فهرست مطالب farhad khamchin moghaddam

Aquifers, as one of the most vulnerable water sources, are exposed to various contaminants in different forms, which detecting and controlling pollution in these resources are more difficult and costly than surface water. The best way to prevent their contamination is to identify polluting sources and vulnerable areas, prepare vulnerable zoning maps and adopt appropriate management policies. In this study, the DRASTIC and GODS methods are used to assess the Khezri area. Khezri area is one of the sub-basins of Khaf-Petergan Playa Iran, based on the political divisions of the country, and located in the southern Khorasan province near Qayen city, between the longitudes of 35 58 to 17 59 east and latitudes 41 33 to 6 34. The results of the DRASTIC for this area showed that a small part of the area has very low vulnerability, a very wide area of the plain has low vulnerability (69.68%), and the northwest and west of this plain have medium, high and very high vulnerability. Sensitivity analysis is also done in this area with two methods of eliminating the parameter and single parameter. In the single parameter sensitivity analysis, the aquifer environment parameter has the most effective weight and the parameter of the topographic slope percentage has the least effective weight in calculating the vulnerability index. In the map zoned by both methods, the points with high vulnerability are in the area of Khezri city and steel factory.

Marine Structures projects, especially the construction of oil platforms, are faced with numerous risks in different stages of design, construction and exploitation, due to factors such as the extent of resources and Uncertainties. Identification and assessment of these risks as one of the most important measures in the risk management process, will have a significant role in better planning of these projects by managers.

In this study, in order to manage the risk of oil platforms project, first, all possible risks in the fields of engineering, executive, environment and passive defense were identified in a library form, and among them,  according to experts’ opinions, 26 risks Were identified as important and effective risks on the project. Finally, to assess and prioritize the risks, multi-criteria decision-making models were used in the fuzzy mathematics environment.

In this regard, after setting the questionnaire to test the hypotheses of the research, relying on experts’ opinions, identified risks were ranked by TOPSIS model in fuzzy environment.

Survey of the resulting rankings shows that the option of incorrect design due to defect in geotechnical studies in the field of engineering,  the option of stopping executive operations due to lack of supply of providing necessary materials and equipment due to the sanctions in the Executive field, the option of arson and explosion in the field of passive defense and the option of sea water pollution in the field of environment as the most important risks affecting in each of the four areas of the project are studied.

Population growth, urbanization, and industrialization of human communities have adverse effects on basin’s hydrology. Increasing the impervious area increases the amount of surface flow coefficient, runoff and flood volumes. According to earth surface changes, one of the best human activities is the use of surface runoff for different purposes in urban area. The main purpose of this study is to investigate the use of surface runoff for irrigation of green spaces. Due to the high volume of water demand in 9th district of Mashhad, in this study, we propose to utilize the existing detention ponds (and design new detention ponds) for irrigation of the green spaces during the flood events.

The case study is located in ab-o-bargh basin with about 770 hectares area. In order to determine the dimensions and length of the canals, maps from the fava organization are employed. According to field visit as well as digit elevation, the study area is divided into 88 sub-basins. Infiltration coefficient was selected based on the soil texture of the basin (residential, street, etc.). Manning coefficient was determined as 0.015 according to the software help for the channels and its coverage for each sub-basins. The effective catchment width with a suitable approximation obtained from division of the basin area over the channel length. For calculating the average slope of the basin, the most accurate method is the use of slope pattern algorithm in GIS. Channel slope was calculated similarly with the start and end elevations of each channel. Horton and keirpich methods were used to estimate the infiltration and concentration time, respectively. Regarding the return period and rainfall pattern, the IDF curve of Mashhad was used. Two-year return period was considered for simulating flood distribution in the study area. The first step for designing flood’s design period is to select an appropriate rainfall return period. In this study, average daily water demand for irrigation of green space is equal to 3.936 m3 per day. The volume of existing reservoirs is about 1305 m3. For modeling the study area, at first, in AutoCAD software, all sub-basins and channels are defined and introduced to model separately. According to the characteristics of each layer, the physiographic data of each layers such as area, basin width, average slope, digit elevation, manning's coefficient was defined in the model. For simulating different features of the study are, ASSA software was employed. Then, the required physiographic and topography data was imported from GIS to this software. After that, precipitation data, horton coefficients, and the other metrological and hydrological data was introduced into the model.

After running the model, the discharge and the total runoff volume of flood are equal to 6.55 m3/s and 17531 m3, respectively. The total numbers and volume of available tanks are equal to seven and 1305 m3, respectively. Two tanks have 9*9*4 m3, two tanks have 6*6*3 m3 and three tanks have 7*7*3 m3 dimensions. The dimensions of the proposed detention ponds are three tanks with 9*9*4 m3 and three tanks with 7*7*3 m3 dimensions with a total volume of 1,413 m3. Results showed that without detention ponds, the runoff volume and peak was equal to 17,531 m3 and 6.55 m3/s, respectively. Using the available detention ponds in the study area, the total volume of runoff is decreased from 17531 m3 to 16298 m3, demonstrated 7% decreases in flood volume. Peak of runoff is also decreased to 5.71 m3/s, indicated 13% decreases. Moreover, by adding the proposed detention ponds, the amount of outflow runoff is decreased to 14,900 m3, which is demonstrated 9% decreases in comparison to using the available detention ponds and 15% decreases in comparison with no detention pond state.

The water scarcity crisis and water pollution are among the key issues both in the current century and in the future. Several different techniques have been introduced for the decontamination of water pollution, among which using the nanotubes is one of the most influential. In this project, the single-walled and multi-walled carbon nanotubes were employed to test the possibility of removing heavy metal ions, such as Fe2+, Cd2+, Pb2+ and Ni2+. The effects of three factors including carbon nanotubes, ions’ initial concentration, and contact time were tested. According to the difference rate of nanotubes’ adsorption diagrams, the maximum differences in the performance of single- and multi-walled are obtained as 30 percent for the initial solution concentration and around 5 percent for Nano adsorbent concentration. The results showed that in the different initial concentrations of metal ions, multiwalled nanotube had a better performance, while in case of changing the amount of adsorbent; the single-walled nanotube had a higher adsorption. And if the time changes, multi-walled carbon nanotube can have a higher adsorption

In the present research, effects of a porous spur-dyke on the hydraulic characteristics of the flow in an open-channel have been numerically studied through non-linear Forschheimer model. The numerical simulations were performed in Flow3D package using RNG k-epsilon turbulence closure model. During simulations of the porous spur-dyke, suitable Friesheimer non-linear coefficients were determined for various cases with the sensitivity analysis. The sensitivity analysis and comparisons of the numerical results with the results of the physical model showed that most of parameters are completely dependent to Friesheimer non-linear term and the proposed software range for Friesheimer nonlinear coefficient is not suitable. The results showed that by increasing of the porosity of the porous spur dyke, the flow velocity and also the effect area of the maximum velocity will decrease. Also, by increasing of the porosity of the porous spur dyke, the upstream water depth of the spur dyke will decrease and the downstream water depth of the spur dyke will increase. It was also observed that by increasing of the porosity of the porous spur dyke, the maximum value of the velocity decreases and the minimum value of it increases.

Geographical regionalization means defining and classifying different regions according to their climatic characteristics. Scientists of this field have developed various methods for this regard. De Martonne is one of these methods which works according to two factors namely annual temperature and precipitation. Geographical regionalization or defining homogeneous regions is needed in analyzing meteorological events such as temperature, precipitation, wind, flood, runoff etc. It worth noting that analysis of these factors is not possible unless all of them were related to same region, or in other words, follows a basic pattern. Nowadays, scientists have developed math-based methods, such as linear moments and homogeneity tests. The advantage of these methods over the previous ones, is that these new methods are applicable for almost all events, where as the old ones were limited to be used by only some of the events. In this study, all the meteorological stations which measured temperature and precipitation were selected. Then via linear moments and De Martonne methods, the homogeneity and discordancy of the regions were analyzed. The results gained from this analysis rejected the efficiency of De Martonne method. Besides, application of this method is not recommended in developing homogeneous regions.