中文摘要：

洪涝灾害是我国最主要的自然灾害之一,其出现频率之高,影响范围之广,对农业造成损失之严重仅次于旱灾害。20世纪90年代以来,我国重大洪涝灾害更是频繁发生。通过对我国20世纪90年代以来重大洪涝灾害的特征、时空分布进行分析,揭示了其演变规律,并进一步阐释了我国重大洪涝灾害的形成机理,以期为我国农业洪涝灾害的防御和治理提供决策依据。

英文摘要：

The flood,one of the major natural disasters in China with its high frequency and wide impact,caused serious agricultural losses following the drought.Since the 1990s,floods become more frequent occurrence.Analysis on characteristics and spatial and temporal distribution of major flood disasters since the 1990s reveals its changing law,and interpret the formation mechanism of major flood disasters,thus providing decision-making basis for defense and governance of agricultural flood disaster.