【摘要】 干旱是影响西北地区春玉米生产的主要气象灾害。应用甘肃省1980—2011年71个县(市)的春玉米播种面积和总产量资料,以风险理论为基础,采用风险评估技术方法,探讨了甘肃省县、市春玉米产量在干旱气候条件下的波动和减产的风险水平,通过正态分布判别和偏态分布正态化,研究了西北地区春玉米不同年型减产率变化特征,分析了甘肃省玉米产量灾害风险的空间分布规律,以期为防灾减灾提供理论依据。结果显示:不同等级风险区域呈整体上分散、小面积连片的特点,河西地区减产率最高,其次为陇中地区。高风险区主要集中在陇东地区的东部,较高风险区分布在陇中、陇东大部分地区,河西地区通过灌溉可有效缓解旱灾,风险较低。不同减产率等级下风险分析可为春玉米产量风险预测及抗灾减损、农业保险指数制定和农业保险赔付等提供参考。更多还原

【Abstract】 The spring maize was seriously influenced by drought disaster in Northwest China.Based on the risk theory and risk assessment method, the spring maize acreage and total yield of 71 counties or cities in Gansu Province during 1980—2011 were analyzed to explore the risk level of fluctuation and yield reduction of spring maize production in Gansu Province under arid climatic conditions. Through the discrimination of normal distribution and the normalization of skewness distribution, we studied the variation of yield reduction rates of spring maize in different years in Northwest China and analyzed the spatial distribution pattern of spring maize production disaster risk in order to provide theoretical basis for disaster prevention and reduction. The results indicated that the risk areas of different degrees scattered on the whole and contiguous in a small area, among which the highest of rate yield occurred in Hexi Area, followed by Longzhong Area; high-risk areas mainly concentrated in the eastern part of Longdong, the higher-risk areas distributed in the most parts of central and eastern Guizhou; Hexi Area can effectively alleviate drought through irrigation, and has the lower risk. The results can provide the references for predicting the risk of yield loses, resisting drought disaster and decreasing economic loses.更多还原