| With the continuous development of China’s economy and the acceleration of urbanization,China’s land has been overexploited,which has caused the underlying surface to be over-hardened,and the permeable green space has been dramatically reduced,destroying the city’s original natural ecological background and hydrological characteristics.It is easy to cause urban waterlogging,which causes a large loss of rainwater resources.As a part of urban construction,the construction of railway station areas has a huge impact on the normal operation of railways and people’s lives and property.In recent years,waterlogging has occurred frequently in China’s railway stations.The drainage concept of the traditional railway station area is mainly drained quickly through the form of drainage,rainwater pipes,etc.,or to the nearest municipal pipe network in a timely manner.This not only makes insufficient use of rainwater resources,but also aggravates the burden of drainage of the downstream municipal pipe network,which is extremely easy.Caused floods.Reasonable and effective use of low-impact development(LID)technology can effectively alleviate the urban rainwater contradiction.At present,the simulation of rain flood control in urban areas(such as residential areas,urban streets,etc.)based on LID technology is relatively mature,but due to the geographical location of railway stations Due to the special nature,the availability of hydrological data,and the restrictions on economic,safety,and management conditions,research on rainwater management in railway station areas is rare.Therefore,in order to promote the use of rainwater resources in railway station areas,reduce the pressure of rain and flood in railway station areas,strengthen ecological environmental protection,and improve the green level of railway construction,design economic,reasonable and efficient LID rain and flood management solutions for railway station areas.It is of great significance for the control of rainwater runoff and non-point source pollution in the railway station area.Based on low-impact development technology,this paper uses the SWMM model to conduct comprehensive research on runoff control strategies for rainwater runoff and non-point source pollution in railway station areas.Design and simulate single and combined LID facilities in the study area,and compare and analyze the ability of different schemes to improve rain and flood management in the study area.A comprehensive benefit evaluation system for railway station area LID measures with a core of technological economy-environment-social benefits was established,and different quantitative methods and grading standards for indicators were determined.Based on the fuzzy comprehensive evaluation theory,the optimal method of constructing the LID scheme of the railway station area based on the principle of optimal comprehensive benefits was comprehensively evaluated.First,by analyzing the actual conditions such as meteorology,hydrology,topography,land use types,etc.,based on the rainwater pipe network and design planning drawings of the research area,the drainage pipe network was generalized using the Auto CAD and HS-Data plug-ins.Water area,establish regional SWMM model.Based on the empirical values of the parameters,the water quantity and water quality parameters are calibrated and verified with the help of two measured rainfalls to ensure the accuracy of the model and provide model support for subsequent research.According to the nature of the railway station area,the type of land,etc.,four types of LID facilities suitable for the study area are selected: permeable paving,green roof,grass ditch,and biological retention ponds,and 16 different LID rainwater systems are designed in combination.Program.The SWMM model was used to simulate and compare the effects of single and combined LID schemes on rainfall runoff and pollutant load in the study area under different intensities and short-duration storms.The results show that the biological detention pond with a single measure has a better control effect on the runoff and pollution load in the study area,and the combined scheme containing the biological detention pond + permeable pavement has a better design effect.The effect of the combined scheme is better than the single scheme.The more LIDs connected in series,the better the overall effect.Based on this,the rain and flood management capabilities of different LID schemes in the study area are summarized as the basis for evaluating the benefits of pollution interception and emission reduction.From the three aspects of technical and economic benefits,environmental benefits,and social benefits,the evaluation factors that reflect the comprehensive benefits of the LID design scheme were identified,including three first-level indicators and 13 second-level indicators,forming a set of comprehensive evaluation of LID measures for railway station areas.Indicator system.Through the study of the measurement methods of each evaluation index,the quantitative calculation formulas of each evaluation index are given.Through the in-depth analysis of the existing national,industry and local standards,specifications and technical guidelines,the comprehensive benefits of the LID measures in the railway station area are determined.Classification criteria and the classification criteria for each rating.The fuzzy comprehensive evaluation method based on combined weights is used to optimize and quantitatively evaluate the individual and combined LID rain and flood management schemes in the study area.The results show that the comprehensive benefit evaluation result under the traditional development model is very poor,which is grade Ⅴ,so it is necessary to carry out sponge urbanization transformation in the study area.The comprehensive efficiency of schemes S12,S13,and S14 all reached the second-class superior level,and the comprehensive benefit score of scheme S12 was the highest.Therefore,the combination of LID measures of scheme S12 was selected in this paper to transform the second phase of Lanzhou West Railway Station and Plaza At the same time,it has guidance and practical significance for the LID construction of the third phase of the square and similar sites that are still in the planning and design stage. |
