Analysis of Rainwater Pipelines for Local Flooding Mitigation

Abstract

PCSWMM was used to perform hydrodynamic simulation. Effect of water level, slope and diameter of rainwater pipelines on local flooding was investigated at free discharge and submerged discharge respectively. Bernoulli equation was applied to theoretical analysis. Results showed that increase of pipe slope and diameter could improve drainage capacity of rainwater pipes at free discharge. Rising water level seriously restricted drainage capacity of rainwater pipes. However, at submerged discharge, pipe slope promoted the construction cost, but it had no effect on its drainage capacity. With the increase of diameter, drainage capacity of rainwater pipes increased. Main factors on drainage capacity of pipes were water head different between upstream and downstream, pipe diameter and roughness coefficient. Hence, it’s recommended that urban drainage system should properly control water level and increase pipe diameter at submerged discharge. The results are important implications for rainwater pipeline design to prevent local flooding.