جستجوی مقالات مرتبط با کلیدواژه « شبیه سازی هیدرولیکی » در نشریات گروه « آبخیزداری، بیابان، محیط زیست، مرتع »

The main purpose of this research is to identify the behavior of rivers in the area of Lashtghan shrimp breeding site and to provide technical solutions to organize and prevent flood risks there.

In this study, HEC-RAS was used to perform hydraulic flow calculations based on unsteady flow. Calculations were done with changes in flood flow with different return periods. To determine the flood zone for the 25-year return period, the water height was transferred to ArcGIS. Using the HEC-Geo-RAS extension, the flood zone was determined in ArcGIS. To present the proposed natural bed line, satellite images at different time intervals were analyzed and the proposed bed line was extracted after verifying the flood zone with these images. The amount of technical protection was calculated using the DLSRS (Discharge Location Stability Regime Social Tension) method. The flood return period for the design was considered to be 100 years, based on economic, social, and climatic conditions. Considering the project's purpose, domain of usage, and technical and economic conditions, an earthen dike was selected for the land protection plan against floods. In Civil 3D software, the protective dike project line was defined and, according to the 100-year flood water level, the protective dike was designed.

The boundary for modeling the flow of rivers and canals leading to the Lashtghan site was established upstream of the hydrograph and downstream of the water level (2.9 meters, or 76% of the duration of the course is less than this value), based on justification studies. The observed minimum height is approximately 0.65 meters, the maximum height is 5.7 meters, and the average height is approximately 1.6 meters; these measurements are insufficient to ascertain the height of the dike. The height reached its highest and lowest values every six hours. In the northern region of the site, the maximum water level, maximum flow depth, and maximum flow speed were more apparent. The water level fluctuated between 1.2 and 35 meters, the maximum flow depth increased from 0.001 to 40 meters, and the maximum flow velocity improved from 0.00033 to 1.8 meters per second.

The model output included characteristics of the maximum flow level, depth of flow, and maximum flow velocity in the study area. It was observed that the built dike has no effect on the surrounding residential areas. Due to the topography, the earthen dike acts like a reservoir in some places, preventing downstream flow and storing water behind the dike. This reservoir has a volume of about 3 million cubic meters for a 100-year return period flood. By constructing a borrow pit near the dike, a significant part of the water can be transferred downstream. Finally, the height of the dike, the slope of the body, and the width of its crown were calculated, with the cost estimated at 72,925,000,000 million Rials.

LISFLOOD-FP belongs to a new generation of hydrodynamic models of flood simulation, which is implemented by a digital elevation map for the river and the waterways, route information and flow rates The LISFLOOD-FP features are two-dimensional hydraulic models: 1. based on raster 2. large scale 3. ease of formulation and high computational efficiency 4. simplicity of use 5. spatial adjustment of computations adaptively by the model itself 6. the ability to use the rivers with a width smaller than the dimensions of DEM pixels 7. the possibility of integration with fully distributed hydrological model such as WetSpa. These are the advantages of LISFLOOD-FP compared to other two-dimensional hydraulic models. Today, two-dimensional hydraulic models which are based on raster has become increasingly popular due to the development of personal computer processing capacity as well as ease of access to high-resolution topographic digital maps. The present study determined hydraulic behavior of flooding and water level in different return periods in Shemshak watershed using a LISFLOOD-FP two-dimensional hydraulic model. In this regard, the digital elevation model (DEM) was used with a spatial resolution of 2 meters. Finally, the data were entered into the model and analyzed. The results indicated that the model is efficient in floods simulation and showed that the river course is vulnerable against flood in one part of the main branch of Darbandsar and in the junction of Shemshak and Darbandsar in Dorood while it has less vulnerability in some other areas.

Urban watershed shows quite different hydrological and hydraulic behavior from natural watershed. Cities, that located along the Caspian coastline, have been flooded annually several times by relatively extreme storms and it creates a negative outlook in the cities. Comprehensive planning, design and management of surface water drainage systems are essential for creating a safe environment for the citizens. Computer models control urban run-off. Studying area is 39.64 (ha) that it was divided into 51 sub-basins. The simulation of flooding in urban catchment basins for this study was required information such as climatic, topographic, hydrologic regime, current status of surface water collecting network and hydraulic properties. In this study, urban flooding is simulated by MIKE SWMM model. By applying this model, in term of hydrologic and hydraulic data of the drainage systems, capability of surface water collecting system were evaluated for safe passage wandering water with design storm for 2, 4 and 6 hours and return periods of 2, 5, 10 and 25. The critical nodes and channels were identified after simulation. In result, simulation also showed that some existing water channels in this region, have not capability of passing design floods and this inability causes extra load and creates flooding condition in ending nodes over critical routs. Thereby, this long-time condition creates serious difficulties in transportation system and make inundation in the roads.

Prediction of river hydraulic behavior for probable flood is most important in flood mitigation in the urban area and for installation has been make، farmland and other land use in river environs. In the other hand، flow estimation at a point in a river is vital for a number of hydrologic applications include flood forecasting. The human impacts on river channel limitation occur in various forms، which its intensity and weakness are different in various rivers. Therefore، simulating the hydraulic behavior of the rivers، in order to predict the damage caused by floods in various conditions، river engineering projects، feasibility study، economic and social programs and flood control and other studies related to the river system is necessary. The purpose of this study is to combination the hydraulic model HEC-RAS software and Arc View GIS software using HEC-GeoRAS extension for simulating the hydraulic parameters of river Basher located in the Kohgiloyeh & Boyerahmad province. The results of this study indicate that the HEC-RAS model can provide the appropriate numerical values for investigating the hydraulic characteristics of flow in rivers and for flood hazard mapping with more accuracy and low cost used.