نشریه پژوهش های نوین در مهندسی آب پایدار
پیاپی 1 (بهار و تابستان 1401)

Population growth around the world and rising water demand in most parts of the world have caused many problems in distributing and allocating water resources in different sectors of drinking, industry and agriculture. Ardebil Plain has a shortage of water due to its cold and dry climate in providing water consumption of agriculture. One of the ways that can some extent solve this problem is comprehensive water management, which is an important economic method and values ​​can be balanced between supply and water demand. In this study, the production function was used to determine the economic value of water in the production of potato and alfalfa products. The results showed that the average final production of irrigation water input for potato and alfalfa product was 0.459 and 0.25, with economic value of 11486.86 and 2759.4 Rials per cubic meter respectively. Also, the highest amount of water consumption in potato and alfalfa production was obtained by 14400 cubic meters and 10,000 cubic meters, respectively, and average water consumption, respectively, was 12.03 and 6786.52 cubic meters, respectively. As a result, by informing farmers about the consequences of unnecessary harvesting of water resources and reforming agricultural water prices based on the ultimate value of production, the loss and unnecessary consumption of water in the agricultural sector can be prevented.

Water plays an important role in changing the policies and economy of the 21st century. One of the causes of tensions and conflicts in West Asia is expected to be related to the water shortage crisis; But water shortages alone do not cause these tensions; because the wrong policies and governance also cause these conflicts. Fair use of common water resources is one of the priorities of stakeholders, which with a fair attitude will reduce conflicts and increase their cooperation and participation. This paper examines international law, the structure of negotiations, discourses, and types of diplomacy to resolve tensions over water issues. It also provides an overview of the challenges posed by the water crisis. The results of these studies indicate that despite the existing laws on transboundary water resources, the lack of a universally agreed definition of "international water law" is still one of the reasons for the failure of negotiations and water treaties. Also, some ambiguities in the article of international water laws are other problems in resolving water disputes. In this regard, the guidelines for implementing innovative water diplomacy in each region may be a good solution for the sustainable management of transboundary water resources. In this way, the current water crisis can be managed through appropriate management structures in the joint use of available resources and the implementation of macro-planning based on international interactions and using all capacities. This management requires the creation of an integrated database and accurate knowledge of resources.

Considering the effect of wind speed on important climatic issues such as evaporation, wind speed was investigated in seven meteorological stations of Zayandehrud basin using time series method.  In this study the periods includes 7 days, 15 days, 30 days, seasonal and daily. Outlier data were determined by box diagram, normal and Grubs beck methods. The modeling was performed by examining the autocorrelation and partial autocorrelation diagrams using the criteria of Akaike, Schwartz and Hannan Quinn. Kolmogorov-Smirnov and Jark Bera tests that were used to check the normality of data and Durbin Watson and Pert Manto tests were used to check the accuracy of the model. Trend and homogeneity tests were performed using Matlab and modeling was performed using Minitab, Eviews. For validation at daily and 7-day intervals, 5% of data were considered, at 15 days and 30 days, 10% of data and at seasonal intervals, 20% of data. The trend analysis was performed by non-parametric Man Kendall method and the trend was observed in the majority of intervals. also, based on the results obtained (the coefficient of determination above 0.7 and the mean square error and error percentage below 20%) the model of SARIMA was introduced as the best model in the 7-day, 15-day and 30-day time intervals, and ARIMA model in daily and seasonal  intervals

With the increase in population, global warming and climate changes, in the not too distant future, especially in arid and semi-arid regions of the world, there will be a problem of water shortage, which can cause severe crises in various fields. Therefore, it is necessary to study the behavior of water in the past and provide solutions in order to achieve sustainability, to a large extent prevent the occurrence of problems caused by water scarcity such as desertification, development of poverty, threats to food security, air pollution and other destructive environmental, social and economic effects. . In a world with water security, the importance of the real value of water and the importance of water consumption for human life and well-being become one. In a world with water security, the productive power of water is under control and its destructive force is minimized. Water security also means managing and dealing with environmental protection and the negative effects of poor management. In water security, ending the scattered responsibility of water and integrating the management of water resources in all sectors including finance, planning, agriculture, energy, tourism, industry, education and health are considered. In this research, examining the trends of water consumption and scarcity on a regional and global scale, and classifying water scarcity for different years in order to direct and regulate management work in order to achieve the goals of sustainable development, trajectory archetypes have been discussed which can be useful in identifying suitable possible solutions to deal with water shortage, as well as evaluating solutions to reduce consumption, according to the climate of the region and its conditions.

Considering the decrease in rainfall and the quantitative and qualitative limitation of water resources in the Semnan Plain, and considering the drought and water shortage conditions, it is important to study and provide a solution for the optimal use of the potential and existing resources in creating sustainable agriculture. Therefore, it is necessary to choose the appropriate cultivation pattern and avoid the cultivation of crops with high water consumption. For this purpose, by compiling and completing a number of 10 questionnaires at the level of 500 hectares, in the crop year 96-97 among the farmers of the region and using the instructions for determining the water productivity in the fields of the Agricultural Research, Education and Promotion Organization of the Ministry of Jihad Agriculture regarding the determination of water productivity Two strategic crops were applied in Semnan plain, the results showed that the fodder corn plant with a physical productivity index of 5.87 kg/m3 and an economic productivity index of 11516 rials/m3 compared to the wheat plant with a yield index The physical fertility of 0.78 kg/m3 and the economic productivity index of 6055 Rials/m3 can be considered as a suitable cultivation pattern in the Semnan Plain region to increase water productivity.

Water supply networks as a hydraulic system of water transmission and distribution have always been of interest to researchers. The main cause of water transfer in water distribution networks is the pressure head difference between the two points and in case of increasing the standard pressure, the undesirable phenomenon of leakage occurs. Leakage in the irrigation system is economically, socially and environmentally significant. Therefore, leak detection as one of the duties of water and sewage companies in the country has always been a concern. Objectives of the present research includes the detection of water loss points in the water distribution network using the EPANET model and the neurofuzzy method, and compares the two methods and provides a better method for detecting water loss points. In this study, in order to detect leakage in the water distribution network of Mohyabad city of Kerman province, a method based on hydraulic modeling and inverse solution of flow equations to predict the location and amount of leakage in the distribution network Water was introduced using EPANET software and neurofuzzy method with measured values of pressure in a number of network nodes. The results indicate that in the best selected architecture among all tested networks, leakage coefficients resulting from neurofuzzy prediction compared to EPANET modeled values are the most suitable option for modeling and have a coefficient. The correlation between 0.984 and the mean MSE forecast error, equal to zero with the root mean square error (RMSE), 0.0024 (l/s) indicates the optimal forecast accuracy and high reliability of the trained network. The proposed method with a minimum of hydraulic information from pressures, has a good ability to predict the location of leaks in the network and also the use of neurophase method is simple and low cost, in addition, has good accuracy.