Investigation and Analysis of Torrential Rain and Flooding Caused by Typhoon Lekima in Wenzhou City, Zhejiang Province

Typhoon Lekima, the 9th typhoon of 2019, had the maximum wind force of 16 levels near the center when it made landfall. The typhoon traversed through Zhejiang and Jiangsu provinces and then moved into the Yellow Sea. This paper systematically studies and explains the typhoon profile, intensity of heavy rain, flood investigation analysis, and disaster statistics. The research results show that the center of the heavy rain from Typhoon Lekima mainly appeared in the northern part of Wenzhou City, including Yueqing City and Yongjia County. The characteristics of the heavy rain are strong rainfall, concentrated precipitation, and uneven spatiotemporal distribution. Among them, the maximum hourly rainfall at the Fuxikou Reservoir station reached 168.5 millimeters, with a rainfall intensity of once in 200 years. The flood peak water level at the Shi Zhu station of the Nanxi River reached 28.14 meters, and the measured flood peak flow was 6,000 cubic meters per second, which is the second largest flood peak since the founding of the People's Republic of China. At the same time, the intensity of several short-duration heavy rains exceeded historical records, leading to flash floods and urban and rural waterlogging disasters. Following the outbreak of mountain torrents, some areas suffered severe damage. Therefore, this paper suggests strengthening the construction of disaster prevention and mitigation infrastructure, enhancing flood monitoring and early warning capabilities, and strengthening public awareness of disaster prevention in order to further improve the disaster prevention and mitigation system and enhance the ability of grassroots communities to respond to natural disasters.