at two points by measuring the velocity at depths (0.1D-0.9D), (0.2D-0.8D), and (0.3D-0.7D) relative to the water level. In order to determine the accuracy of estimating the velocity distribution using the Renyi method, the correlation coefficient and the root mean square error was used and also to determine the accuracy of entropy parameters, normalized root mean square error was used. The results showed that the Renyi entropy method has high accuracy with observational data. Also, velocity measurement at depth (0.9D-0.1D) from the water surface for 36.2, 50, and 70% of the circular pipe, with the normalized root mean square error to 0.2325, 2.36, and 0.51 respectively, has higher accuracy.

Internal erosion and piping pose major hazards to earth dams. Experimental method of filter performance evaluation and design method based on criteria with simple parameters are the two main groups of filter selection and design in earth dams. Determining the appropriate gradation for the filter of earth dams, despite the apparent simplicity of experimental criteria, has posed important technical and economic issues for engineers in large numbers of large projects. This problem has become larger in situations where the clay soil is dispersive or suspected of dispersivity because on the one hand, estimating the true potential of dispersivity is not easy due to the multiplicity of detection tests, and on the other hand, the application of few criteria in filter design prevents erosion of available dispersive soils, usually leading to the selection of very fine and costly gradation. With this approach, a no erosion filter test device was made to perform laboratory tests and study the accuracy of the design methods. As a case study, by performing basic dispersivity experiments on the clay core samples of Bar Neishabour and Bidvaz Esfarayen dams, the degree of dispersivity potential in these soils was determined. By performing a number of No Erosion Filter tests, the best grain size of the filter, which prevents the erosion of the soil of Neishabour Bar Dam at different pressures, was obtained with an accuracy of 0.1 mm which is different from the filter executed in the dam. Also by testing the design criteria and the laboratory method of filter design for the core soil of Bidvaz Esfarayen dam, it was found that there is a big difference in the results of each design method.

Arsenic is a carcinogenic contaminant, and arsenic-contaminated drinking water is the major source of exposure to this hazardous metal. In recent years, the city of Sirjan has faced the problem of water sources pollution to arsenic and due to the existence of conventional water treatment plants in this city, the results of this study can be an important step to reduce and even eliminate this problem. In this study, the response surface methodology used to investigate the effect of pH (7,8,9), turbidity (<1,5,10,15,20 NTU), initial arsenic concentration (50,100,150,200,250 µg/l) and coagulant dose (5,10,15,20,25,30 mg/l) on the residual arsenic concentration after coagulation and flocculation process using ferric chloride. Synthesis of the tested samples was performed using the effluent of the treatment plant. Based on the results, the variables under study follow a quadratic model. The predicted quadratic model for the behavior of the parameters fits the results well. Investigation of the interaction effects of variables showed that the concentration of residual arsenic is greatly affected by pH so that by increasing it in the study area, the concentration of arsenic output also increases. This negative effect of increasing pH can be partially compensated by increasing turbidity. According to the coefficients of factors in this model, linear and square effects of pH, the interaction of pH and turbidity, and the linear effect of coagulant dose had the greatest effect on residual arsenic concentration. Taking into consideration of operation conditions, at pH=8, turbidity=5 NTU, using 20mg/l coagulant, reduced arsenic concentration from 150 µg/l to 3.84 µg/l

This study was conducted with the aim of the Analysis of the challenges of applying sustainable environmental operations. The statistical population of the study was all households of wheat farmers in Khorramabad County (N = 12500). The sample size was determined using Cochran's sampling formula of 240 heads of farmers' households. The data collection tool was a questionnaire whose validity was determined by a panel of experts including faculty members of the Department of Agricultural Extension and Education, Agricultural Sciences, and Natural Resources University of Khuzestan, and its reliability for communication channels and water protection behavior were confirmed using Cronbach's alpha coefficient and combined reliability method, respectively.  Data analysis was performed in two sections of descriptive and inferential statistics by SPSS and Lisrel8.54 software. The results of this prioritization of the challenges of implementing sustainable environmental operations based on farmers' perspectives showed that the most important challenges in this sector included "inappropriate organizational structure for effective policy making" and "lack of extension and training courses". In addition, the results of factor analysis classified the known challenges into three factors: educational and professional challenges, policy and institutional challenges, and economic and supportive challenges, of which 42.69% explained the variance of all factors

Today, watersheds are severely affected by natural and man-made stresses, and their ability to recover and adapt to altered conditions depends on the resilience of watersheds. Therefore, due to the importance of this issue and the necessity to explain  management models in  order to promote resilience in the country's watersheds, the present paper aims to analyze the concept, application, and methods of hydrological resilience assessment as one of the resilience dimensions in comprehensive watershed management. Studies in this field are very limited worldwide but have an upward trend. Accordingly, the methods used to evaluate hydrological resilience have so far been limited to the use of simple compilation methods such as determining the arithmetic mean of some important hydrological indicators, using the Budyko curve and the Convex model. Budyko's curve analysis was mostly based on rainfall, evapotranspiration, and runoff production. But the convex model is used by considering the failure thresholds of hydrological indicators and establishing a relation between the process of long-term changes and the failure thresholds of indicators. The indicators used are multitude and have different applications depending on the hydrological conditions of each watershed. Among the most important of them can be the ratio of drought index to runoff, temporal trend and frequency of low and high water flow, change in annual water yield, groundwater level, surface runoff intensity, river enrichment from nutrients, and heavy metals, forest degradation percentage, soil erosion, sediment yield, and saline water levels are all the result of the interaction of other influential environmental factors, such as climatic, ecological, economic, biophysical and social.

One of the main problems in urban development is the increase of impenetrable levels, which leads to an increase in runoff and the occurrence of urban floods. In this study, the current situation of floods in the eighth district of Herat city was investigated using the EPA-SWMM mathematical model  in terms of flooding. Then, six different modes were modeled separately and simultaneously in the form of two methods low-impact development of rainwater storage barrels (in two different sizes) and biological biomass units. The results of this study showed that by using low-impact development methods, the negative effects of floods with a return period of 10 years can be reduced by at least 40%. After that, simulation has been done using the flood mitigation reservoir method. The results showed that the construction of delayed reservoirs causes a delay in the peak discharge time and reduces the peak flood discharge. Also, the use of flood mitigation reservoir and unit biomass method and rain barrel method with larger diameter reduces flooding by 80% and the use of unit biomass method and the smaller diameter barrel method reduces the volume of urban floods by 75%.