In recent years, the world has been experiencing frequent and unexpected natural disasters such as heavy rainfall, storm surges, storm waves due to climate change, and tsunamis associated with huge earthquakes. The 2019 Intergovernmental Panel on Climate Change (IPCC) Special Report on the Ocean and Cryosphere (SROCC) and the 2021 Sixth Assessment Report (AR6), in particular Sea-level rise projections under the high-end greenhouse gas emissions scenario (SSP585) have been revised upward to the upper side to 1.1 m at the end of the century, and future changes in waves and storm surges are reported to have serious impacts on coastal vulnerability. Under these circumstances, it is feared that high waves and storm surges and tsunamis will become a serious challenge in Southeast Asian and South Pacific countries.
Coastal areas are not only the economic base for industry, fisheries, and tourism, but also the foundation for housing, recreation, and other aspects of life, taking advantage of the flat land and rich natural environment. Therefore, it is an internationally important issue to resolve the trade-off between a comfortable society in normal times and a safe and secure society in emergencies against possible natural disasters in the future. Therefore, there is an urgent necessity to establish harmonic coastal defense technologies that aim at the best mix of assessing the intensity of coastal disasters such as storm waves, storm surges, sea-level rise, and tsunamis, reducing vulnerability by constructing defense systems, and maintaining and creating environmental resources in harmony with nature and with local characteristics.


Current situation in Indonesia/インドネシアの沿岸防災に関する現状の課題

Indonesia is a coastal and maritime country consisting of 13,466 islands and has the world’s second longest coastline of approximately 54,000 km. However, protection against natural disasters is insufficient, and in addition to long-term and widespread coastal erosion, recent climate change has increased the vulnerability of coastal areas due to frequent flooding and predicted sea level rise.
In this context, there is a strong need to preserve coastal areas in a way that balances disaster prevention, the environment, and the economy. One example is the measures taken against the earthquake and tsunami in Sulawesi that occurred in 2018. Here, the development of the backlands has been promoted in consideration of the balance between residents who do not want too high embankments and disaster prevention functions such as breakwaters, and it is expected that this kind of initiative will be deployed throughout Indonesia. Coastal erosion caused by high waves is also a major problem in the preservation of coastal areas. In particular, coastal erosion is severe in Sumatra and Bali, where 20% of the coastline is being eroded. In Bali, JICA’s “Bali Coastal Conservation Project” is underway in two phases. In the evaluation of the project in Phase 1, the need for regular monitoring and adaptive management was identified as an issue. Furthermore, the decrease of mangrove forests due to logging, etc. has become more pronounced, leading to further degradation of the disaster mitigation function. Therefore, scientific support for monitoring, erosion mechanism elucidation, long-term forecasting, and erosion countermeasures is considered essential.


Targets of project/本研究プロジェクトの概要および目標

In this project, we will develop a method to improve the defense function of coastal areas based on the latest scientific evidence such as monitoring, modeling, and green infrastructure, and to transfer the monitoring network and analysis technology using the latest technology to improve the defense function of coastal areas in harmony with disaster prevention, environment, and economy. The objective is to realize social implementation of creation in 5 to 10 years. As social implementation based on this scientific data, we will attempt to build a platform for consensus building, and these results will contribute to the realization of a “super-smart society,” which is the fusion of cyber and physical space, as a fundamental technology in Japan’s 5th Science and Technology Basic Plan.

In order to realize the objectives, this project aims to develop the following three research projects: 1) transfer of wave observation technology in coastal areas of Indonesia, development of monitoring technology for sandy beaches and mangrove forests; 2) construction of multi-hazard evaluation methods for waves, tsunamis and floods; 3) disaster mitigation functions by mangroves and sandy beaches against waves, tsunamis, and floods. 4) Establishment of environmental education and eco-tourism to promote maintenance and management of green infrastructure, systematization of evacuation planning and education for backlands areas, and consensus building methods based on these four issues. Build an integrated platform for coastal defense technologies.

The main sites are Bali, Ambon, and the east coast of Kalimantan.