Vegetation bioshields for tsunami mitigation: review of effectiveness, limitations, construction, and sustainable management |
| |
Authors: | Norio Tanaka |
| |
Institution: | (1) Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama Saitama, 338-8570, Japan |
| |
Abstract: | Coastal vegetation has been widely recognized as a natural method to reduce the energy of tsunami waves. However, a vegetation
barrier cannot completely stop a tsunami, and its effectiveness depends on the magnitude of the tsunami as well as the structure
of the vegetation. For coastal rehabilitation, optimal planning of natural coastal systems, and their maintenance, we need
to quantitatively elucidate the capacity of vegetation to reduce the energy of tsunami waves. The limitations of coastal forests
in relation to the magnitude of a tsunami and the maintenance of forests as natural disaster buffer zones have to be understood
correctly for effective coastal vegetation planning. Demerits of coastal forests have also been revealed: for example, an
open gap in a forest (i.e., a road, river, difference in elevation, etc.) can channel and amplify a strong current by forcing
it into the gap. Floating debris from broken trees also can damage surrounding buildings and hurt people. However, many studies
have revealed that these demerits can be overcome with proper planning and management of mangroves and coastal forests, and
that coastal vegetation has a significant potential to mitigate damage in constructed areas and save human lives by acting
as buffer zones during extreme natural events. However, mangrove forests have been damaged by anthropogenic activities (i.e.,
tourism, shrimp farming, and industrial development), making coastal areas increasingly vulnerable to tsunamis and other natural
disasters. The effectiveness of vegetation also changes with the age and structure of the forest. This highlights the fact
that proper planning and management of vegetation are required to maintain the tsunami buffering function of coastal forests.
Although many government and nongovernmental organizations have implemented coastal vegetation projects, many of them have
been unsuccessful due to a lack of proper maintenance. A pilot project in Matara City, Sri Lanka, revealed that participation
and support from local authorities and communities is essential to make the planting projects successful. An integrated coastal
vegetation management system that includes utilization of the materials produced by the forest and a community participation
and awareness program are proposed to achieve a sustainable and long-lasting vegetation bioshield. |
| |
Keywords: | Tsunami protection Buffer zone Forest structures Participation and support of local authorities Integrated management system |
本文献已被 SpringerLink 等数据库收录! |
|