The Study on Flood Reduction and Securing Instreamflow by applying Decentralized Rainwater Retention Facilities for Chunggyechun in Seoul of Korea

Abstract:

Recently abnormal climate phenomena and urbanization recently causes the changes of the hydrological environment.

To restore the hydrological cycle in urban area some fundamental solutions such as decentralized rainwater management system and Low Impact Development (LID) techniques may be choosed.

In this study, SWMM 5 was used to analyze the effects of decentralized stormwater retention for preventing the urban flood and securing the instreamflow.

The Chunggyechun stream watershed(21.29㎢) which is located in Seoul city(Korea) and fully developed as urban area was selected as the study watershed, and the runoff characteristics of urban stream with various methods of LID techniques (Permeable pavement, small rainwater storage tank, large rainwater storage tank) were analyzed.

By the simulation results, the permeability of pavement materials and detention storage at the surface soil layer make high effect to the flood discharge, and the initial rainfall retention at the rainwater storage tank effected to reduce the flood peak.

The peak discharge was decreased as 22% for the design precipitation.

Moreover the instreamflow was increased as 55% by using adequate LID techniques

These kind of data could be used as the basis data for designing urban flood prevention facilities, urban regeneration planning in the view of the integrated watershed management.