reza lalehzari

The main problem of water resources planning is the inappropriate allocation between different consumers. Water allocation planning is a complex, multi-variable, and multi-constraint problem, which requires advanced optimization methods to be solved. Classical optimization methods are facing some limitations such as being trapped in local optimum points, and difficulties in handling different variables. In this paper two of these methods including particle swarm optimization, PSO and multiobjective non-dominated sorting genetic algorithms, NGGAII were explored and their efficiency in optimization water reservoir operation problems is compared. Dealing with the necessary of multiobjective programing accuracy, two single objective models was developed separately using PSO to verify the NSGAII results.

Estimating the parameters of infiltration equation and Manning’s roughness coefficient are essential for the optimal design and evaluation of surface irrigation systems. The present study was carried out to calibrate these coefficients for a closed-end border irrigation system with four series of field information. In this regard, the hydraulic surface water flow is simulated using zero-inertia model by WinSRFR simulation model that linked to the particle swarm optimization algorithm for repetitive calculations. The objective function of the optimization problem was the minimization of the difference between the calculated and measured times of advance and recession phases, and four coefficients of the modified Kostiakov equation and Manning’s roughness coefficient were considered as decision variables. The sensitivity analysis of the developed model showed that the coefficient b of infiltration equation in the recession phase and the Manning’s roughness coefficient in the advance phase have the most errors in the predicted results. The results showed that based on the optimized parameters in the model, the values of root mean square error, RMSE, were obtained between 3.77 to 12.86 minutes and the coefficients of residual mass were varied between -0.099 and 0.003 to predict the advance and recession times in the four experimental irrigations. Based on results, with optimization of WinSRFR model, there is accessibility to achieve in application efficiency and distribution uniformity about 86 and 84 percent, respectively (with adequacy about 100 percent) by flow variable (inflow rate and cutoff time).

The main problem in surface irrigation systems is the low irrigation efficiency due to poor management, inaccurate estimation of design parameters and inadequate design. Losses in surface irrigation include deep infiltration and runoff, which is one of the ways to increase the efficiency of border irrigation, using closed-end mode in irrigation systems. This research was conducted to evaluate the effects of geometrical variables (slope and length of border) and flow control (inlet flow rate and cut-off time) on application efficiency and uniformity of water distribution in closed-end border irrigation system. The length, slope, inflow rate, and cut-off time are considered as the decision-making variables for developing the multi-objective genetic algorithm based on the non-dominated sorting. For this purpose, three irrigation borders with closed-end system were considered in the Ramshir network. The optimization algorithm for calculating the objective functions involves maximizing the minimum water depth and minimizing the infiltration depth in a modeling loop. The optimization algorithm was linked to WinSRFR 4.1.3 software to calculate the objective functions. The results showed that the best combination of inflow rate and the cut-off time for 75 mm of required water depth was 1.9 lit/s/m and 150 min, respectively, which increased application efficiency and distribution uniformity to 79 and 78 percent. Furthermore, the application efficiency in the closed-end border irrigation system is higher (30% to 50%) than the open end method in different scenarios.

Groundwater resources, as one of the most important factors in sustainable development, need to be intensely considered. Numerical models such as Modflow and MT3D is an applied tool for simulation and management of groundwater flow and solute transport. In this study, Shahrekord aquifer modeling is provided by the use of monthly data’s including hydraulic heads, depletion volume of the wells, springs and qanats, precipitation values. This model has been developed based on the assessment of the hydraulic conductivity and specific yield coefficients in the calibration process. The study year was divided to 12 monthly stress period for calibration (10 periods) and verification (2 periods). The results showed that the hydraulic conductivity from 6 to 16 m/day and specific yield from 0.03 to 0.07 were varied. The predicted water table in calibration process in comparison to observed values of water levels on piezometers with variance of 0.63. These results confirm the need model of groundwater flow prediction. Moreover, Effective molecular diffusion coefficient, longitudinal dispersity and distribution coefficient were calibrated to achieve acceptable variance between observed and calculated nitrate concentration. The most contaminant particles are in the south zone of aquifer where is the nearby urban wastewater wells. Moreover, the central and south parts of plain have the suitable situations for groundwater discharge because of the high amount of transmissivity.

The price of water in agriculture plays an important role in the water allocation management. Therefore, the optimum strategies of cropping pattern could be designed when water price analysis are considered in a predetermined economic framework. In the present study, a programming model was developed using the genetic algorithm for optimal water allocation in the eastern north of Khuzestan province that is suffering from water deficit. Maximization of benefit per cost ratio was defined as the objective function by a linear equation and the feasible domain of the problem was limited to water resources, cultivated lands, irrigation systems, and economic parameter constraints. In the developed optimization scheduling, there is the set of solutions with the great potential to maximize the net income of cropping pattern in the water shortage condition. Three scenarios of water price including 0, 200, and 500 Rials/m3 have been considered to compare the allocated water, water use efficiency, and net benefit per drop indices for each crop. The results show that by imposing deficit irrigation and an increase in costs, the volume of allocated water together with the efficiency of water usage for tomatoes is increased by 7% and 0.07 Kg/m3, respectively. Furthermore, the same conditions lead to an increase in the cultivated area of wheat and maize. Analysis of evaluation indices indicated that by increasing the price of water, the model decreased the allocated water in vegetables and increased the water usage efficiency and benefit per cost ratio in beans.

Water resource management is a main driver to increase economic productivity for an agricultural area. Under water shortage condition, efficient use of available water is necessary for required sustainable crop production in arid and semi-arid area. Therefore, a combination procedure of mathematical modeling and optimization techniques has been developed for water allocation to maximize the economical productivity and total efficiency of an irrigation scheme.Optimization model is presented using multiobjective genetic algorithm and evaluate by two objective functions. Water use efficiency, cropping pattern, reduction of irrigation losses, effective use of rainfall and cultivated area are considered in the objective functions of the model. Irrigation water requirement for each growing stage and cultivated area have been considered as decision making variables. For field study, the main crops of Baghmalek plain and their related area, the cost of agricultural inputs and final price of crops were collected in farming year 2013-2014. The results show that the optimal cultivation area allocated among various crops is decreased for maize, melon, tomato and onion in drought condition. Tomato, bean and onion have obtained more volume of total available water, respectively. Tomato in relative yield and net benefit ratio, vegetable in the percentage of allocated water and bean in effective use of water have the minimum values of evaluation parameters.

The procedure that is to be selected for a sustainable maintenance of open channels in agriculture largely depends on the type of supervising process and the availability of its appropriate device. In this paper, social acceptance and technical problems related to the contractor, farmer, taskmaster and supervisor were taken into consideration. The study was carried out in conveyance channels of agricultural regions in Lorestan province (Delfan Palin), which is 19 km long, from 2007 to 2010. The layouts of structures were performed with 6 to 8 cm thickness and trapezoidal section by gravel, sand and concrete mix. The main problem and influencing factor for desirable utilization are the wrong change in predetermined section scheme and technical failure to perform, respectively. After the classification and assessment of the problems, some solutions which have more positive effects on the next stages of channel construction were suggested.

Evaluation procedures have been developed for effective design and management of irrigation systems. Furrow irrigation is one of the main types of applying water in agriculture. In the present study, a new procedure for field evaluation of water distribution in furrow irrigation is proposed. For this purpose, application efficiency (Ea), water requirement efficiency (Er), deep percolation (DP) and tail water ratio (TWR) have been introduced based on the average of the non-dimensional infiltrated depth values in the four data groups. The relationships between coefficient of uniformity, CU and distribution uniformity, DU have been described by opportunity time values of each quarter and using the linear equation instead of infiltration function. The proposed method was compared to other procedures by 9 scenarios of field data with different discharges and lengths. The results show that the evaluation indicators of furrow irrigation depend on the hydraulic characteristics of the soil and the opportunity time. Also, there was no observed any significant difference on the suggested indexes values and classical performance indicators.

Nowadays, in order to reduce the effect of unwanted factors and gather information related to land cover, vegetation indices were used. In this study, the effects of NDVI and VI indices on land cover and runoff curve number of Mansourabad watershed were investigated by using Geographic Information System (GIS) and Remote Sensing (RS). Land cover map was prepared by using vegetation indices and Landsat satellite images. In addition, the results of classification of these two indices and corresponding percentage with surveying data were compared. After that, runoff curve number map was prepared by combining land cover map with land use and soil hydrology group maps and by utilizing SCS table in the GIS environment. To assess the accuracy of each curve number map obtained from each index, runoff peak discharges computed by HEC_HMS model were compared by the measured amounts. The result of the classification showed that NDVI index with Kappa coefficient equal to 0.83 was better than the VI index with Kappa coefficient equal to 0.74 for land cover. These results were verified by lower error percentage between the measured and observed maximum discharge for NDVI index.

Air pollution has harmful effect on human health and the environment. Accordingly, considerable effort has been put to analyze the air pollutants. One important issue is the spatial distribution of these pollutants. Dispersion of the pollutants released from sources on the ground is mostly driven by the planetary boundary layer where turbulent flow causes mixing of the content of the stationary ground layer of atmosphere with higher moving layers and thereby clears out the pollutants rapidly. To predict the dispersion of air pollution in the atmosphere, researchers investigate the behavior of plume rise under certain conditions. Two factors critically affect the result of the test: primary plume rise and its dispersion. In this work, we study the effective height of emission which determines the dispersion of the pollutants. The height of the plume has been subjected to semi-empirical and to more accurate numerical studies. These approaches suffer from some shortcomings. For instance, the gravitational effects and fluctuations of the wind speed are neglected. Numerical approaches are typically based on a Gaussian plume rise model so called ISC3 (published by EPA). In this paper plume rise of emission of an air pollutant is simulated using Fluent software which allows one to input natural wind velocity profile and to consider the gravity. Another advantage of this approach lies in the usage of turbulent kinetic energy (TKE) and temperature profiles. In this work, theoretical plume rise using the ISC3 model were being calculated at first. The calculated values of xf and ∆h are equal to 437.85 m and 50.87m, respectively. Then, the dispersion was being simulated accordingly using Fluent and the results were compared with those of the numerical studies.

Groundwater contamination is a serious problem facing the countries. Because groundwater is vulnerable to contamination from a variety of sources, and, once contaminated, it is very difficult to restore to its original quality. The main objective of this study was evaluation of groundwater quality in Shahrekord aquifer and finding the source of the groundwater contamination. Some of the chemical parameters such as Cation, Anion, Electrical Conductivity (EC), Total Hardness (TH) and Total Dissolved Solids (TDS) were measured in four times including spring and autumn of two years. The results show that the chemical contaminant concentration in North-Western part (NWP) of the aquifer was lower than Southern part (SP). Bicarbonate in the Anions and Calcium in the Cations has the maximum value. However they are lower than the standard limits. The TH in the wells varies from 150 [1]to 300 (mg/lit/CaCo3). The water quality is classified in hard water category base on TH. The result shows that there wasn’t considerable difference in TH and TDS values on spring and autumn seasons. The maximum nitrate concentration was almost 37 mg/lit in the northern parts. The result shows that TH and TDS in the southern parts and Nitrate concentration in the northern parts were maximum values concentration. This subject shows that the source of these contaminants is different. The agricultural lands produce Nitrate contamination and the urban wastewater is source of chemical concentration and TDS

More than 98 percent of the earth’s drinking water supply comes from groundwater. It needs protection from possible contamination, especially in urban areas where wastewater production is high. Most area of Shahrekord plain is under the cultivation and irrigation water comes from the groundwater. Furthermore, urban sewage discharges to the groundwater, in some parts of the Shahrekord plain. In this study, 18 wells were selected for water sampling. The effects of landuse were evaluated on Total Dissolved Solids (TDS), Total Hardness (TH), Electrical Conductivity (EC), Nitrate (NO3–), Nitrite (NO2–) and Sulfate (SO42-). The samples were selected in different seasons; spring, summer and autumn 2004. A Nested Complete Randomized Design (NCRD) was used for statistical analysis with 18 samples per plot. The results show that there were significant differences (P<0.05) between value of NO3–, NH4+ concentration and EC in farmlands and urban areas. There was no observed any significant difference on the NO2–, pH and TH value. It was higher in farmlands than in urban areas. The result shows that there are a significant difference (P<0.01) on NO3– concentration in different seasons.