洪涝灾害的形成及其防御措施洪涝灾害是由暴雨和连阴雨造成的。其主要天气系统是冷锋、静止锋、锋面气旋和台风。冷锋活动可产生大范围、强度较大的锋面雨；锋面气旋经过，往往有较长时间的降水；台风暴雨主要发生在夏秋季节，有时台风和西风小槽结合，会产生特大暴雨。例... Formation of floods and their defensive measures Floods and floods are caused by heavy rains and even overcast and rainy days. Its main weather system is cold front, static front, frontal cyclone and typhoon. The cold fronts can produce large-scale and intense frontal rain. The frontal cyclones often have long-term precipitation. The typhoon torrential rain mainly occurs in the summer and autumn seasons. Sometimes the typhoon and westerly winds combine to produce heavy rainstorms. example...