Showing 5 results for honarbakhsh
M. Fathi, A. Honarbakhsh, , M. Rostami, A. Davoudian Dehkordi,
Volume 16, Issue 62 (Winte - 2013 2013)
Abstract
The present paper tries to describe the advantage and improvement of a numerical model when predicting government processes on Flow Rivers. With regard to the important effect of the flow velocity and shear stress forces on river bank erosion, we apply a Two-Dimensional numerical model, named CCHE2D, to simulate river flow pattern at a meandering river Khoshk-e-Rud River of Farsan, 30 Km west of Shahr-e- Kord. Various algorithms and parameters were implemented in a computational fluid dynamic model (CFD) for simulation of two-dimensional (2D) water flow to gain an insight into the capabilities of the numerical model. At this surveying, at first, we applied the topographic maps of the studied location and then, made the model geometry and calculation mesh with diverse dimensions. Finally, using the measured properties of the river flow and the Depth-Average, Two-Dimensional Hydrodynamic Model was run. Then, we obtained the results of model, such as depth and flow velocity at the river meander. Within the scope of the test cases, the model simulated water flow pattern processes at an intake, as well as a steady flow regime in a sine-shaped meandering channel by a 90_channel bend, which is the free-forming meander evolution of an initially straight channel. Because of high accuracy of this numerical model and multiple content of its internal parameters, the evaluation result of model, confirmed the measurement results. Therefore, the parameters gained from the model showed good conformity with measurement parameters at field cross-section. All results matched well with the measurements. The results also showed that using computational fluid dynamics for modeling water flow is one step closer to having a universal predictor for processes in Meandering Rivers
Z. Abdollahian Dehkordi, Kh. Abdollahi, S. J. Sadatinejad, A. Honarbakhsh, M. Nekooeimehr,
Volume 19, Issue 71 (spring 2015)
Abstract
Achievement to sustainable development is dependent upon integrated watershed management. In other hand without detailed analysis of the rainfall - runoff observations, high risk of flood predictions will be translated into flood-induced capital losses. Considering the fact that not always hydrometric data are available, using synthetic unit hydrograph is one of the most popular methods of flood simulations for ungauged watersheds. This method has operational limitation for duration of runoff but in Instantaneous Unit Hydrograph (IUH) assumed to all take place at a discrete point in time therefore can be converted into and desired durations.According to literature few studies have been focused on Laplace transforms, H2U-Nash Unit Hydrograph in Iran, this work is an attempt to investigate model performance in Jooneghan catchment, located in northern part of Karoon great basin.Laplace synthetic hydrograph was derived base on effective rainfall while H2U-Nash model was simulated using moments technique and lag time.The mean absolute relative error of Laplace transforms, H2U-Nash was 0.42 and 0.25 respectively. Visual interpretation and statistical comparison of Nash-Sutcliffe efficiency coefficient of the models confirms that H2U-Nash model performs better than Laplace transforms model.
A. Honarbakhsh, M. Pajoohesh, M. Zangiabadi, M. Heydari,
Volume 21, Issue 4 (Winter 2018)
Abstract
Nowadays, human interferences in the natural resources cause the loss of these resources and lead to destructive floods, soil erosion and other various environmental, economic and social damages. Furthermore, increasing growth of population and climate change intensify the destructions. Thus management and planning through land use optimization is essential for the proper utilization, protection and revival of these resources. The purpose of this study is to couple the fuzzy goal programming and multi objective land allocation optimization approaches to develop a model for watershed management and planning in Chelgerd watershed. The proposed model is based on optimum area determination in various land uses and also their optimum local situation. In this research, a fuzzy model has been proposed. In this model, minimizing the amount of soil erosion and maximizing the amount of profit are priorities, respectively. Moreover, production resources including water and land as well as economic and social problems are limitations of the mentioned model. Results obtained show that the proposed model is an efficient model in land use optimization and sustainable area development and can increase profit to 37% and decrease sedimentation to 2.4%, respectively.
A. Honarbakhsh, M. Fathi, M. Rostami,
Volume 23, Issue 4 (Special Issue of Flood and Soil Erosion, Winter 2019)
Abstract
In general, rivers are one of the best and most accessible water resources at the disposal of mankind. So, given the effect of the force of water and changes on the flow patterns and consequently, on river morphology changes, the analysis of the flow in the river is important and necessary to organize projects, flood control and water supply structures downstream. In this study, by using numerical models CCHE2D hydraulic conditions Dimeh River Bridge between Oregon Bridge Sudjan was investigated. CCHE Model is a mathematical model capable of simulating the flow patterns and sediment transport in rivers and canals laboratory network. The numerical model in 1998, based on the calculations by the National Centre for Water Science and Engineering, University of Mississippi (NCCHE), was developed and has been applied in many research projects related to water engineering. At the outset, the input data required model provides and numerical model was implemented. In the next step, the results of the model were calibrated and validated using field data measurements; eventually, they were extracted and their model results were compared; it was confirmed that CCHE model could still simulate the flow pattern.
M. Pajoohesh, M. Mohammad Yousefi, A. Honarbakhsh, H. R. Reyahi Bakhtyari,
Volume 24, Issue 1 (Spring 2020)
Abstract
In order to plan and manage the land and its changes, it is necessary to identify and evaluate the factors affecting it. Land use / cover changes are one of the main factors in global environmental change that is defined as a change in the type of land use; it is one of the major factors changing hydrologic flow, land erosion and destruction of biodiversity. The main purpose of this study was to assess the trends of land use changes in Beheshtabad Watershed of Chaharmahal and Bakhtiari Province with an area about 3847 square kilometers by using remote sensing and GIS during a 25-year period. In this research, first, analyzing and pre-processing the satellite images of Landsat 5 TM sensors from 1991 and 2008 were done, and Landsat 8 of OLI sensor of 2016 was applied. Then, by using the hybrid classification method, 5 land use classes including pasture lands, urban-building lands, agricultural lands, garden lands and bare lands, land use maps for the three time periods were prepared. The overall accuracy of the obtained land use maps for 1991, 2008 and 2016, was 92.17%, 94.29% and 93.41%, respectively, indicating the acceptable accuracy of the maps. Then, the process of land use change and the contribution of each land use classes and the percentage of changes in each land use class were determined in two study periods. The results of this study showed some changes occurred in the studied watershed. The total area of pasture lands during two periods indicated the decreasing trend, but urban-building and garden lands during two periods represented the increasing one. Agricultural lands during the first period indicated the decreasing trend and during the second period showed the increasing trend, while bare lands during the first period showed the increasing trend and during the second period, reflected the decreasing trend. In general, it should be noted that in the Beheshtabad watershed, we could see an increase in the replacement of pastures by urban-building class, rainfed agriculture, gardens, and bare lands, the incidence of destruction in the region.
