[H-CG23] Adaptation to climate change and its social implementation

[HCG23-P07] The effect of urbanization on rainfall processes of landfalling tropical cyclones in the Tokyo metropolitan

*ZIWEN XI¹, KOJI DAIRAKU¹ (1.University of Tsukuba )

Keywords:climate change, tropical cyclone precipitation, urbanization

Japan has historically observed frequent tropical cyclone activity in its vicinity. Statistics from Japan Meteorological Agency show that an average of three tropical cyclones landed in Japan between 1991 to 2020. In 2019 alone, tropical cyclones caused substantial damage in eastern Japan, with an estimated cost of 1.88 trillion yen - the highest on record. The Tokyo metropolitan area is Japan's political and economic center, and its dense population, proximity to the sea, and flat terrain make it highly vulnerable to tropical cyclone impacts. Our research focuses on the precipitation associated with tropical cyclones that hit the Tokyo metropolitan area between 1981 to 2019. We use reanalysis data to analyze the mechanisms influencing differences in precipitation activity during cyclone landfall, primarily focusing on roughness and surface heat flux changes. We also compare the differences in precipitation between urban and surrounding rural regions, as it is necessary to consider the impact of urbanization - one of the human-induced factors of climate change - on the precipitation associated with tropical cyclones that hit the Tokyo metropolitan area.