Study On Flood Hazard Mapping Based On MIKE11 Flood Routing Mathematical Model

Flood hazard map is an important flood control non-engineering measures, it contains flood disasters, assessment of the economic losses and hedging scheme such as a series of information.It has a very important role in the relevant departments to formulate flood control planning, reducing flood disaster losses, determining to avoid transfer program in flood,formulating relevant insurance rates end enhancing people’s consciousness of flood prevention. Compared with foreign countries, our country flood hazard map technology started relatively later, but it has made great progresshad under the strong support of the Ministry of water resources and the State Flood Control Headquarters.It has gradually formed a nationwide flood simulation simulation technology, GIS technology, database theory and flood hazard map query into one unified system.It is also valuable for achieving modern flood risk management.The research object to Shaanxi province flood control key county Lueyang County is based on MIKE11 1d mathematical model of hydraulics.Through using GIS technology and related auxiliary software, flooded range and depth distribution of graphics were extracted.After analysing the flood impact and loss of Lueyang County in the different magnitude floods,the paragraph formulate the avoiding flood transfer scheme and draw Lueyang County flood hazard map.The details of the research result are listed as follow:(1)Analysis of flood inundation.Through collecting terrain data, network information and upper and lower boundary conditions,it bulit a mathematical model of 1d mathematical model of hydraulics and confirm parameters;(2)According to the flood source, flood magnitude and flood combination mode, the flood analysis scheme was determined and the result of the calculation model was calculated.The flood inundated area and water depth were obtained by GIS technology;(3)Flood impact analysis and loss assessment,respectively, to form the hydrologic flood character and social economic characteristics of grid using GIS technology and spatial superposition of the two flood influence spatial information grid model was established, namely disaster statistics model. Then, according to the typical flood loss rate database of the flood magnitude in residential property, agriculture, forestry, animal husbandry and fishery, industrial and commercial enterprises, transportation and other aspects of the flood loss to carry on the estimate analysis.(4)Hedge transfer analysis.Based on the flood inundated area and water depth, the basic information,also combined through on-site investigation, survey, interviews, local flood control plan of flood submerged within the scope of population distribution and its composition, transfer road, safety facilities, district and placement information,the following paper carried out the determination of the flood diversion unit, planning and placement sites, programming the transfer line.(5)Drawing flood risk map, through on the base map and processing, to create a scheme, the program editing, processing and adjustment process, drawing flood risk map.The main research conclusions of this paper:(1) The model parameter is 0.038, which meets the requirement of flood accuracy,Model simulation is better.(2) From the results of the flood water level show,The Jialing River and its tributaries to the highest levels of Hmax from upstream to downstream gradually decreasing fits flood evolution general rule; With the flood magnitude becomes larger, the peak flow and the highest water level becomes larger;The confluence of Jialing River, Badu River, Dongdu River from the Jialing River backwater effect,The 100 year flood confluence section Hmax height is about 652 m, on both sides of the floods caused by serious threat.From the submerged area map, submerged depth map can be seen, the different schemes of the submerged area is not large, but the overall scope of the flooded area, which is consistent with the terrain characteristics of the area. The 100 year flood inundated area, covering a large area on both sides, the area of 5.45km2, the largest submerged depth is 21 m. A serious threat to the local social and economic development;(3) Statistics from the flood impact analysis results show, Lueyang county urban district towns affected by the flood is the most serious, the affected index value for maximum, and accounted for the proportion of the total effect is larger; with the increase in flood magnitude, flooded houses area and affected GDP growth relatively fast, residents of housing and GDP more easily by flooding effect. Therefore, the relevant departments to prepare well in advance of flood control and disaster reduction;Statistics from the loss assessment of flood analysis results show that, under different flooding scheme, loss of family property and the loss of family housing accounted for the total loss of the ratio of the maximum, the effect of visible flood disaster of people is most serious, at the same time, Lueyang County by hilly type terrain conditions and the special geographical position vulnerable to the threat of flood disaster, in the floods of different magnitude, depth of 3M above the loss index values are maximum side also verified this point;(4) from the analysis of the results of the transfer of the flood, Lueyang County, the area of the transfer of a total of 5.45km2,the total population of thirteen thousand and two hundred people. According to the requirements of the local flood control plan, a total of 12 resettlement areas within the county, 8 transfer units, resettlement area can accommodate a population of thirty-two thousand and four hundred people, transfer methods are transferred placement;(5) Flood hazard map information includes: base map information, engineering information, flood risk information, engineering information and social and economic information. The hazard map mainly includes three kinds of flood: flood avoidance transfer map, flood inundated area map and flood depth map.