| Study on methodology for risk assessment and division of winter wheat drought hazard in Hebei Province |
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| DOI：10.7606/j.issn.1000-7601.2009.02.03 |
| Key Words: Hebei Province winter wheat drought risk division |
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| Abstract: |
| Different levels of dry years was defined respectively by the ±0．5 times and ±1．5 times standard deviational sample variance of the mean values of annual precipitation and then winter wheat dry disaster year was confirmed by whether the meteorological equivalent yield reduction rate was greater than 3％．In addition analysis was made of the average winter wheat yield reduction rate in dry years and its spatial distribution in various areas of Hebei Province and study was also made on the frequency distribution law of the winter wheat drought hazard with different intensities．From point of view on risk analysis of disasters it presented a methodology for risk assessment and division of winter wheat drought hazard in Hebei Province including the concept calculation method and regional distribution of the disaster risk index．The average decreasing rate drought hazard risk indexes and annual precipitation were selected as factors dominating insurance of drought hazard based on which the winter wheat growing zone might be divided into three grades such as light moderate and severe under the support of GIS．The average decreasing rate the disaster prevention and mitigation measures of dry year with different intensities and loses were also dicussed in different kind of risk areas． |