A research group led by Associate Professor Tomohito Yamada of Hokkaido University has revealed that the future extreme precipitation in Hokkaido will increase significantly using the supercomputer "Earth Simulator".This is the result of collaboration with the Japan Agency for Marine-Earth Science and Technology, the Meteorological Research Institute of the Japan Meteorological Agency, the Hokkaido Regional Development Bureau of the Ministry of Land, Infrastructure, Transport and Tourism, and Hokkaido.
In August 28, three typhoons, the first in the history of observation, landed in Hokkaido, causing enormous damage.The Hokkaido Regional Development Bureau of the Ministry of Land, Infrastructure, Transport and Tourism and Hokkaido jointly set up a water disaster prevention measures review committee to predict and evaluate future impacts of climate change and take water control measures based on specific risk assessments. Should be ".Based on this, scientific predictions were made on the risks of climate change effects in the Hokkaido region.
The calculation is based on the "Ensemble Climate Prediction Database that Contributes to Global Warming Countermeasures", and a high-resolution "Large-scale ensemble calculation" (Note) with a horizontal resolution of 5 km is carried out using the regional climate model of the Meteorological Research Institute of the Japan Meteorological Agency.Since the calculation requires a huge amount of computational resources, the Japan Agency for Marine-Earth Science and Technology's supercomputer "Earth Simulator" was used.
As a result, it was found that the amount of rainfall and the frequency of heavy rainfall per hour will increase significantly in the future in the Tokachi and Tokoro river basins to be analyzed.In the Tokachi River basin, the flooded area increased by 1% and the number of flooded houses increased by 4%. In the Tokoro River basin, the flooded area increased by 2% and the number of flooded houses increased by 3%. It was found that human damage increased significantly due to the increase and the increase in inundation depth.
In the future, we will continue to analyze the effects on other river basins and the effects of climate change on small and medium-sized rivers and mountainous areas, and use detailed rainfall data based on the calculations conducted this time to analyze future changes in flood risk. The company plans to proceed with a quantitative prediction study.
Note: Considering the error of numerical calculation, perform multiple calculations by slightly changing the calculation conditions such as the initial value.
