Runoff Control Potential for Design Types of Low Impact Development in Small Developing Area Using XPSWMM

The increase in impervious area caused by development project has resulted in prone to water management with climate change, which can affect the water cycle, including the ecosystem. It has been pointed out as a major cause of water pollution according to nonpoint source runoff increases, as well as the cause of disasters such as floods and inundated with heavy rains. In particular, the increase in the impervious surface induces a rapid release of rainfall and brings an increase in the surface discharge by reducing the permeability of the area of the existing tree. LID techniques have been widely applied in order to recover water environment conditions prior to the development reducing the impervious area. The study on the optimum type, the number and placement of LID facilities suitable for area characteristics is being carried out, but the research for the actual design which is about the effect of runoff reduction from the combination of LID facility makes the difficulty of LID effect prediction. Consequently, this study analyzes runoff characteristics for the units and combination of LID facilities through real LID design practices, and identified the effect of runoff reduction and climate change responsiveness the for the combination of retention-Infiltration facilities as the rainfall scenario. The result was confirmed that a combination facilities has about 10% or more of the peak runoff reduction than the single one, observed more outstanding effect of runoff reduction in combination facilities higher the storage capacity of among combination facilities, particularly when the proportion of retention-Infiltration is 1:2 (1,000m3-500m2), it was possible to obtain up to 26% or more of the peak runoff reduced. When LID techniques are applied to areas similar to the present study, runoff reduction can be predictable based on the results from this research, above all the method and guidelines for optimum capacity selection of combination facilities of retention-Infiltration to achieve the targets of runoff reduction, which is used as a reference for LID design of future projects suitable for the condition and characteristics of target area.