نشریه مهندسی آب
سال نهم شماره 1 (بهار 1400)

The present study aims at investigating the groundwater reservoirs in Khanmirza Plain under drought conditions in regard of the fluctuations in the rivers leading to Khanmirza Basin using WEAP Software. In order to actualize this goal, 2007 was chosen as the base year. Then, the scenarios were evaluated within a 30-year time span (2007-2037) using the WEAP model. The results of the first scenario showed that at least 50% is required for bringing about balance in the water level of Khanmirza Plain’s aquifer through implementing a plan for reducing the area under cultivation. The second scenario shows that not only the plain does not reach a stable balance state but also the water needs of the farmlands cannot be perfectly supplied by the implementation of pressurized irrigation and increasing the irrigation efficiency in the entire plain. Moreover, the third scenario is also reflective of the insufficiency of the implementation of an artificial recharge plan on Khanmirza Plain for reaching balance in the groundwater.

The dam, like other man-made structures, may fail and cause extensive damage. In the present study, the parameters resulting from the failure of Ghare Aghach dam have been evaluated. The results showed that with the Froehlich method and the failure of the peak flow overtopping type equivalent to 9170.4 cubic meters per second, the failure of the peak flow piping type will be equal to 2383.4 cubic meters per second. With the BREACH model and the failure of the overtopping type, the peak flow is equal to 15654.7 cubic meters per second and if the failure is of the piping type, the peak flow will be equal to 1722.3 cubic meters per second. Although the BREACH model is more accurate, However, considering that the peak flow obtained by Froehlich method is 0.9792 with the peak flow observed from the BREACH model, so it has acceptable accuracy. Failure of the overtopping dam compared to the leakage condition at the level of 2444 from the dam body has a higher peak flow and will lead to financial losses as well as more casualties in the downstream area of the dam.

Local scouring around the bridge piers is one of the causes of their destruction. Therefore, in order to reduce and control this phenomenon, extensive research has been done and solutions in this regard have been presented. These solutions consist of two parts, direct and indirect, which in this study by defining scenarios, reviewing both methods and their simultaneous impact was done. In this study, the method of using cable, which changes the flow pattern around the base, was considered as an indirect and groundwater method that causes the flow lines to deviate from the substrate, as a direct method. Therefore, different states of the foundation, in front of the base, behind the base and the cable around the base with relative steps equal to 0.33, 0.5 and 0.67 in clear water conditions were investigated. According to comparative experiments, the use of a waterfront in the front results in an average scouring depth of 15 to 20% less than a footstool in the back of the base. Therefore, in general, according to the diagrams, it can be concluded that the combined use of cable and groundwater has reduced the scour depth and is accepted as a method of reducing the base scour depth.

Thermal energy in the air, causing the evaporation of water in the hydrosphere Tremblay and This action continues until saturation the air from the water vapor. evaporate maybe accur from surface water or from wet soil or transpiration from the plants. a common method to estimate ( ) is using class A pan Evaporation, In this case, multiplying of evaporation from class A pan Evaporation in pan coefficient (Kp) can be achieved (ET0). Pan coefficient (Kp) depends on the location and weather conditions. There are several ways to estimate evaporation pan Coefficient that in all of them is used from daily mean of wind speed (U), relative humidity (H) and the cover (F). The purpose of this research is to find the best evaporation pan coefficient method in Islamabad-Gharb Area, between empirical methods Doorenbos And Pruitt (1977), the Cuenca (1989), the Allen and Pruitt (1991), Model Schneider (1992), model Pereira et al. (1995), the Orang (1998) and the FAO 56 (Allen et al. (1998)) according to the data of meteorological stations Islamabad-Gharb and Compare them with Kp values obtained by dividing the . The values of ET0 are extracted from the lysimetric data from 1395. The results showed that Orang model with a correlation coefficient of 0.99, the root mean square difference of 0.008, efficiency or performance of 0.98 and the mean percentage error (0.003) is much less than other methods shows better and The coefficient of determination show the suitability of the Orang method (0.98).

The purpose of this paper was to Environmental risks Assessment of the Construction Project using the EFMEA Method with Emphasis on the risks affecting water pollution. In this study, through field visits to the construction project, the project activities were fully identified and then the environmental risks were identified. In order to estimate the amount of risks, according to experts, checks and tables, the EFMEA method was used. Following the work process, solutions and control measures were presented and the risk number was recalculated. According to the results of this study, the highest number of risks was related to secondary accidents (250) and the lowest number of risks was related to manual freight transport activity (8). After presenting control measures, it was observed that the numerical value of environmental risks, especially risks affecting water pollution has decreased.

Studies on hydraulic structures, especially around bridge piers, show that one of the main causes of bridge destruction is local turbulence. In order to have an economical and reliable design, the maximum scouring depth around the foundations must be achieved. Estimation of the maximum scour depth is necessary in order to determine the required depth for the bridge piers, because otherwise it may lead to the destruction of the bridge. In this research, SSIIM software has been used, which considers flow and sediment equations in three dimensions. In this software, the flow field is obtained from the Navier-Stokes equations and the εK-turbulence model, and then, using the non-permanent solution of the sediment field and the continuity equation, the floor level changes around the bridge pier are calculated. The results of this study show that the numerical model used, which is one of the three-dimensional models available to engineers, predicts acceptable values ​​in flow simulation, calculation of free surface and calculation of bed topographic changes in the river. In some places the speed calculation error increases, but the model is able to model the distribution of velocity and rotational currents well. From the presented models, it was proved that under the same conditions, the scour around the square and cylindrical base is more than the rectangular base.

One of the practical solutions for water resources management is to estimate the plant's water needs and determine the amount of water consumed at different stages of crop production. In order to calculate the amount of water consumed by agricultural products in the growth stages, the virtual water index and water footprint are used. In this study, first the water requirement of sugar beet, potato, forage corn and tomato plants was calculated, then the average volume of water consumption, virtual water, water footprint and water use efficiency of these products for the statistical period 2010-2017 were obtained. The results showed that among the studied crops, potatoes with the amount of 2101.291 m3/ton had the highest water footprint and sugar beet with the amount of 1094.68 m3/ton had the lowest water footprint. The highest amount of virtual water consumed was related to fodder corn (0.39 m3/kg) and the lowest amount was related to tomatoes (0.19 m3/kg). The lowest water use efficiency (2.82 kg/m3/ha) also belonged to sugar beet. Also in this study, another component of water footprint called white water footprint was examined, according to which the highest amount was related to potatoes with the amount (2006.7 m3/kg) and the lowest amount was related to sugar beet with the amount of (1003/833 m3/kg). Therefore, according to the obtained results, it can be said that the tomato crop is more suitable for cultivation than other crops in the study area due to its low virtual water content and high water consumption efficiency.