9:30 AM - 9:45 AM
[G01-03] Creation and Evaluation of 3D Hazard Maps Using 3DCG
Keywords:hazard map, 3DCG, Inundation Forecast
1. Introduction
In recent years, wind and flood disasters have continued to occur on a large scale in the Japanese archipelago. As the damage caused by torrential rains increases, flood hazard maps are being developed in each region. In particular, the areas affected by the July 2008 torrential rains overlapped with the hazard areas on the hazard maps, and a proper understanding of the hazard maps will help minimize the damage caused by disasters. However, according to a survey conducted in January 2019 by the Disaster Prevention Diorama Promotion Network (1,772 people surveyed), only 17.7% of respondents answered that they understand the disaster risks around them from hazard maps. Of those who have seen hazard maps, 22.2% answered that it is difficult to understand how much risk there is, indicating that it is not easy to understand the extent of inundation.
Topography has a significant impact on flooding, and is an important data source for creating hazard maps. However, it is difficult to understand the large topographic features even in the areas where people usually live. In addition, topographic maps published by the Geospatial Information Authority of Japan (GSI) include buildings and other structures, making it sometimes difficult to decipher contour lines, especially in urban areas.
Therefore, in order to promote understanding of flood hazard maps, this study aimed to develop 3DCG teaching materials that facilitate intuitive understanding of topographical features and to verify their effectiveness.
2. Creation of teaching materials
The created teaching materials can be viewed on the web. The 3DCG data of the terrain was obtained from the Geospatial Information Authority of Japan (GSI) map website. Then, 3DCG of arrows and letters were added using Blender. The created files were uploaded to the web-based platform Sketchfab and converted to USDZ format. The converted files were downloaded to iPads, which can display the created teaching materials in AR and normal display.
3. class practice and evaluation
We conducted a class practice using this teaching material for 240 second-year male junior high school students in the Tokyo metropolitan area. In the classroom practice, the inundation zones were predicted for the Shibuya and Komaba districts, using the plane topographic maps, 3DCG 3D topographic maps, and 3DCG 3D hazard maps of the respective areas. In order to separate the effect of the teaching materials from the effect of the difference in difficulty between the Shibuya and Komaba districts, two groups were set up: Group A, in which the Shibuya district was studied first and then the Komaba district was studied, and Group B, in which the Komaba district was studied first and then the Shibuya district was studied.
The evaluation of the created teaching materials was based on the results of the inundation zone prediction (comprehension survey) conducted during the class and the students' awareness survey conducted after the class. The results of the comprehension survey showed that, as an overall trend, the percentage of correct answers for inundation areas along plateaus and valleys tended to be higher with 3DCG 3D topographic maps than with planar topographic maps. On the other hand, for depressions on the plateau, the percentage of correct answers tended to be lower for the 3DCG 3D topographic maps than for the planar topographic maps.
In recent years, wind and flood disasters have continued to occur on a large scale in the Japanese archipelago. As the damage caused by torrential rains increases, flood hazard maps are being developed in each region. In particular, the areas affected by the July 2008 torrential rains overlapped with the hazard areas on the hazard maps, and a proper understanding of the hazard maps will help minimize the damage caused by disasters. However, according to a survey conducted in January 2019 by the Disaster Prevention Diorama Promotion Network (1,772 people surveyed), only 17.7% of respondents answered that they understand the disaster risks around them from hazard maps. Of those who have seen hazard maps, 22.2% answered that it is difficult to understand how much risk there is, indicating that it is not easy to understand the extent of inundation.
Topography has a significant impact on flooding, and is an important data source for creating hazard maps. However, it is difficult to understand the large topographic features even in the areas where people usually live. In addition, topographic maps published by the Geospatial Information Authority of Japan (GSI) include buildings and other structures, making it sometimes difficult to decipher contour lines, especially in urban areas.
Therefore, in order to promote understanding of flood hazard maps, this study aimed to develop 3DCG teaching materials that facilitate intuitive understanding of topographical features and to verify their effectiveness.
2. Creation of teaching materials
The created teaching materials can be viewed on the web. The 3DCG data of the terrain was obtained from the Geospatial Information Authority of Japan (GSI) map website. Then, 3DCG of arrows and letters were added using Blender. The created files were uploaded to the web-based platform Sketchfab and converted to USDZ format. The converted files were downloaded to iPads, which can display the created teaching materials in AR and normal display.
3. class practice and evaluation
We conducted a class practice using this teaching material for 240 second-year male junior high school students in the Tokyo metropolitan area. In the classroom practice, the inundation zones were predicted for the Shibuya and Komaba districts, using the plane topographic maps, 3DCG 3D topographic maps, and 3DCG 3D hazard maps of the respective areas. In order to separate the effect of the teaching materials from the effect of the difference in difficulty between the Shibuya and Komaba districts, two groups were set up: Group A, in which the Shibuya district was studied first and then the Komaba district was studied, and Group B, in which the Komaba district was studied first and then the Shibuya district was studied.
The evaluation of the created teaching materials was based on the results of the inundation zone prediction (comprehension survey) conducted during the class and the students' awareness survey conducted after the class. The results of the comprehension survey showed that, as an overall trend, the percentage of correct answers for inundation areas along plateaus and valleys tended to be higher with 3DCG 3D topographic maps than with planar topographic maps. On the other hand, for depressions on the plateau, the percentage of correct answers tended to be lower for the 3DCG 3D topographic maps than for the planar topographic maps.