甘肃省小麦干旱灾害风险评估及区划研究

利用1980—2016年甘肃省84个县(区)的小麦产量资料,分析平均减产率、减产率概率系数、减产率变异系数构建的综合干旱灾害风险指数,根据综合干旱灾害风险指数来评估甘肃省各市小麦单产干旱灾害风险。结果表明:河西地区干旱发生频率高,属于灌溉农业,变异系数较大,其东部地区平均减产率高,风险概率大,属于高等风险区,河西地区的西部和中部分别属于低等和中等风险区;陇中地区干旱发生频率高,属于雨养农业,变异系数小,而平均减产率和风险概率较高,大部分属于中等风险区;陇东地区干旱发生频率较低,变异系数低,平均减产率和风险概率较高,属于中等风险区;陇南和甘南地区干旱发生频率较高,平均减产率和风险概率均较低,属于低等风险区。甘肃省小麦风险区划可为风险预算及防灾减灾提供科学依据。

Risk Assessment and Region Division of Wheat Drought Disaster in Gansu Province

Based on yield data of wheat from 84 counties (regions) in Gansu province between 1980 and 2016, on the basis of the average yield reduction rate, probability coefficient and variation coefficient of yield reduction rate, a comprehensive meteorological disaster risk index has been constructed to evaluate the meteorological disaster risk of per unit area yield in cities of Gansu province. The result shows that the frequency of drought is high in Hexi area, which belongs to irrigation agriculture, and the variation coefficient is large. The average yield reduction rate in the eastern Hexi is high and the risk probability is high, where is high risk region. The Western western and middle parts of Hexi area belong to low and medium risk areas respectively.The frequency of drought in central Gansu is high, belonging to rainfed agriculture, with small variation coefficient, and the average yield reduction and risk probability are high, most of where belong to higher risk areas. The frequency of drought in the eastern Gansu is low, the variation coefficient is low, and the average yield reduction and risk probability are high, where belongs to the medium risk zone.In the Longnan and Gannan south Gansu areas, the frequency of drought is higher,the average yield reduction and risk probability are lower and is a lower risk area.The risk based region division for wheat in Gansu could provide a scientific reference for risk budget as well as disaster prevention and reduction.