中文摘要：

农业易受旱涝影响造成严重损失,关于农业旱涝灾害气象因子的致灾阈值研究,在点尺度上从气象致灾因子的致灾机理、人工旱涝灾害试验及田间小区建立的作物模型模拟角度定量化致灾阈值;在面尺度上进行流域数理统计、气象致灾因子的旱涝指标以及理论假设基础上的气象致灾因子阈值等研究。目前存在的不足有：（1）研究内容上,气象致灾因子的致灾过程尚不甚清晰;（2）研究方法上,以统计方法建立的面尺度气象致灾因子及其可能阈值等尚未有较好的试验佐证。未来需要加强以下研究：（1）细化点尺度气象致灾过程研究,在致灾过程中寻找致灾规律,划定相应致灾阈值。（2）实现点、面尺度的转换,而其中转换工具的选取亦是决定尺度推绎和转换能否成功的关键。

英文摘要：

Agriculture is affected by climate change most sensitively, especially prone to be affected by drought and flooding, causing serious losses. Researches on the threshold of meteorological disaster inducing factors at point scale have been carried out, such as formative mechanism in meteorological disaster inducing factors, artifi- cial experiments of drought and flood disaster and crop simulation models based on field plot, etc. Moreover, re- searches at surface scale have appeared, such as mathematical statistics in the basin, drought-flood index of mete- orological disaster inducing factors and the meteorological disaster inducing threshold based on the theoretical hy- pothesis. The major problems are as follows： formative process in meteorological disaster inducing factors is not clear on the content of study; and as for the study method, there is no suitable experimental support for meteoro- logical disaster inducing factors and its probable threshold at surface scale achieved through statistical approach. The advanced researches need to be developed as follows： after refining the formative process of meteorological disaster at point scale and finding the law, the disaster inducing threshold is defined. It is important to achieve the transformation between point and surface scale. The conversion tool is decided to the successful yardstick reason- ing and scaling convert.