A Flood Risk Analysis On A River Of Jilin Province

There are many branches for the river in the research of this paper,the river system within the river basin is developed and the undulating change of terrain is large for which flood is frequently induced during the stormy days which brings huge damage to the life and property of the local people.With the comprehensive consideration for the propagation characteristics of rivers for the flood in the research,the structural shape of the embankment on the two banks,the topographical features and spatial scales of the protection zone against the flood etc.this paper is applied with the model method to conduct the analysis on the flood risk for the rivers in the research and judge the influence of the simulation for the dike breaching on the protection zone against flood.On the base of this data achievement,the flood risk diagram is drawn.The main content and achievement of this paper are as follows:1)Collect the basic data such as the hydrology,basic geographic information,social economy and historical flood disaster etc.of the study region,conduct the process,hydrological analysis and calculation for the basic data.2)Utilize Mike 11 to establish the one-dimensional non-constant flow dynamic model and simulate the process of flood evolution in the rivers of the research;utilize Mike 21 to establish the two-dimensional non-constant flow dynamic model and simulate the process of evolution for the entry of flood into the inundated area.Couple the one-dimensional,two-dimensional non-constant flow dynamic model through Mike flood.As the important model parameter,roughness coefficient shall be selected for the rating and verification of the model,the result of rating and verification shall meet the “guidelines for the preparation of flood risk diagram”,indicating the model has higher precision which may be applied for the analysis on the regional flood.3 Utilize the established model to conduct the calculation of flood analysis on the proposed burst mouth at Changsheng Village and the overflow of flood that exceeds the standard to obtain the achievements of flood evolution for the occurrence of established flood combination and extract the depth of water for the submergence of the flood and the arrival time of the flood.4)According to the scope of flood submergence and the physical data of investigation,obtain the influence of different water depths on the flood and the loss for the disaster with the application of the loss evaluation software released by the country through the establishment of loss ratio.For the standard of one flood with the occurrence of every 50 years in the main river of the research,the proposal for the burst mouth at Changsheng Village shows the regional area of submergence as 10.32km2,the population of submergence is 32.3 thousand,the cultivated area of submergence is 5.93km2,the total economic loss is 456.9672 million RMB.For the flood with the occurrence of every 100 years,the proposal for the burst mouth at Changsheng Village shows the regional area of submergence is 12.98km2,the population of submergence is 39.7 thousand,the cultivated area of submergence is 7.89km2,the total economic loss is 633.4344 million RMB.For the flood with the occurrence of every 100 years,the proposal of embankment for the submergence of flood shows the regional area of submergence is 44.07km2,the population of submergence is 31.9 thousand,the cultivated area of submergence is 30.73km2 and the total economic loss is 1534.181 million RMB.5)According to the analysis achievements of flood risks,based on the proposal of retreat and migration,with the integration of the population quantity and scope for the avoidance of risk and migration,reasonably divide into units,coordinate and arrange the site for settlement,scientifically analyze the route for the avoidance of risk and migration.For flood with the occurrence of every 100 years,the proposal for the burst mouth at Changsheng Village plans the migration of 10449 people.6)On the base of the basic geographical base map,utilize the drawing software provided by the project team for the preparation of the flood risk nationwide,overlay the distribution layers of water conservancy project,the socio-economic layers and the flood analysis and calculation result,draw the flood risk diagram and the diagram for the avoidance of risk and migration.