An Empirical Study on Visualization of Efficiency of Disaster Warnings to Citizens: ―A Social Experiment of Warning Dissemination by Loudspeakers and SMS at Rural Mountainous Areas in Thailand―

: One of the most highlighted benefits of using GIS in the field of disaster risk reduction is to visualize the disaster-related information. It helps citizens to understand the post-disaster situation, disaster prone areas, and so forth for better decision making and countermeasure actions. However, GIS has not been utilized yet to visualize efficiency of disaster warning dissemination. We therefore, conducted an experiment to issue warning messages through various media, such as loudspeakers and SMS, at rural mountainous areas in Thailand, and visualized the warning messages distribution. As a result, it was clarified that although the media has both positive and negative characteristics, the each medium works as complementary manner to another for efficient warning. The result was presented visually as maps so that they would contribute for further discussion of warning dissemination strategy and for heightening of citizens ’ disaster awareness.