Showing 7 results for Karun
M. Shafai Bajestan, M. Ostad Asgari,
Volume 4, Issue 2 (7-2000)
Abstract
The application of “Modified Einstein Procedure” is recommended by the Specialized Committee on Sediment, Iranian Ministry of Energy. However, this method has not been applied to any river in the country. It is the purpose of this study to investigate the total sediment load of the Karun and Karkheh rivers at Ahwas and Hamidieh stations.
The graphical calculations of the method are very complicated and time consuming. Therefore, a mathematical model has been developed in this study to improve the accuracy, simplicity and speed of computations. The required data were obtained from the above stations for seven years (1988-95), and applying these data, the total sediment load was calculated using the model. The bed load for the above stations was also computed and the ratio of bed load to total sediment load was calculated. In addition, measured data from East Fork river (in USA) were applied to examine the accuracy of the method in estimating the bed load. Comparison of the measured and computed results shows that the “Modified Einstein Procedure” estimates the amount of bed load with a high accuracy. The relationship between the bed load and suspended load and also between the total load and the stream discharge have also been established.
Finally, it is concluded that the “Modified Einstein Procedure” with minor modifications can be successfully applied for the above-mentioned rivers of Karun and Karkheh.
M.r. Ghanbarpour , M. Teimouri, S.h. Gholami,
Volume 12, Issue 44 (7-2008)
Abstract
Estimating the volume of groundwater contribution to runoff within a watershed is one of the most important subjects in water resources management and hydrology. In this paper, groundwater contribution to total runoff as a base flow index was estimated using hydrograph separation in six stream gauging stations in southwest of Iran. The major objective of this research is to distinguish the most suitable automated hydrograph separation and base flow estimation method. Conventional automated hydrograph separation methods including local minimum and recursive digital filter with the parameter of 0.9 to 0.975 were compared with recession analysis numerically and graphically. The results showed that recursive digital filter with the parameter of 0.925 is the most accurate method to estimate base flow in the studied watersheds. This research also indicated that the base flow index estimated through the selected method varies from 0.79 to 0.88 in the study area.
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.
M. Alinezhadi, S. F. Mousavi, Kh. Hosseini,
Volume 25, Issue 1 (5-2021)
Abstract
Nowadays, the prediction of river discharge is one of the important issues in hydrology and water resources; the results of daily river discharge pattern could be used in the management of water resources and hydraulic structures and flood prediction. In this research, Gene Expression Programming (GEP), parametric Linear Regression (LR), parametric Nonlinear Regression (NLR) and non-parametric K- Nearest Neighbor (K-NN) were used to predict the average daily discharge of Karun River in Mollasani hydrometric station for the statistical period of 1967-2017. Different combinations of the recorded data were used as the input pattern to predict the mean daily river discharge. The obtained esults indicated that GEP, with R2= 0.827, RMSE= 59.45 and MAE= 26.64, had a better performance, as compared to LR, NLR and K-NN methods, at the validation stage for daily Karun River discharge prediction with 5-day lag, at the Mollasani station. Also, the performance of the models in the maximum discharge prediction showed that all models underestimated the flow discharge in most cases.
S. H. Roshun, K. Shahedi, M. Habibnejad Roshan, J. Chormanski,
Volume 25, Issue 2 (9-2021)
Abstract
The simulation of the rainfall-runoff process in the watershed has particular importance for a better understanding of hydrologic issues, water resources management, river engineering, flood control structures, and flood storage. In this study, to simulate the rainfall-runoff process, rainfall and discharge data were used in the period 1997-2017. After data qualitative control, rainfall, and discharge delays were determined using the coefficients of autocorrelation, partial autocorrelation, and cross-correlation in R Studio software. Then, the effective parameters and the optimum combination were determined by the Gamma test method and used to implement the model under three different scenarios in MATLAB software. Gamma test results showed that today's precipitation parameters, precipitation of the previous day, discharge of the previous day, and discharge of two days ago have the greatest effect on the outflow of the basin. Also, the Pt Qt-1 and Pt Pt-1 Qt-1 Qt-2 Qt-3 combinations were selected as the most suitable input combinations for modeling. The results of the modeling showed that in the support vector machine model, the Radial Base kernel Function (RBF) has a better performance than multiple and linear kernels. Also, the performance of the Artificial Neural Network model (ANN) is better than the Support Vector Machine model (SVM) with Radial Base kernel Function (RBF).
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.
R. Khalaf, A.m. Akhoond-Ali, Saeid Soltani, K. Rezazadeh,
Volume 27, Issue 1 (5-2023)
Abstract
Due to developing abstractions and their impacts on surface runoff, the recorded flow has been changed by human activities in most water gauging stations. Therefore, there is not found natural regime in the catchments. Accordingly, the objective of naturalization is to remove the effect of human activity factors and determine the actual amount of the river flow before the abstraction and the upstream development. Researchers have presented different methods that are mainly based on volume budget. In this way, this research presented the conventional methods as well as investigated their weak points. These new and innovative methods have been applied based on the available data. The methods have been planned based on the net consumption in which, the different types of water demands related to the upstream of each hydrometric station, are estimated for each month of a long-term series. Then, the amount of natural flow is determined by adding them to the observed flow. The accuracy and validation of the results are investigated by comparing the observed and calculated flow. As a case study, this method was utilized and implemented for Tireh and Marbareh sub-basins in Dez as well as Solgan and Beheshtabad sub-basins in the Karun basin. The results showed the role of the human activity factors decreasing the long-term outflow in the Tireh basin a 23.2%, in the Marbareh basin a 28.7%, in the Vanak watershed a 26%, and in the Beheshtabad basin a 9.5%. The results validation indicated the appropriate compatibility of the observational and estimated data for the control points (the stations). In this research, natural flow is obtained by presenting a practical method based on available information in the country. The proposed method has been in the preliminary stages. To verify and comprehend it, it should be used in future research on the interaction of surface and underground water and the use of new technologies such as remote sensing.
