| Flood and waterlogging disasters are one of the main natural disasters in China,threatening the safety of people’s lives and property,and constraining the development of the economy and society.With the advancement of China’s urbanization process,more and more cities are developing,and the population industry is gradually concentrated.And with the development of urbanization,various links of urban rainwater and flood processes have also undergone changes.Affected by the terrain and terrain of mountainous areas,small towns in mountainous areas are facing more complex and ever-changing threats from flood disasters.Therefore,it is particularly necessary to study the simulation and analysis of flood disasters in small towns in mountainous areas.This study takes Liubu Town in Jinan City as an example and uses the GRMS.Based on the characteristics of the research area,data is collected to establish a flood disaster simulation model for small towns in mountainous areas coupled with river channels,pipeline networks,and surface.The rain and flood process in the research area is simulated,and the inundation caused by flood disasters is analyzed.From a holistic perspective,rationality and economy are comprehensively considered based on the weak links of its drainage system,Effective governance measures have been formulated.The main research content of this article is as follows:(1)Establish a one-dimensional river model,urban runoff and pipe network model,and two-dimensional surface model within the research area.Couple the pipe network model with the surface model,river channel model with the surface model,pipe network model with the river channel model through inspection of well nodes,riverbank lines,and drainage outlets,and construct a river channel pipe network surface coupling model.By using measured rainfall data and flood disaster investigation data,the model was calibrated and validated.After calibration,the maximum relative error of the model was less than 10%.The model has certain reliability and can be used to simulate the flood disaster process in the research area.(2)Establish a one-dimensional river model,urban runoff and pipe network model,and two-dimensional surface model within the research area.Couple the pipe network model with the surface model,river channel model with the surface model,pipe network model with the river channel model through inspection of well nodes,riverbank lines,and drainage outlets,and construct a river channel pipe network surface coupling model.By using measured rainfall data and flood disaster investigation data,the model was calibrated and validated.After calibration,the maximum relative error of the model was less than 10%.The model has certain reliability and can be used to simulate the flood disaster process in the research area.(3)Using a coupled model,simulate the process of flood disasters in five frequency scenarios in the study area.Analyze the inundation depth and flow velocity of the study area when flood disasters occur at various frequencies.The maximum water depths for a 100 year return period,a 50 year return period,a 20 year return period,a 10 year return period,and a 5year return period are 2.21 m,2.07 m,1.38 m,0.89 m,and 0.74 m,respectively.The maximum water depths are 3.31m/s,2.85m/s,2.60m/s,0.79m/s,and 0.64m/s,respectively.According to relevant regulations and standards,combined with the submerged depth and submerged flow velocity,risk classification is carried out for each location in the research area.(4)According to the model simulation results and weak link analysis,a combination plan for flood disaster management is proposed,and the effect of the treatment scheme is verified by relying on the coupled model of river channel-pipe network and land surface,and the flood disaster management scheme that meets the governance requirements is found out through anyway.It mainly adopts the measures of river dredging,dike rectification and drainage pipe diameter widening.After treatment,when the study area suffered heavy rainfall once in 20 years,the pipe network and river did not overflow,and there was no obvious flooding phenomenon in the town. |
