Research And Application On Flood Dispatching Mathematical Model Of One-dimensional And Two-dimensional Combined With Flood Diversion Gates In Flood Detention Basin

Flood occurred many times in China during recent years, and it caused heavyeconomic losses and huge casualties. This paper simulates and calculates flooddispatching process in the non-structural flood control facilities-flood detention basinwith mathematical model, data on flood depth, inundated area and flood duration etc.are obtained, and these results provide strong technical support and scientific basis forthe flood control and social economic development of the flood detention basin.In this paper, one-dimensional, two-dimensional control equations are discreterespectively by three points implicit difference method and finite volume method,combined with existing topography and flood existing scheduling scheme inYondding River flood detention basin, one, two dimensional mathematical model offlood dispatching is established. In order to verify the accuracy of the model, use1956data of flood to do simulation and parameter adjustment. The main parameters ofmodel after commissioning are determined, the model is applied for Beijing’s newairport assessment of flood. The results show that the construction of Beijing’s newairport has little effect on the Yongding River flood detention basin control floodeffects. According to the results, the flood diversion stage and control flow ofSifaxinzhuang flood diversion gate are proposed. Through analyzing the influencingfactors on water lever and flow of Qujiadian sluice, holds that the total amount ofwater inflow flood and Long River maximum flow are the most important factors. Onthe condition of Beijing new airport long-term construction, using the D&M formulacalculates flood excepted loss, on the basis of depth distribution to divide disastersituation, flood risk map inYondding River flood detention basin is drawn.The mathematical model generates mesh and calculates independently forone-dimensional river and two-dimensional detention basin. Calculating the riverindependently when flow is smaller and using one-dimensional and two-dimensionalcombined mathematical model to calculate when flow is larger. One-dimensional andtwo-dimensional combined mathematical model think the outflow from river asboundary flux of two-dimensional model, the magnitude and direction of weir flowdetermined by water lever difference of one-dimensional and two-dimensional model,alternating iterative calculate the model to achieve coupling of one-dimensional andtwo-dimensional model. The water lever, flow and sequence as conditions to controlthe opening of flood diversion gates, realizing the program for flood dispatching inflood detention basin. Proposing a correction method for the D&M empirical formula in the calculation for loss of life in flood, by analyzing the flood risk coefficient showthat the revised one do better in reflecting the relationship between flood riskcharacteristics and warning time.