Exploitation of underground water resources is a way to modulate the shortage of seasonal water. In this regard, proper site selection for constructing underground dam to reserve waters is a challenging issue. Thus, using an approach with minimum error is essential. The purpose of this paper was optimum selection of potential sites for constructing underground dam in Hamedan-Bahar catchment basin using a new GIS-based approach to reduce the error. For this purpose, the efficient criteria of a proper site to make underground dam were first recognized. These criteria include density of drainages, separation of the aqueducts, spring and wells, geological appropriate, slope, fault density, proximity to roads and villages and special conditions of land use. Then, different evidence layers were weighted in [0, 1] range using logistic function in geographic information system. Finally, the weighted evidence layers were integrated using geometric average function. Thus, a model representing favorable areas for making underground dam was generated. The results obtained introduced less than 10% of the streams (respecting the whole streams in the study area) as suitable, and demonstrated that the method applied can be used efficiently to delimit the study area and to recognize suitable streams for construction of underground dam.

Aim of this study is to measure shear stress in smooth rectangular and trapezoidal open channels. A new approach is presented to measure direct shear on wet perimeter of open channels. A water flume with a section on a frictionless support (called knife edge flume) along with a system of load cell was used to measure total force on the wet perimeter. The local boundary shear stress in rectangular and trapezoidal cross sections was measured using a 4mm diameter Preston tube connected to a differential pressure transducer and a data acquisition system. The calibration curves proposed by Patel were used to convert the pressure readings to shear stress. Local and total shear measurements were used to differentiate the channel wall and bed shear forces. This method allows minimizing of the error as result of the Preston tube diameter. Comparison of the results confirmed advantage of the momentum method over the energy method in term of accuracy. Results are presented for smooth rectangular and trapezoidal channel cross sections with side slopes of 1, 1.5, and 2.

Dam break wave is a phenomenon resulting from sudden release of water in a channel. Aiming at a numerical study on such waves, this paper presents a finite volume model based on shallow water equations which utilizes the Weighted Average Flux (WAF) scheme to estimate inter-cell numerical fluxes. The model has a shock capturing feature, and requires no special treatment to handle waves propagating over dry beds. Different stages of wave propagation were analyzed by offering free surface profiles for the cases studied. Furthermore, several computational tests, including comparison with the existing analytical solution as well as experimental data, are provided to confirm the performance of the model in simulating unsteady flow due to the dam break.

The purpose of this study was to evaluate the environmental risks of Alborz Dam on Babolrood River in Babol city, using MCDM methods. First, the environment of the study area was identified, then a list of identified environmental risks was prepared in the construction and exploitation phase, and in the form of a questionnaire was provided to environmental experts familiar with the Alborz dam basin. Environmental risks were rated by experts according to the Likert scoring range based on the three indicators of occurrence intensity, probability of occurrence and risk significance, then environmental risks ranking was performed using OWA method. The most important risks of Alborz dam were obtained during the construction phase: when the decision maker is risk aversion, respectively: Destruction of forest within the dam with a score of 0.048, Displacement of reservoir residents with a score of 0.047, and, When the decision maker is risky, respectively: Destruction of forest within the dam with a score of 0.051, Displacement of reservoir residents with a score of 0.050. Also, The most important risks of Alborz Dam were obtained during the operation phase: When the decision maker is risk averse, respectively: Thermal stratification of dam reservoir with a score of 0.053, Reduction of self-purification of Babelrood River with a score of 0.051, and, When the decision maker is risky, respectively: Thermal stratification of dam reservoir with a score of 0.057, Landslide with a score of 0.056.

Geophysical methods have been developed to study the particulars of physically diffusible fields in the ground. In geophysical studies, the goal is usually to detect inhomogeneities inside the earth using physical values measured at the earth's surface. Geophysicists attempt to reconstruct the Earth's interior structure using such data. The present study, which is known as the Third-order Moving Average, is the solution of an inverse problem for simultaneous estimation of the shape and depth of residual magnetic anomalies. The method was applied to the synthetic model, with and without noise, which Superiority this method will show over the Second-order Moving Average. Also, tested by the instance of fi eld data in Geological Survey of Iran (GSI). This method, calculates a nonlinear relationship between depth and shape factor, at seven points with successive window length. Finally, the results showed that this method is very accurate for non-noise data and in has good agreement with the noisy data. which the problem, will showed the superiority of the Third-order Moving Average Method over the Second-order Moving Average method for estimating the shape and depth of buried Magnetic Anomalies. It also showed that it is suitable for real data with 5% error.

The dynamic interaction of fluid-solid systems has long been a subject of interest in many engineering fields. One of the most important problems of this nature, encountered in civil engineering, is the dynamic interaction of a dam and the reservoir under seismic loading. Recent research indicates the importance of this interaction and the resulting hydrodynamic forces, including the compressibility effects of water on the seismic response of concrete dams.In this thesis a combination of 2D finite-element and a closed form method based on a Eulerian approach is developed to study the dam-reservoir interaction effect. The mentioned procedure is used to investigate the interaction effect on stresses and displacements of the Kowsar Dam-reservoir system. To establish the accuracy of the method, the seismic response of the Pine Flat Dam is studied and the results are compared with other exact solutions.

In this paper, the finitely many constraints of a fuzzy relation inequalities problem are studied and the linear objective function on the region defined by a fuzzy max-average operator is optimized. A new simplification technique which accelerates the resolution of the problem by removing the components having no effect on the solution process is given together with an algorithm and a numerical example to illustrate the steps of the problem resolution process.

More than necessary attention has been given to methods of translation skills in literary texts, and its emphasis on transmission in reading and writing as a primary necessity of language teaching. This method has now as a teaching mode gradually come under critical attack. Changes and reforms of the 20thc. and its effects upon the goals of education required a new method to meet the taste of language learners and also fulfill the requirements of teaching goals. By using study phonetics as a branch of linguistics and the priority given to listening and speaking in language teaching, a new method by the name of Direct Learning has been set up. This method has so far been used in conventional teaching classes. This paper aims to present a comparative analysis between Direct learning in the conventional system and Direct learning in electronical approach.