Social lives of tsunami walls in Japan: Concrete culture, social innovation and coastal communities

Abstract

This paper is the beginning of a reflection on the ways in which the Great East Japan Disaster (2011) might have changed people’s perception of seawalls and hard coastal defence in Japan. A highly developed society that is prone to frequent large tsunamis and storm surges, Japan’s spending on physical coastal defence has few equals around the world. The development of sea defence became a priority during the 1960-70s when coastal engineers and related agencies developed national standards. One of the chief strategies has been the edification of seawalls and other hard structures, which today surround more than 40% of Japan’s coastlines. This technological advancement might have created a general sentiment of security and trust in the ability of these coastal structures to protect coastal communities, their infrastructures and their nuclear plants. On March 11 2011, however, this general sense of safety was hardly shaken by a M9 earthquake and its ensuing tsunami taking away the lives of over 15,000 individuals and causing a material loss of over 210 billion dollars. If experts had anticipated such a large earthquake, the height of the tsunami waves and the extent of the damaged suffered along the coast of northeast Japan surpassed even the most pessimistic predictions. Reflecting on the impact of this tragedy, this paper is a first attempt to appreciate whether Japanese people’s perception of and approaches to seawalls and other coastal defences might have changed as a result. The first part of this paper provides a brief analytical overview of the culture of sea defence and its socio-economic significance in Japanese society. The second part examines more specifically the ways in which seawalls might have influenced people’s behaviour during the events of the Great East Japan Earthquake, including their creating a false-sense of security. Finally, the third part focuses on relatively innovative approaches to coastal defence in post-disaster Japan, with a particular focus on a national project known as the Great Forest Wall. Rather than its engineering efficacy, the interest in this project lies in the ways in which the project might inform us of changing people relationships and ideas with coastal defence.

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