Forest-based Disaster Risk Reduction
- Forestry and Forest Products Research Institute, Japan

Increased disaster risk due to uncontrolled clearing of forests

The increased risk of disasters due to climate change is particularly pronounced in developing countries. Limited adaptive capacity and high vulnerability are among the factors that explain high disaster risks in developing countries. Accordingly, the process of development is expected to result in higher capacity and resilience in such countries. However, it is not always the case that the development process leads to higher adaptive capacity and resilience in developing countries. In many cases, the development process can even lead to a higher risk of disaster.

This situation can be seen in development processes in mountainous areas. Mountainous areas, both lower layer and highlands, are usually covered by forests. Any increase in population brings with it higher demand for food supply and agricultural productions, which results in these forests being converted into agricultural land. According to FAO, around 70% of deforestation is caused by agriculture. A recent study reports on the continuing deforestation in Southeast Asia, the location of half of the world's tropical mountain forests, and the area of deforestation is expanding from lower mountainous areas to highlands (Feng et al., 2021). It is well known that the loss of forests in mountainous areas causes various negative impacts. One such impact is the loss of extensive root systems of trees in mountains which raises the risk of soil erosion and landslides. While it is certainly necessary to cultivate land due to the increasing population and food demands, it is vital to maintain proper and sustainable land management. Without this, the expansion of agricultural fields may trigger uncontrolled clearing of forests, resulting in loss of biodiversity and high disaster risks.

Scientific evaluation of the DRR function of forests

The Forestry and Forest Products Research Institute (FFPRI) is trying to tackle this issue through its research activities based on Japanese experience and expertise. FFPRI enhances this experience and expertise to manage mountainous areas, using what are known as “Chisan” (forested hillslope conservation) technologies, and applying them to Asian developing countries. FFPRI underlines that one of the reasons for uncontrolled clearance of mountainous forests is a lack of knowledge regarding the various functions of forests. One recent project by FFPRI focuses on the disaster risk reduction (DRR) function of forests, named as Forest-based Disaster Risk Reduction (F-DRR), which aims to prevent landslides and sediment runoff through well-designed maintenance of forests, forest restoration, and land-use planning based upon the GIS data of mountainous areas.

The first step to realize F-DRR is to explain the DRR function of forests. However, this cannot be fully explained scientifically, and thus is not yet fully appreciated in the policy context. FFPRI tries to fill this gap. A study by Murakami and Yasuda discussed the relationship between the locations of landslides and rainfall distribution using data from the 2017 torrential rains in northern Kyushu as a case study. This study implies that it is possible to reduce disaster risk by avoiding the use of areas with high disaster risks. According to a study by Saito et. al, there is an increased risk of landslides due to rainfall in clear-cut areas of mountains. These studies empirically identify the risk of landslides in mountainous areas and show that risk can be reduced through forest conservation.

Turning F-DRR research into concrete action

Providing an explanation of these scientific findings will not be enough to ensure that the concept of F-DRR is actually applied in developing countries. In order to implement F-DRR in Asian countries, it is necessary to properly understand local context. To this end, FFPRI is currently working on risk mapping of landslides and sediment runoff using GIS technology. Furthermore, “Chisan” technologies need to be tailored for specific local contexts. Private companies have key technologies that are useful for landslide countermeasures and forest conservancy projects. Therefore, FFPRI is trying to facilitate private sector involvement. One approach is to provide the necessary information. FFPRI is preparing country reports to outline the status of disaster risks in mountainous areas of Asian countries. These reports are expected to serve as a source of information for private companies to promote F-DRR projects in various countries using their own technologies. In sum, FFPRI does not just conduct scientific studies on F-DRR, but it also tries to facilitate implementation of such research, leading to concrete action.

There are other points that are drawn from FFPRI’s early experience on F-DRR. First, F-DRR, unlike gray infrastructure, requires more cautious care to maintain the function of the mountain ecosystem. As such, it is essential that local governments, people and communities understand F-DRR as an infrastructure that needs to be managed properly. Second, it is important to understand the limits of ecosystem functions. Compared to man-made structures, disaster reduction using ecosystems such as forests takes more time to be effective, and the combination of green and grey infrastructure may need to be considered depending on the specific situation. Lastly, there should be a holistic framework to provide a comprehensive evaluation of the functions of forest. DRR is just one aspect of forest’s functions; other aspects are carbon sinks or water conservation. F-DRR provides a starting point to halt uncontrolled clearing of forests. By appreciating these multiple functions, we can go beyond F-DRR to sustainable management and development in mountainous areas.

Acknowledgement
This article is indebted to an interview with representatives from the Forestry and Forest Products Research Institute (FFPRI) on 17 September 2021.