Under The Urban Rainwater Control Technology System Research Based On Low-impact Development Pattern

Paper based on low-impact development pattern Establishment the urban rainwater controltechnology system research.Thus to achieve the control of urban soil erosion and water logging, reducethe load of urban drainage and water treatment systems, reduce water pollution, recharge groundwater, andalleviate a series of problems such as ground subsidence caused by urbanization.The main work and achievements of the paper include the following aspects:(1) The paper analysis of drainage status and traditional urban rainwater drainage systems technologyprinciple, obtain the reasons of waterlogging in rain removal system include four aspects: old urbanrainwater design concept, low design standards and lag of construction, imperfect government regulation,and lack of capital investment.(2) Combined with the principle of the best management practices, low-impact development patternand green rainwater infrastructure, the paper put forward modern urban rainwater control technologysystem based on low-impact development pattern according to the requirements and characteristics ofChina’s urban development. Urban rainwater control system realizes a variety of objectives such as runoffvolume reduction, pollution control, peak flow reduction, extending the convergence time, the use ofrainwater harvesting and rainwater transfer of emissions. depending on the application object, urbanrainwater control system can be divided into construction and residential rainwater systems, roadsrainwater systems, green and open space rainwater systems, etc.(3) Establish the LID mode rainwater control and using technical measures consist of rainwaterbio-retention facilities system, rainwater infiltration facilities system and rainwater storage facilities system.Bio-retention system includes green roof technology and the concave green technology; rainwaterinfiltration system includes ground penetration, infiltration trench, infiltration wells and infiltration pool(pond); rainwater storage system includes roof water storage system, ground reservoirs, and undergroundgravel water storage.(4) Under the urban rainwater control technology system based on low-impact development pattern,taking Yangling “Jinyi International City” residential area for example, conduct rainwater control andusing design, to achieve the residential community runoff after development is not greater than the goalbefore development through the rainwater control technical measures. A total retention of rainwateramount is required985m~3to achieve the control target. Green roofs rainwater retention amount is163m~3; penetration pavement rainwater retention amount is70m~3; rooftop rainwater collection amount is318m~3;concave green water holding capacity is366m~3; rain gardens water holding capacity is68m~3.(5)Yangling “Jinyi International City” residential area rainwater volume reduction effect evaluation,select P=1，=0.65, storm intensity formula with reference to Xi’an, the runoff coefficient is selected0.3after LID measures, the paper obtains the result by calculating that make drainage capacity of the existingregional municipal rainwater pipeline to five years or more without changing the original municipalpipeline case.