Showing 3 results for Suspended Load
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.
A. R. Vaezi, A. Hoseinshahi, P. Abdinejad,
Volume 16, Issue 62 (3-2013)
Abstract
Flood spreading is one of the suitable methods to control the floods and conservation of soil and water in arid and semi-arid regions. Since soil properties may be influenced by the flood spreading, this study was carried out to investigate the effect of the flood spreading on physicochemical soil properties in Garacharyan plain located in North West of Zanjan in 2009. Three flooded areas and one control area were selected for soil sampling. Two hundred sixteen soil samples and twenty seven soil samples were taken from three flooded areas and control area, respectively. Soil infiltrability was also measured at three points both in the flooded areas and in control area. Results of the physical soil properties indicated that the soil infiltrability and available water content were significantly (p< 0.001) affected by the flood spreading in the study plains. With a decrease in sand percentage and an increase in clay in the flooded areas, soil infiltrability strongly declined. The available water content negatively correlated (p< 0.001) with clay in the areas. Soil chemical properties, including salinity, potassium, and bicarbonate, contrary to pH and total neutralizing carbonates and nitrogen, significantly (p< 0.001) increased in the flooded areas as compared with control area. Increasing of the salinity in the flood plains is associated with potassium in the flood plains (p< 0.001). There was no significant difference in organic matter and carbonate contents between the flooded areas and control area. The study revealed that controlling suspended load and solvent solids in the floods is necessary to prevent the degradation of the soil physicochemical properties (porosity, infiltration, plant water supply, and salinity and bicarbonate) and as a result improve the effectiveness of the flood spreading method in the flooded areas.
M. Abdi Dehkordi, A. A. Dehghani, M. Meftah, M. Kahe, M. Hesam, N. Dehghani,
Volume 18, Issue 68 (9-2014)
Abstract
In many water resource projects such as dams, flood control, navigability, river aesthetics, environmental issues and the estimation of suspended load have great importance. The complexity of sediment behavior and mathematical and physical model inability in simulation of sedimentation processes have led to the development of new technologies such as fuzzy logic which has the ability to identify nonlinear relationship between input and output variables. In this study, the application of fuzzy clustering algorithm in estimating the annual amount of sediment was studied. So, the corresponding data of flow and sediment discharge of Valykben station in kasilian basin during 1349-1350 till
1353-1354 period was daily determined. The data was divided in two groups i. e. 75% as training data and 25% for test data. Then, the efficiency of model was obtained by using statistical parameters such as correlation coefficient, nash-satklyf coefficient, mean square error root and variance ratio. The result showed that the classification of data on the annual time scale and use of fuzzy clustering algorithm can estimate 0.49 values of the measured annually suspended sediment transport. Furthermore, on the same scale of classification, i.e. annual scale, this value was obtained 0.19. Thus, using fuzzy clustering algorithm can lead to higher accuracy and reliability than rating curve method, which is suggested for estimating suspended sediment transport.
