Papers by Keyword: Flood Routing

Abstract: The disastrous flood that inundated many areas of the Chao Phraya basin in 2011 caused many detrimental effects on the countrys economy and society. It is vital for all concerned to better plan and manage these effects in order to minimize future disasters areas. Flood reduction requires water flow detention or deceleration of during the storm water season. The construction of water detention ponds is one solution that should be taken into account. This study investigated the reduction of water flow in Yom basin (a sub-basin of Chao Phraya basin) using the synthetic unit hydrograph to synthesize deluge parameters. The objectives of this case study are to utilize natural lowland areas upstream of Yom Basin, namely Bung Takreng, Bung Kheerang, and Bung Raman. These three swamps are adjacent to one another, so one detention pond system could be constructed. The relationship between volume (S) and height (H) of the detention pond system was found to be S=18866224.8H^1.15 based on the analysis of elevation data using Geographic Information System (GIS). The estimated inflow to the detention pond at different return periods was based on the synthetic unit hydrograph. The maximum flow rate was analyzed by flood routing through a modeled reservoir system. The reservoir system was assigned a 3 m height dyke over the spillways, dividing into 2 m for the peak drainage and 1 m freeboard. Flood routing was performed at the return periods of 2, 5, 10, 25, 50, and 100 years. We obtained the following safe lengths of spillway: 30, 70, 100, 140, 175, and 210 m, respectively. The detention pond system can detain water for 4 hr and reduce the peak flow in Yom River to 81.83, 84.44, 77.26, 81.00, 90.81, and 89.81m3/sec or 9.37, 5.75, 4.08, 3.30, 3.15, and 2.71 percent, respectively. Findings of this study can be applied in decision making regarding the construction size of the reservoirs. In addition, the results can be applied in developing other areas into detention ponds.

Abstract: The 2-D water flow mathematical model based on MIKE 21 software which reflects flood routing in the reach from Gaocun to Sunkou has been developed in this paper. Through the numerical simulation of the “96.8” typical flood, the simulating results in the condition of present topography are agreement with the measured ones. It shows that this model is basically reasonable in the selection aspects of river terrain, boundary treatment, roughness and water flow parameters, and the model has a reference value for simulating flood routing in the Lower Yellow River.

Abstract: The Lower Yellow River is apt to deposit and migrate. The reach from Huayuankou to Jiahetan is the typical wandering reach, which has broad and shallow body, intertwined tributary and numerous shoals. The mainstream always swings, and the riverbed deforms rapidly. There exist lots of residential places, irrigation canals, roads, productive dikes and other controlling works within the embankments, which greatly limits the scope of flooding. When the peak discharge is very large, the flood is prone to resulting in productive dikes bursting, which will greatly endanger the lives of residents in flood plains. The 2-D water flow mathematical model which reflects flood routing in the reach from Huayuankou to Jiahetan has been developed based on MIKE 21 software in this paper. Through the numerical simulation of the “96.8” typical flood, the simulating results in the condition of present topography are agreement with the measured ones. It shows that this model is basically reasonable in the selection aspects of river terrain, boundary treatment, roughness and water flow parameters, and the model has a reference value.

Abstract: Dam-break flood affected by highly changing and complex environment, has some characteristics including the sudden of occurrence, the rapid of expansion and the urgency of respond. This paper focuses on how to develop a virtual geographic environment (VGE) system to study the dam-break flood routing and its impact. Unlike existing work, our methods pay attention to the multidimensional and dynamic analysis methods in virtual geographic environment, which make flood routing easily understood to public and officers. Moreover, some GIS spatial analysis and real-time interactive operation with the VGE will also be implemented to support the risk assessment of the dam-break. Finally, a prototype system is developed to construct a virtual geographic environment for impact analysis of dam-break flood routing and dynamic interaction. Experimental results prove that the scheme addressed in the paper is effective and feasible.

Abstract: Through the researches and discussions of each constituents of multi-resolution watershed model, the article comes to the conclusion that could apply the LOD(Level of Detail, LOD) technique , the blanking technique and so on to the deletions and replaces of DEM(Digital Elevation Model, DEM) data nodes and the unimportant watershed region in the multi-resolution watershed model, the remote sensing images, the multi-resolution building model, the multi-resolution flood routing model. The method could reduce the data quantity of valley model. The experiment has proved that the multi-resolution watershed model with the applications of this method could not only express three dimensional virtual large scene of the watershed better, but also make the visualization of the mass data model in real-time interactive manner in condition of the computer capability nowadays. This achievement has provided the new thought for the compression of remote sensing images and data transmission of WebGIS in real-time interactive manner.