Research On Urban Park Rainwater Utilization Technology Based On Low Impact Development(LID)Concept

In the rapid progress of urbanization,the "rainwater" problem of urban construction not only restricts the development of the city,but also brings great inconvenience to the citizens,and even threatens the safety of life.As an objective subject of urban water consumption,urban green space needs to be irrigated every year to meet the growth needs of green space.From the problems of urban rainwater,waste of water in the park and the failure of urban rainwater resources to be effectively utilized,the concept and measures of low impact development are introduced into the planning and design of urban parks to provide an effective way to solve the problem of urban rainwater.This paper makes a systematic analysis of the theory and practice of rainwater collection and utilization in urban parks at home and abroad,and summarizes the function,application scope,research progress,conditions,advantages and disadvantages of urban parks and the future development of the urban parks with the combination of pavement,green space,water landscape and building.It provides a reliable theoretical basis for the study of this paper.Secondly,three kinds of LID technology suitable for the study area are selected,which are green roofs,shallow gully and permeable paving,and the SWMMH model of the research area is constructed,and the sensitivity analysis of some parameters involved in the model is carried out,and the peak flow rate of the outlet of the area is simulated according to the model,and the peak flow rate of the water outlet of the area is simulated.The peak time and runoff coefficient are used to evaluate the application effect of LID technology in the study area.?the insensitivity of sub catchment area is the most sensitive model parameter of runoff coefficient and peak flow volume,that is,the setting of the parameter has a great influence on the simulation results.When model parameters are set,priority should be given to identifying and focusing the parameters.?Under different rainfall recurrence periods,the peak flow and runoff coefficient of LID in the study area were reduced compared with those without LID technology.?under different rainfall recurrence periods,the peak time of using LID technology in the study area is lagging behind that of the LID peak.?Under different rainfall recurrence periods,the LID technology reduces the peak discharge and runoff coefficient and decreases with the increase of rainfall recurrence period.Based on the site conditions of the study area,a comprehensive application design scheme for green roofs,shallow fuirrows and permeable paving is carried out in the study area,which provides a reference for the practice of low impact development technology in urban parks.The construction of urban park rainwater system model provides an effective method and way for the evaluation of low impact development technology operation effect.It also provides data support for the popularization and application of low impact development technology,and provides an effective way to solve the "rainwater" problem in China.