洪灾是指一个流域内因集中大暴雨或长时间降雨,汇入河道的径流量超过其泄洪能力而漫溢两岸或造成堤坝决口导致泛滥的灾害。我国的洪水灾害主要集中在东部,大多发生在7月至9月这三个月。今年夏季,许多现代化城市都受到了罕见的暴雨侵袭。一些城市出现严重内涝——街道成河、汽车没顶、交通堵塞、人员伤亡……洪水肆虐。 Flood refers to a river basin due to heavy rainfall or prolonged rainfall, the amount of runoff into the river exceeds its ability to flood spillover across the Taiwan Strait or lead to flooding caused by flooding. Flood disasters in our country are mainly concentrated in the east, mostly in the three months from July to September. This summer, many modern cities are hit by rare rains. Serious waterlogging in some cities - street into rivers, cars not top, traffic jams, casualties ... floods raging.