Showing 42 results for Dam
R. Lalehzari, S. H. Tabatabaei,
Volume 17, Issue 65 (12-2013)
Abstract
Shahrekord aquifer is depleted by almost 800 deep and semi-deep wells, the majority of which are agricultural wells and some have urban usage. In southern parts of the plain, the water table has fallen strongly because of immoderate discharge and decreased the quality of water by urban wastewater. The main objective of this study is investigation of subsurface dam construction and its effects on water table in consumption locations, reduction of deliveries costs and interception of contaminant transport. Therefore, the Shahrekord aquifer model was simulated with hydrodynamic coefficients calibration by PMWIN5.3 Software. The southern outlet of plain (near Bahram-Abad village) was selected to study subsurface dam construction, then a horizontal-flow barrier in this place was set with mean hydraulic conductivity equal to 0.5 m/day. Water table situation and nitrate concentration were analyzed using ArcGIS9.2 software before and after dam construction. The results showed that the subsurface dam rises groundwater level in 4 kilometers distance of upstream areas. Also, the available volume of water increased about 1.5 Mm3. Nitrate concentration didn't show to be considerably different from the initial state. But, it is likely that contamination in the storage resource will rise because it is located near Shahrekord water treatment plant and also due to the discharge of wastewater wells.
S. A. A. Hashemi,
Volume 17, Issue 66 (2-2014)
Abstract
Check dams are considered as main measures for flood and sediment control in watersheds, and their uses have been rapidly increased from 1990 onward in Iran. This research is done in Darjazin watershed in north of semnan city. The check dams have been constructed from 15 years ago in two sub basins of the watershed for flood control in Mahdishar. More than 650 check dams were evaluated for effects on flood. The collected data in the field was fed to ArcGIS software. The effects of these structures on flood reduction were evaluated by HEC-GeoHMS extension and HEC-HMS model. Because of homogeneity of watershed management projects in the basin due to building more check-dams in different watercourses, any flood discharge is related to check dams. Evaluating the effects of check dams on flood by t-test showed significant differences between flood discharge before and after construction of check dams at 5 percent level. So, check dams have been able to reduce flood discharge by 16.7 percent on average.
H. Daliran Firouz, F. Mokhtari, S. Soltani , S. A. Mousavi,
Volume 19, Issue 74 (1-2016)
Abstract
Floods are considered as most destructive among all natural hazards which impose lots of damages on human societies. Hence, it is important to estimate such damages and losses and to determine flood impact areas for management plans. HEC-FIA software as a new model (Sep. 2012) was used in Ghohrood and Ghamsar watershed basins to estimate flood-driven losses and impacts. In this model, HEC-RAS and HEC-Geo RAS are used to produce inundation map in different return periods of flood as HEC-DSS file and by using the data collected in relation to regional agricultural land, building and human, human and financial losses are directly estimated. According to the results of this model, agriculture, building and human losses respectively in Ghohrood watershed are about 354 million rials with 24 buildings affected, and in Ghamsar watershed this is about 12879 million rials with 36 buildings damaged. The advantages of this model over the previous models are estimating the direct economic and human losses for what has occurred and for possible floods in the future. The results can help with watershed management, flood insurance and risk management.
M. Khalaji, E. Ebrahimi Dorche, H. Hasheminejad,
Volume 21, Issue 1 (6-2017)
Abstract
Water quality assessment is important in late years coincide white decreas quantity it. The Zayande-Rood's Dam Lake is one of the important water resources that supplies drinking water for human populations in Isfahan, This lake also supplies water resources for agricultural sections of these provinces. Five points were determined as the sampling stations. Samplings were performed from May, 2013 to March, 2014 in seven steps, once every forty five days in for seasons (two times in each season). The water quality parameters (DO, NO3, NO2, EC, pH, hardness, TDS, NH4, BOD5) were measured in all the stations and stages, and then water quality indexes were calculated. According to the results of this study, the water quality of the Zayande-Rood's Dam Lake estimated as good (50-100), with using WQI index. WQI index maximum was in summer (84.63) and minimum was in autumn (66.4). Considering the importance of the Zayande-rood's dam lake as a supplying resource of drinkable water of Isfahan. It seems that further attention in the lake watershed management is needed in order to protect water quality.
J. Chezgi, H. Maleki Nezhad, M. R. Ekhtesasi, M. Nakhaei,
Volume 22, Issue 1 (6-2018)
Abstract
Underground dams are structures built in underground and are capable of saving and making the underground water available. In this research, by using the SWOT analysis model, suitable locations were investigated for the development of an underground dam in the Keriyan area of Hormozgan province. At first, the necessary data and information were provided by visiting the region and presenting a questionnaire to the residents of the area and experts to investigate the strengths, weaknesses, opportunities and threats in the region for the underground dams. In the final step, by using the SWOT model and QSPM matrix, a comprehensive and appropriate strategy for underground dams was determined. The results showed that among the internal factors, not decreasing the volume of the reservoir due to deposits and reducing the evaporation from the reservoir with a final value of 0.85 and 0.66, and among the external factors, the willingness and cooperation of the relevant organizations and the disruption of downstream water rights with a final value of 0.68 and 0.66 had the greatest impact on selecting the strategy. Based on the results related to the internal and external factors, the strategy was placed in the maximum-maximum quadrant; in line with the strategy, by using the strengths and opportunities, the weaknesses should be overcome and the threats should be tackled. Some strategies were presented. In order to prioritize these strategies, the quantitative matrix QSPM was used. Finally, the hydrological, economic, social and environmental evaluating strategies of underground dams, before and after the construction, with a final score of 19.3 were prioritized.
S. Salehi, Sh. Esmael Zade, Gh. Panahi, K. Esmaili,
Volume 22, Issue 4 (12-2018)
Abstract
The effect of the uplift force in the hydraulics structures is against stability. So, determining and controlling this force can be very important. One of the ways to achieve this purpose is to decrease this force by using the hole drains; in this way, we can build perpendicular pipes with different diameters, leading to the durability of the structure. Therefore, an experimental model of concrete dam was constructed in the hydraulic laboratory. The dam's model was divided into five sections by using 4-hole drains with a thickness equal to the dam's foundation. By running experiments with the maximum water level at the upstream, dam hole drains were opened in their position. Hydraulic potential was estimated by using the Piezometer built in the flume body. Finally, by opening some hole drains, the uplift force was calculated from the equipotential lines. Therefore, the best case (which had the minimum force) was determined, which was a/L=0.4, to create the most proper hole drain in the dam foundation. (a: distance of drain to heel and L: length of the dam's foundation). To place the hole drain in this position, by applying the zero potential in this position, the up lift force was increased
A. Khatoon Abadi, E. Parvizi, M. Ataie,
Volume 22, Issue 4 (12-2018)
Abstract
In the recent decades, dams have paradoxically been considered as a constraint and or a driving force of surface water conservation. On the other hand, dams have had a number of socio-economic and environmental impacts, the main reason for conducting the current case study on Shah-Qasem Dam in Yasouj, Iran, was to employ the survey field research through a questionnaire to assess the rural peoples’ viewpoint; this was done in four villages of the Southern Sar’roud County. Based on the (Cochran) formula, 192 individuals were relatively selected from each village. According to the findings, the most important impact of the dam was mainly economical (the average impact was between 2.37 and 3.7), whereas the least one was environmental (the average impact was between 1.81 and 3.54). Also, the results of the hypotheses’ analyses by means of 2 and Wilcoxon showed the following results: rise of the villages’ income, increase of the cultivated farms, increase in the employed individuals, enhancement of the cultivated crops, the regions production rising, improved tourism, lack of people’s participation in the decision making process, and reaming of the same plant varieties in the area, as compared with the pre-dam era. It is worth considering, however, that based on the statistical population used, this study was concerned mainly with the short benefits of the dam, rather than its long-term destructive ones.
F. Salmasi, H. Hakimi Khansar, B. Norani,
Volume 22, Issue 4 (12-2018)
Abstract
Modeling of Kaboodval Dam using Plaxis software has been used for the Mouher-Columb behavior model. The effect of two continuities of embankment and watering operations on the meeting was considered. The body structure of the dam was increased from the side of the faces to the middle sections, and the maximum seating was recorded at 25-25 and at about 2200 mm. By examining at different intervals, the largest meeting was in the range of 180 to 185. That is, the level of the embankment was found to be critical in these numbers. Most concerns were regarding the middle of the dam, which had a weaker position. According to the analysis of different parts of Kaboudvall Dam, the materials forming the right wing of the dam in the middle and left wings of the dam were better. In the case of the 19th Module, besides the Mouher-Columb model, the dam could be modeled with hardening and hardening models. Here, the hardening model created a better fit. The hardening model, as it could get more data from the soil, is likely to better model the behavior of the soil dams. Due to the fact that, during the construction, the first sessions usually occur, the hardening model can have a better performance.
N. Alian, M. M. Ahmadi, B. Bakhtiari,
Volume 23, Issue 4 (12-2019)
Abstract
One of the most important problems in flood manegment is the damages induced by this phenomenon. Expected annual damage (EAD) is an important index for basin vulnerability against flood. Prediction of flood damages requires the analysis of spatial and temporal risk and must be calculated by the combination of hydrologic, hydraulic and economic models. In this research, the uncertainty was considered in the flood risk analysis. The probability of flood occurrence was calculated by the parabolistic model. By using the river analysis systems software (HEC-RAS) and the geographic information system (GIS) and utilizing the Google-Earth software, the floodplains of Zayande Roud river in Esfahan province were investigated with the return period of 25, 50, 100, 200 and 500 years. The Monte Carlo method was also sed to perform the uncertainty analysis in the proposed method. The logarithmic persion type III was selected as the best distribution of flood. The damage-stage relationship was calculated as well. Based on the uncertinity analysis, the river discharge could be regarded as the major parameter in the uncertainty of EAD.
E. Ebrahimi, M. Zare Shahraki, O. Farhadian, Y. Keivany,
Volume 23, Issue 4 (12-2019)
Abstract
Benthos play an important role in the transmission of primary production and organic material (detritus) accumulation of the substrate in the water ecosystems to the higher levels of food chain. Also, they are used as biological indicators to evaluate the effect of pollutants caused by human activities on water ecosystems. To evaluate the benthic communities of Zayanderood Dam Lake, 4 sampling stations were selected on the lake; then, during the year 2014, seasonal sampling at each station was performed. The sampling was carried out by using the sediment sampler instrument with the dimensions of (20 cm × 20 cm). The average temperature of surface and deep water in the Zayanderood Dam Lake during the study was estimated to be 15.6 ± 2.4 and 8.9 ± 1.8°C, respectively. The average concentration of dissolved oxygen in the surface and deep water was varied from 10.3 ± 0.6 to 8.1 ± 0.7 mg/L, respectively. Totally, 2165 samples of benthos were collected and identified in the Zayanderood Dam Lake, belonging to 3 classes, 6 orders and 5 families. The maximum number of samples belonged to Tubifex, Naididae and Chironomidae genera. The dominant genus was Tubifex in all stages. According to this study, therefore, it seems that the structure of substrate, the amount of nutrients, grazing pressure and hydrostatic pressure are the most important environmental factors that can affect benthic community in the Zayanderood Dam Lake.
K. Mohammadi Babadi, A. Nikbakht Shahbazi, H. Fathian,
Volume 24, Issue 2 (7-2020)
Abstract
The purpose of this study was to investigate the relationship between time and spatial features of meteorological, hydrological and agricultural droughts in Karoon 1 Dam basin. Meteorological and statistical data were accordingly selected to evaluate the drought situation between 1993 and 2016. The results showed that hydrological droughts occurred in the meteorological drought and had a very high correlation with this year's meteorological drought. The most severe droughts occurred between 2006 and 2011. Studies also showed that every three years, the basin was accompanied by a meteorological drought and then a hydrological drought. The results also showed that the highest correlation was observed with the 12-month meteorological index, with a delay of 3 months, and the 6-month meteorological and hydrological index with a delay of 3 months and a three-month hydrological drought index with a delay of two months. Therefore, it could be concluded that hydrological droughts showed a delay of almost two to three months in the entire catchment area; since this period was 4 months or more, the correlation between these two indicators was eliminated and decreased. Also, due to drought zones, during the period from 1993 to 2009, most of the droughts were caused by rainfall reduction in the southwest of the province, and this was associated with a reduction in runoff in its hydrometric stations. Of course, in 2009-2012, the runoff status had been temporarily improved, and from 2012 to 2017, the drought situation had again returned spatially to the previous routine.
A. Donyaii, A. Sarraf, H. Ahmadi,
Volume 24, Issue 4 (11-2020)
Abstract
Optimizing the water resources operation, especially in the agricultural sector, which has the largest share in the water resources operation, is extremely important. Therefore, in this research, while introducing Whale, Gray Wolf and Crow Search Optimization Algorithms, their performance in the optimum operation of Golestan single-reservoir system Dam was evaluated with the aim of providing water demand for the downstream lands based on reliability, Reversibility, and vulnerability indices. In this optimization problem, the objective function was defined as the minimization of the total deficiency during the operation period. Meanwhile, the constraints of continuity equation, overflow, storage and reservoir release volume were applied to the objective function of the problem. Then, the results were compared with the absolute optimal value based on the nonlinear programming method obtained from GAMS software; finally, a multi-criteria decision-making model was developed to rank the optimization algorithms in terms of performance. The absolute optimal response obtained by the GAMS software based on the nonlinear programming method was 19.41. The results showed that the Gray Wolf algorithm performed better than the other algorithms in optimizing the objective function, so that the average responses in Gray Wolf, Crow Search and Whale algorithms were 92, 84 and 67% of the absolute optimal response, respectively. Furthermore, the Gray Wolf optimization algorithm performs better than the Whale and Crow Search algorithms in all parameters. In addition, the coefficient of variation of the responses obtained by the Gray Wolf algorithm is 2 and 1.43 times smaller than that in the Whale and Crow Search Algorithms, respectively. Finally, the results of the multi-criteria decision-making model showed that the gray wolf algorithm had the first rank, as compared to the other two algorithms studied in solving the problem of the optimal operation of the Golestan dam reservoir.
M. Pajouhesh, H. Shekohideh, Z. Heydari,
Volume 25, Issue 3 (12-2021)
Abstract
Land use changes identifying to assess and monitor sensitive areas for sustainable planning and land management is essential. Remote sensing and the use of GIS technology as some of the most common methods in the world in monitoring land changes, especially, in the study of large areas. In this study, the trend of spatial land use changes in the area of Karun 3 dam was investigated. in the before and after the construction periods and dam intake using remote sensing and GIS over 27 years. In this study, the satellite imagery of Landsat 5 TM sensors from 1991 and 2008 and Landsat 8 OLI sensors in 2018 were analyzed and processed. Using object-oriented classification with land use maps for the three periods 1991, 2008, and 2018 with the overall accuracy of the Kappa index of 0.93 and 0.89 percent for 1991, 0.94, and 0.88 percent in 2008 and 0.93, respectively, and 0.86% in 2018 was prepared. The results showed that the water use of the region with an area of 37.68 square kilometers is increasing and agricultural lands and residential areas with an area of 1349.04 and 226.56, respectively, forest lands with an area of 1041.49 remained as the dominant cover of the region and rangelands by going through a decreasing trend of increase in both periods after forest use, with an area of 878.87, they had the largest area. According to the obtained results, it can be said that the construction of the Karun 3 dam has caused the flooding of agricultural lands and their conversion to another use, as a result of which the villagers were forced to migrate due to losing their jobs and abandoned residential areas become other uses.
M. Pakmanesh, H. Mousavi Jahromi, A. Khosrojerdi, H. Hassanpour Darvishi, Hossein Babazadeh,
Volume 25, Issue 3 (12-2021)
Abstract
The present study is investigated the earth dam stability during drawdown based on both numerical and experimental aspects. To validate the numerical model, a model was performed experimentally. Some soil mechanic tests were carried out through the hydraulic experiments to attain the usage factors of the numerical investigation. To investigate the effect of hydraulic conductivity on the rapid drop of water level and the use of hydraulic parameters of materials, seepage flow in the model was modeled by seep/w software. The input information to the software including hydraulic conductivity and water volume were measured by performing a constant load test and using a disc penetration meter, respectively. After validation of hydraulic conductivity with the experimental model, the results were compared with observed data. Comparison between numerical and laboratory discharge illustrated that the numerical model with laboratory model is well confirmed. In addition, saturated and unsaturated simulations demonstrated that the unsaturated model is highly consistent with the experimental model. It is assumed that due to the drawdown conditions, unsaturated models can achieve high accuracy for simulating the flow through a homogeneous earth dam.
S. Salehi, A.r Esmaili, K. Esmaili,
Volume 25, Issue 4 (12-2021)
Abstract
The objective of this study was to investigate how the earth dam is destroyed due to the effect of upstream and downstream slope of the body in overflow conditions. Therefore, eight models were provided that each model is constructed from the embankment dam with different upstream and downstream slopes (1:1, 2:1) and the soil properties (Sc) on breach formation. The time and method of dam break for flood discharges were investigated. The results showed that the upstream side slope of the embankment dam has less effect than the downstream side slope on the scour process resulting from the phenomenon and by increasing the downstream side slope of the embankment dam, the amount of erosion in the scour hole increases 28 %. Then, using nonlinear regression, relationships were presented to estimate the output flow rate and the location of the waterfall. A to the erosion and formation of the waterfall inside the body of sticky earth dams, two main outlines of the great waterfall and a series of waterfalls were presented. Finally, the formation of these waterfalls due to the effect of shear stress created during sediment erosion relative to the critical shear stress of the dam constituents was investigated and evaluated. Considering the limitations based on shear stress, the formation status of the type and the leaching pattern of the body of the cohesive earth dams during the overpass were estimated. Then, a general plan was presented to predict the behavior of the overflow stream in homogeneous and sticky soil.
S. Ebrahimiyan, M. Nohtani, H. Sadeghi Mazidi, E. Soheili,
Volume 26, Issue 1 (5-2022)
Abstract
The basis of land management is the geomorphological zoning of the land surface, which is determined based on the same geomorphological characteristics of the zoning. Ground zoning detect land features by basic surface features such as height, slope, and slope direction. In this study, quantitative zoning of the land surface with small coefficients to the surface has been used to identify suitable areas for artificial feeding in the mountainous region of Gohar and Dasht-e Gorbayegan in Fars province. Quantitative zoning of the land surface has been performed by Evans-Shri coefficients due to the accurate determination and separation of types, faces, and surface features of the land has an important role in determining the exact land use. In this research basic models included linear, circular, and divergent models. These basic models with the dimensions of the final windows are ranked second in the MATLAB software to the level the ground is fitted to determine the fit of these models, the parameter of total squared difference has been used. In addition, the suitability of the study area for flood distribution in five different classes was determined using fuzzy logic. The most suitable areas for feeding downstream of the cones had five parameters with a maximum score of 20. The inappropriate class related to the lower plains of alluvial fans have a minimum score of five input classes in fuzzy logic, which is equal to zero.
H. Hakimi Khansar, A. Hosseinzadeh Dalir, J. Parsa, J. Shiri,
Volume 26, Issue 2 (9-2022)
Abstract
Accurate prediction of pore water pressure in the body of earth dams during construction with accurate methods is one of the most important components in managing the stability of earth dams. The main objective of this research is to develop hybrid models based on fuzzy neural inference systems and meta-heuristic optimization algorithms. In this regard, the fuzzy neural inference system and optimizing meta-heuristic algorithms including genetic algorithms (GA), particle swarm optimization algorithm (PSO), differential evolution algorithm (DE), ant colony optimization algorithm (ACOR), harmony search algorithm (HS), imperialist competitive algorithm (ICA), firefly algorithm (FA), and grey wolf optimizer algorithm (GWO) were used to improve training system. Three features including fill level, dam construction time, and reservoir level (dewatering) obtained from the dam instrumentation were selected as the inputs of hybrid models. The results showed that the hybrid model of the genetic algorithm in the test period had the best performance compared to other optimization algorithms with values of R2, RMSE, NRMSE, and MAE equal to 0.9540, 0.0866, 0.1232, and 0.0345, respectively. Also, ANFIS-GA, ANFIS-PSO, ANFIS-ICA, and ANFIS-HS hybrid algorithms performed better than ANFIS-GWO, ANFIS-FA, ANFIS-ACORE, and ANFIS-DE in improving ANFIS network training and predicting pore water pressure in the body earthen dams at the time of construction.
M. Seifollahi, S. Abbasi, M.a. Lotfollahi-Yaghin, R. Daneshfaraz, F. Kalateh, M. Fahimi-Farzam,
Volume 26, Issue 2 (9-2022)
Abstract
Unpredictable settlement of earth dams has led researchers to develop new methods such as artificial neural networks, wavelet theory, fuzzy logic, and a combination of them. These methods do not require time-consuming analyses for estimation. In this research, the amount of settlement in rockfill dams with a central core has been estimated using artificial intelligence methods. The data of 35 rockfill dams with a central core were used to train and validate the models. The artificial neural network, wavelet transform model, and fuzzy-neural adaptive inference system are the proposed models which were used in the present study. According to the results, the best model for an artificial neural network had two hidden layers, the first layer of 18 neurons and the second layer of 7 neurons, with the Tansig-Tansig activation function, with a coefficient of determination R2=0.4969. The best model for the fuzzy-neural inference system had the ring function (Dsigmoid) as a membership function, with three membership functions and 142 repetitions with a coefficient of determination R2=0.2860. Also, combining wavelet-neural network conversion with the coif2 wavelet function due to the more adaptation this function has to the input variables, the better the performance, and this function, with a coefficient of determination R2=0.9447, had the highest accuracy compared to other models.
M. Kyanpoor Kal Khajeh, Me. Pajouhesh, S. Emamgolizadeh,
Volume 26, Issue 3 (12-2022)
Abstract
Humans are always trying to change land to use natural resources to meet their needs. One of the land use changes that take place in order to benefit from sustainable water resources is dam construction. Dam construction has many positive and negative consequences for the environment from the beginning to use. The objective of this study was to investigate the effect of Gotvand Dam on the problem of collision of water flow path with salt domes and large volume accumulation of salt behind the dam lake. Images of the Landsat 5 satellite TM sensor for 1991, Landsat 7 satellite ETM+ sensor for 2008, and Landsat 8 satellite OLI sensor for 2020 were used to classify images, and prepare land use maps of the studied basin. Reviewing and evaluating the land use maps of the study area showed that agricultural lands are being developed after the operation of the dam. Also, barren lands were decreasing as well as the area's water content was increasing during the study period. In the second period of study (2008-2020), the population of the regions with an increasing area has been increasing. Also, the rangeland and meadows had a decreasing trend during the first and second periods. The results of classification accuracy using the object-oriented method for three periods of 1991, 2008, and 2020 were obtained as 0.92, 0.97, and 0.93, respectively. In general, it can be stated that the construction of the dam has increased the area under cultivation of land and by increasing population and urbanization in the construction area of the dam, destruction and reduction of rangelands occurred.
H. Azadbeygi, M. Najarchi, Dr H. Lajevardi,
Volume 27, Issue 4 (12-2023)
Abstract
The present research explores the experimental and numerical investigation of homogeneous earth dams in rapid drawdown conditions. The numerical model was evaluated and calibrated due to the saturation status using the experimental model. The calculated error between the piezometric pressure data and the seepage line in the numerical and experimental model indicated that the results of the Seep/W numerical model data had acceptable accuracy. Also, to determine the thickness of the filter adjusted in the upstream side slope of the homogeneous earth dam in rapid drawdown condition, input data to the numerical model including hydraulic conductivity, rate of the water level drop (depletion of the dam reservoir in three scenarios of 2, 3, and 4 days), the different side slopes of the body (m = 1, 2, and 3), and the thickness of the filter layers were determined. It is worth mentioning that the number of layers and the soil properties of the filter materials were determined based on the USBR which consisted of three types of soil structure (sand, gravel, and gravel with sand). The maximum hydraulic gradient of the dam materials was used to estimate the thickness of the filter layers. Finally, some dimensional fewer numbers were presented to estimate the filter layers by changing the input data through the numerical model to attain the safe conditions for the values of the hydraulic gradient at the upstream side slope. Results of the numerical model indicated that for the construction of the dam with the thickness of the presented filter, the values of the available hydraulic gradient at the point of water exit from the upstream side slope of the body of the earth dam were lower than the critical hydraulic gradient of the earth dam materials in rapid drawdown condition.
