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Okazaki A.,University of Tokyo | Yeh P.J.-F.,International Center for Water Hazard and Risk Management | Yoshimura K.,University of Tokyo | Watanabe M.,University of Tokyo | And 2 more authors.
Journal of the Meteorological Society of Japan | Year: 2012

We evaluated change in flood risk under global warming using the output from the latest version of the Model for Interdisciplinary Research on Climate (MIROC5), an atmosphere-ocean general circulation model. River discharge for the 21 st century were simulated for the two Representative Concentration Pathway (RCP4.5 and RCP8.5) scenarios and converted to the Discharge Probability Index (DPI) to evaluate future flood risk. The occurrence of flood events corresponding to various DPI categories was calculated for each continental region. The results show a significant increase in the risk of massive flood incidents during the 21 st century in Asia, Africa, Oceania, and South America, with relatively large differences between the two scenarios. In contrast, both scenarios showed only slight increases in massive flood risk in North America and almost no change in Europe. For the RCP8.5 scenario in particular, the risk of massive flood occurrence will increase approximately ten times in Africa, seven times in Asia, and five times in South America by the end of the current century. Further analyses indicated that these projected flood increases will occur mainly due to the increases in the number of rainy days and the annual maximum daily precipitation, and the decrease in snowmelt in high latitudinal regions will play an important role on the unchanged risk in Europe in spite of the projected increase in precipitation. © 2012, Meteorological Society of Japan.

Vink K.,National Graduate Institute for Policy Studies | Vink K.,International Center for Water Hazard and Risk Management
Water International | Year: 2014

Vulnerable people require additional measures to ensure their water capabilities, as they have certain characteristics making them more vulnerable than others. As pointed out by recent studies, transboundary water access laws and policies do not sufficiently address the needs of vulnerable people. The prevailing legal arrangements often only address extrinsic vulnerability and forgo focusing on intrinsic vulnerability, which creates the need for different transboundary water legislation. This paper shows how international treaties can address the right to certain water capabilities by considering not merely the current but also future global populations into the creation of their transboundary agreements. © 2014 International Water Resources Association.

Syamsidik,University of Syiah Kuala | Istiyanto D.C.,International Center for Water Hazard and Risk Management
Journal of Earthquake and Tsunami | Year: 2013

The challenge of protecting communities in tsunami-prone populated small islands is difficult to meet. Likewise, the islands are often found with a lack of disaster mitigation infrastructure. A tsunami that occurred around the Mentawai Islands of Indonesia on October 25, 2010, causing around 500 dead, is the inspiration for this paper. This study was aimed at elaborating practices in protecting communities of small islands from tsunamis by incorporating information about the estimated time of arrival of a tsunami into the islands mitigation measures. A field survey to obtain the impacts of the tsunami on the number of casualties and damages was conducted in February 2011 around the Mentawai Islands. In the survey, a set of questionnaires were distributed in the Mentawai Islands to investigate the small island residents' responses just after the shock from the tsunami waves. This study was also followed by numerical simulations to obtain tsunami wave Estimated Time of Arrival (ETA) for the Mentawai islands. Numerical simulations were conducted using Delft3D software coupled with Tsunami toolkit. This research found that the ETAs for the Mentawai Islands range between 9-20 min. With the existing tsunami early warning system in Indonesia, the ETAs are quite short. Comparing the Simulated ETAs to the findings from the Mentawai Islands tsunami survey led to the recommendation that the best way to increase the community's preparedness for a tsunami would be by managing village-based spatial planning. Such spatial planning may include relocating the residents far away from the coastal area. This would enable the community to have more time to evacuate should a tsunami threat occur. © 2013 World Scientific Publishing Company.

Pokhrel Y.N.,Rutgers University | Fan Y.,Rutgers University | Miguez-Macho G.,University of Santiago de Compostela | Yeh P.J.-F.,International Center for Water Hazard and Risk Management | Han S.-C.,NASA
Journal of Geophysical Research: Atmospheres | Year: 2013

We explore the mechanisms whereby groundwater influences terrestrial water storage (TWS) in the Amazon using GRACE observations and two contrasting versions of the LEAF-Hydro-Flood hydrological model: one with and the other without an interactive groundwater. We find that, first, where the water table is shallow as in northwestern Amazonia and floodplains elsewhere, subsurface stores (vadose zone and groundwater) are nearly saturated year-round, hence river and flooding dominate TWS variation; where the water table is deep as in southeastern Amazonia, the large subsurface storage capacity holds the infiltrated water longer before releasing it to streams, hence the subsurface storage dominates TWS variation. Second, over the whole Amazon, the subsurface water contribution far exceeds surface water contribution to total TWS variations. Based on LEAF-Hydro-Flood simulations, 71% of TWS change is from subsurface water, 24% from flood water, and 5% from water in river channels. Third, the subsurface store includes two competing terms, soil water in the vadose zone and groundwater below the water table. As the water table rises, the length of vadose zone is shortened and hence the change in groundwater store is accompanied by an opposite change in soil water store resulting in their opposite phase and contributions to total TWS. We conclude that the inclusion of a prognostic groundwater store and its interactions with the vadose zone, rivers, and floodplains in hydrological simulations enhances seasonal amplitudes and delays seasonal peaks of TWS anomaly, leading to an improved agreement with GRACE observations. ©2013. American Geophysical Union. All Rights Reserved.

Vink K.,National Graduate Institute for Policy Studies | Takeuchi K.,International Center for Water Hazard and Risk Management
International Journal of Disaster Risk Reduction | Year: 2013

This paper focuses on measures taken for vulnerable people in Disaster Risk Management (DRM) laws in Japan, the Netherlands and the United States. As DRM laws were found to lack a definition of vulnerable people, an original working definition of vulnerable people in a community was defined.DRM laws and policies with a focus on flood disasters in Japan and the USA cover some groups of potentially vulnerable people who are supported during various phases of disaster management, such as elderly, children and people with disabilities. The basic disaster law in the Netherlands mentions 'not self-reliant people' during the response phase, and leaves further details to the regional safety plans. All countries lack clearly defined characteristics in the laws themselves as to who may be categorized among the various groups of potentially vulnerable people. Furthermore, there is little to no anticipation of expected increases in the amounts of vulnerable people.The support for vulnerable people in DRM laws has not been quantified on a global scale, even though the Hyogo Framework for Action called for the development of measurement tools in 2005. Further research should aim at developing tools with which to quantify the support of vulnerable people in DRM laws. © 2013 Elsevier Ltd.

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