نشریه مهندسی آب
سال هشتم شماره 1 (بهار 1399)

Surface water is one of the main sources of agricultural water supply. Therefore, understanding and understanding of the water quality of rivers and their zoning based on the quantity of different elements will help us to make management decisions and reduce water pollution. The purpose of this research is qualitative zoning of Karun River in Khuzestan province in Masjed Soleiman to Ahvaz using fuzzy logic and hierarchical analysis (FAHP). For this purpose, qualitative parameters including: chloride (CL), sodium sorption ratio (SAR), electrical conductivity (EC), sodium (Na), and total dissolved solids (TDS) were used in November 1977. Qualitative parameters were first zoned using IDW interpolation method. Then, each of the obtained maps were fuzzy incremental linear membership function. Then, by preparing a questionnaire, paired comparisons between parameters based on the role of these parameters in determining water quality for agricultural consumption and based on AHP method, weight coefficients of each parameter were obtained. Came. Multiplying the weighting coefficients in the fuzzy layers and combining them, obtained a zoning map for agricultural use. The results show that the Gotvand, Arab Asad, Shahid Abbaspour and Gargar Shushtar stations are very suitable for agricultural use. Ahwaz and Malasani stations were located in a suitable area for agricultural use and Valiabad and Tang Dolab stations were located in a very unsuitable location for agricultural use.

Karun River is the most watery and longest river in the country, which has a strategic position in the western and southwestern regions of Iran due to the existence of numerous industrial centers and agricultural lands and large cities on its shores, and optimal monitoring of water quality is a national necessity. For this purpose, in the present study, the quality of this river was investigated using chemical parameters, TDS TH, So4, CL, Ca, HCO3 Na, and Mg in nine quality measuring stations of water quality changes in Karun river in the period 12/13/2017 to 06/06/2017. . Then, by IDW method, the chemical zoning of water chemical parameters was determined and according to water quality control indicators such as Schuler index, the quality of each of them was determined for drinking consumption. According to Schuler diagram divisions, the quality of Shahid Abbaspour Dam station has changed from acceptable to excellent during this period. Tang Dolab has turned from a completely unsuitable range into non-drinkable. In fact, the decrease in the amount of water in September has caused an increase in solutes in Tang Dolab and Vali Abad stations.

Since water and wastewater companies are one of the significant energy consumers in urban industries, there is a substantial share to increase electricity demand and as a result, increasing the power plants load. The purpose of this study is to present a new evaluation approach for using solar energy in the water and wastewater industry. Therefore, while consideration of the energy consumption in the six regions of Tehran Water and Wastewater Company, requirements for the installation and operation of photovoltaic systems in this company has been investigated. In the present study, the objective functions are energy consumption costs and greenhouse gas emissions; Also, solar energy potential, increasing population rate and water consumption are the most important independent variables and forecasted electricity consumption, carbon tax, and electricity sales price are also dependent variables. The results of this study, which can be based on using the regression model, show that the increase in electricity consumption and costs are 1.5 and 3 times in this period, respectively. To calculate the amount of greenhouse gas emissions, the three scenarios are implemented and compared with the replacement of 5, 20, and 30% of the company required electricity by photovoltaic systems. The reduction in CO2 emissions due to the production of 30% of electricity consumption with solar energy, amounted to 26,712 thousand tons. On the other hand, taxing more than $ 10 per ton of CO2 emissions changes the consumption pattern and reduces the cost of electricity consumption in this industry by $ 5,987,086.

Morning glory spillway, is one of the spillways and used when it is not possible to use any other spillways. With the onset of Submergence and flow Loss, and circulation flows intensify, Spillway performance decrease severely and the height of water in the reservoir increases and Risk of dam damage, caused by the lack of spillway ability of great flow discharge, rises. The increase of the Submergence threshold provide ability of greater flow discharging, without Spillway submergence and its negative consequences. Anti-vortex piers, in addition to correcting circulation and vortexes, may also be effective in increasing the Submergence threshold. To investigate the effect of Anti-vortex piers on submergence threshold, 199 experiments were performed with the physical model on spillways with square and circular inlet section in different modes of number and angle of anti-vortex piers. Results show that in the square spillway, increasing the number (Best mode, 8 piers) or decreasing the angle of Anti-vortex piers (Best mode, 30o), increase the Submergence. In the circular spillway, increasing the number (Best mode, 8 piers) or the angle of Anti-vortex piers (Best mode, 90o), increase the Submergence. At all modes of numbers and angles of piers increasing of submergence threshold in the circular spillway is more than square spillway, But submergence threshold values at all modes in the square spillway is greather. Also, in both spillways the angle of piers more than the number of them affect the submergence threshold.

When water enters the tondab, it goes fast and has a high speed at the bottom of the tandab. So that the current becomes supercritical and has destructive kinetic energy. Therefore, in order to maintain the natural effects downstream of overflows, including rivers and dams, this energy must be consumed. To achieve this, researchers have sought to create energy dissipators. Among them are relaxation pools. The mechanism of relaxation pool is such that it creates a hydraulic jump in a short distance and then from contact with existing accessories such as calming blocks, just walls, perforated walls to wear out. The energy from the tornado and then the hydraulic jump will help. Many people have tried to use perforated and continuous walls individually or in pairs with different flow conditions and geometric dimensions. Therefore, we decided to control the hydraulic jump by examining the simultaneous use of a pair of perforated and continuous walls with the aim of 1- reducing the secondary depth 2- relative energy loss. For this purpose, by software modeling, a continuous wall with dimensions of 80*13*1 cm and a perforated wall with dimensions of 80*7*1 cm with an optimal distance in FLOW 3D software have been investigated. The result was that using a perforated wall and a continuous wall wasted more energy than other scenarios.

Withdrawal of water from subsurface and surface sources There are always problems when using the water transfer method and hydraulic and hydrological rules, the most important of which is closing the mouth of your catchment and catchment channel. One of the methods of controlling sediment entering the lateral catchment is the use of submerged plates. Submerged plates are small pieces of different genders that are placed at a low angle to the flow (10 to 30 degrees), which creates a vortex flow perpendicular to The direction of flow in the bed layers compresses the water and causes the plate and tea to fall down in the bed sediment. It is created to create a channel for the passage of sediments downstream. In addition to reducing their performance, scouring around the plates changes the hydraulic conditions and more sediment enters the reservoir. Examining its amount in selecting the optimal shape increases both the life and efficiency of the plate and more sediment control. Numerical construction with CCHE 2D software for 5 geometric shapes of submerged plates in four landing numbers 0.45, 0.55, 0.6 and 0.66 based on the laboratory work of Davoodi et al. (2015) is simulated with the difference that in addition Rectangular shape 4 Modified shapes are also examined that the purpose of measuring the amount of scour around these plates in order to identify the effect of modifying the geometric structure in reducing scour that plates B3 and then B4 had the best performance.

This research investigates changes in the length of the apron on the scour depth of Culvert downstream. So the experiments were conducted on the apron with different lengths. Results of the study revealed that the depth of scouring has reduced in particle Froude 2 to 22%, 33%, and 66%; and apron in particle Froude 2.5 to 15%, 20%, and 40%; and in particle Froude 3 to 20%, 25%, and 31%, respectively. It shows that length changes and characteristics of apron have positive effects on the scour depth of Culvert downstream.