**4. Conclusion**

The present work highlights a number of subjects in the arena of flood risk management that deserve further in-depth research, as summarized below.

In terms of flood hazard identification, flood peak timing and multipeak hydrographs should be given more attention.

Due to the existence of various definitions and interpretations of vulnerability, there is a need to combine or group some of the notions, if the integration of all is impossible, for the sake of a better and deeper understanding of what really constitutes vulnerability. Following this line of thinking, a new two-layer framework of vulnerability is proposed, integrating existing concepts to a certain extent. This new framework may help develop new approaches to vulnerability reduction, with new concepts such as flood sharing.

This new framework also suggests that inundation duration should be included in the analysis of exposure.

Eco-DRR is an emerging approach to achieving both flood risk management and environmental conservation and may contribute to local economies as well. However, more cases of Eco-DRR across the world should be collected and analyzed from various angles in order to quantify its effectiveness and promote best practice. In Japan, Eco-DRR is advanced in terms of the legal framework supporting it, but there is great uncertainty in terms of its performance. Innovation is indispensable in reaching a new stage of flood risk management.

**15**

**Author details**

Guangwei Huang

provided the original work is properly cited.

\*Address all correspondence to: huang@genv.sophia.ac.jp

*New Frontiers in Flood Risk Management DOI: http://dx.doi.org/10.5772/intechopen.81925*

The authors declare no conflict of interest.

This work was supported by Sophia Research Branding Project 2016.

**Acknowledgements**

**Conflict of interest**

© 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

Graduate School of Global Environmental Studies, Sophia University, Tokyo, Japan
