Transformation Strategy Based On Low-impact Development Model Of Urban Drainage Systems

This paper, based on low-impact development (LID) model to build urbandrainage system transformation technology system to address the transformation ofthe traditional mode of urban drainage systems problems to reduce soil erosion andurban waterlogging, reduce the load on urban drainage and water treatment systemsto reduce water pollution, recharge groundwater, land subsidence and a seriesalleviate the problems arising from urbanization.This thesis is mainly to get the following conclusions:(1) The Status of the drainage system and the transformation of traditionalurban drainage systems technology, draw traditional urban drainage systemtransformation problems include road excavation, the impact of traffic; new pipelinesand pipeline status quo is not good convergence; destroy other pipelines, pipelineelevation conflict; capital investment, long cycle.(2) the establishment of a reservoir by the runoff, biological retention,infiltration and filtration system consisting of four low-impact development modetransformation of the drainage system of technical measures. Which include greenroof runoff reservoir system technology, sunken green space, rain barrels, cisterns;bioretention system includes Asakusa ditch; infiltration systems include permeablepavement, infiltration drainage; filtration system includes rain gardens, vegetativefilter strip.(3) Select a low-impact development measures in the green roof, Asakusaditch, permeable pavement, rain gardens for runoff reduction of pollutant reductioncalculation is described, according to the statistics of this literature several measureson runoff pollution removal of all kinds of pollution substances.(4) Based on the drainage system transformation technology system oflow-impact development model to Huichang County district, for example drainagesystem reform designed to achieve a significant reduction in cell transformation afterrunoff goals through these technical measures. Transformation needed to achieve thetarget of rainwater retention volume1392m3. Green roofs where rainwater retention volume287m3; infiltrate stormwater retention amount pavement46m3; rooftoprainwater harvesting water468m3; sunken green stagnant water387m3; rain gardensstagnant water204m3.(5) the effect of reducing the volume of rainwater residential district to evaluatethe status quo pipeline P=1,=0.85, storm intensity formula q=3173(1+0.56lgP)/(t+10), runoff coefficient of0.4after LID measures by calculation, obtained withoutchanging the original case drain line can make the drainage capacity of the existingsewer lines in the region to achieve more than once in five years.