Optimization Of Urban Storm Water Drainage System Based On Low Impact Development

With the continuous expansion of the urban scale, the hydrology balance wasdestroyed, coupled with frequent storms in recent years, the urban waterloggingdisasters occur frequently. Low-impact development plays an important role in thehydrological and ecological significance by effectively reducing the total amount ofthe runoff, reducing runoff pollutants and improving the urban environment. So it isvery important to find a way to use of low-impact development to reform the urbandrainage systems technologically, efficiently and economically.First of all, we experimentally analyzed and summarized the runoff reductionand pollutant removal performances of the three most commonly used LID methods-green roofs, permeable pavement and green depression. The impact of green roofsubstrate materials and depth on runoff quality and the pollutant removal mechanismwas specially expounded.Then the target area properties and hydrological conditions were overviewed andthe layout of target area and possibilities of applying low impact development on thearea were analyzed. On these bases, the storm system model of Info works ICM wasestablished. The influence factors on the reductions of the total runoff, peak runoffand the runoff time coefficient was analyzed by model simulation under different rainevents. After these, a comprehensive evaluation of the regional storm drainagesystems was conducted.An optimization model of low impact development the urban drainage systemswas proposed with the overall goal of the economic, hydrological and environmentalbenefits. Finally, after optimizing the reforming plan of the target area with this model,the performance of the optimized solution was re-evaluate to provide a reference forregional planning renovation projects.