瑞安市属中亚热带海洋型季风气候区。暴雨引起的洪涝灾害是影响我市农业生产的主要灾害之一。据瑞安市气象站统计,1959～1983年25年出现≥50毫米的暴雨104次.平均每年3～6次。其中日雨量≥100毫米大暴雨25次,平均每年1次,由台风带来暴雨有22次,占88%。1990年晚稻生产期间,我市连续遭到4次台风袭击,特别是8月20日的12号台风和9月8日的18号台风,带来历史罕见的特大暴雨,山洪暴发,河流滞泄,大批晚稻受淹成灾。根据调查作物受害情况,晚稻受淹后各产量因素均受到不同程度的影响。其中以亩有效穗减少最为严重。随着淹水时间延长,成穗率降低,亩有效穗减少。其次是结实率、实粒数和总粒数,受淹后叶片枯萎,营养不良,结 Ruian City is a subtropical marine monsoon climate zone. Flood disaster caused by rainstorm is one of the major disasters affecting agricultural production in our city. According to statistics of Ruian Meteorological Station, torrential rains of ≥ 50 mm occurred in 104 times in 1959 ~ 1983 25 times, averaging 3 ~ 6 times per year. Among them, the daily rainfall ≥100 mm heavy rain 25 times, on average once a year, brought by typhoon 22 times, accounting for 88%. During the late 1990’s rice production, the city was hit consecutively by four typhoons, in particular the typhoon 12 on August 20 and the typhoon 18 on September 8, bringing about unprecedented heavy rainfall, flash floods and stagnant rivers , A large number of late rice flooded disaster. According to the investigation of crop damage, the yield factors of late rice submerged affected by different degrees. Among them, the decrease of acre effective acre was the most serious. With prolonged flooding time, the percentage of spikelets decreased and the number of effective panicles decreased. Followed by seed setting rate, seed number and total grain number, withered leaves after flooding, malnutrition, knot