Applying the 3-layer approach to urban flood management
Purpose – The purpose of this paper is to find the possibility of extending the capacity of urban drainage in highly urbanized cities with limited available space for flood management, while the anticipated increase in extreme rainfall is expected to raise the demand for higher capacity of water drainage or storage systems. Design/methodology/approach – The concept of the three-layer approach is introduced to identify the crucial factors which had impacted the historical change of natural water system. These factors can further help identifying potential spaces for new designs of flood management based on the spatial context of local history. Findings – In Pingtung case, a roadway surface drainage design is found as a complementary strategy by this method, which could effectively and practically extend the capacity of urban drainage without the need for requisitioning private lands or rearranging the complicated underground pipe and cable systems. Research limitations/implications – This is an initial exploration from the perspective of urbanism to respond to hydrological problems under the impact of extreme rainfall. The more precise hydrologic simulation need to be further established. Practical implications – This concept could be applied in delta cities to improve urban drainage by three steps: first, clarify the flooding problems; second, identify the available space; third, redesign hydrologic instrument with a multi-use of urban space. Originality/value – This research provides hydrologists and urban planners with a practical collaboration base for the issues of extreme storm events.