Introducing Japanese Landslide Warning and Evacuation System to Sri Lanka: Field Survey of Social Aspect in the Arayanake Area

Abstract

AbstractThe central highland in Sri Lanka has a landslide-prone geo-hydrological condition. In addition, Sri Lanka has extreme rainfalls in two monsoon seasons, and most of the landslides occur during two monsoon seasons. Landslides in the central highland had been isolated events. However, the area has been developed for agriculture and human settlements, a series of landslides occurred in the mid-1980s. Since the topography, such as mountains with steep slopes and weather, such as high precipitation, are similar in Japan and Sri Lanka, similar landslide phenomena have been seen. One of the common landslide phenomena is rain-induced rapid and long-travelling landslides (RRLL). Landslide disaster risk reduction technologies have recently been developed in Sri Lanka, and foreign technologies have been introduced. Early warning and evacuation using a hazard map is a major system for landslide disaster risk reduction both in Japan and Sri Lanka. Japan has already developed and used the early warning and evacuation system using hazard maps. Since the system has been developed based on Japan’s socio-economic background, it is used successfully in Japan. Thus, when this Japanese technology is used in Sri Lanka, in addition to the engineers’ availability to master technologies, local people’s availability to accept the technology is also examined. In this research, the social background for introducing Japan’s early warning system in Sri Lanka is analyzed based on the field survey at Arayanake. The questionnaire survey and interview were implemented in January 2023, and there were 50 respondents. The survey showed some essential conditions to be improved for the successful warning and evacuation.