Policy and systems of flood risk management: a comparative study between Japan and Spain

Abstract

This paper shows a comparison from the perspective of flood risk management between two regions of different countries: Tokyo Metropolis (Japan) and Catalonia (Spain). The comparison is based on flood damage data for a 30-year period (1981-2010), legislation, disaster management plans, recovering measures, and communication strategies. A total of 219 flood events and 110 deaths were recorded in Catalonia during 1981-2010, while there were 191 floods in Tokyo, during the same period, giving place to 27 deaths and missing people. In both countries, most of the deaths occurred outdoors and the majority as a consequence of imprudent behavior. Nearly 10% of flood victims in Catalonia were foreign citizens. Regarding the institutions from the state and the communities involved in flood risk management, we have found a similar structure between the two countries. In accordance with the European Floods Directive, all the Spanish regions susceptible of having floods have flood hazard maps for different return periods, including 500 years while in the case of Japan the return periods are usually shorter. Recently, flood risk maps have been built for Catalonia, but none is available in a foreign language. Although all the maps are available in Internet, in Spain it is not mandatory to distribute maps to the public neither evacuation maps in flood-prone areas. On the contrary, evacuation and hazard maps in Japan have some parts written in different languages. In both countries, flood hazard maps are not compulsorily linked to other countermeasures such as land-use regulation (the municipality has the last decision) or flood insurance. Thresholds of heavy rain warnings are similar in both countries, using rain amounts over both short and long periods. Although the Japanese method appears more sophisticated using humidity and runoff indexes, it is too complicated for people to understand it. In contrast, only Catalonia has forecast thresholds considering probability levels. On flood insurance, only Spain has governmental aid to the flood insurance system. The level of flood risk perception is low among the population in both countries, and social communication for flood risk is insufficient, mainly in Catalonia. Thus, it is very important that individuals recognize the flood risk in the area to reduce the number of victims.