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根据1961-2010年陕西省的逐日降水量资料,运用标准化降水指数(SPI)法、Morlet小波分析法,分析了干旱的时间变化特征、周期变化特征和空间变化特征。结合2007-2010年陕西省17县(区)的玉米产量资料,借助面板数据模型,就干旱对陕西省玉米单产的影响效应进行了研究。结果表明:陕西省干旱趋势逐渐增强,以20世纪90年代干旱最为严重;陕西省干旱的危害程度由北向南逐渐降低,陕北的危害最严重,关中次之,陕南最轻;同时,陕西省年干旱时间序列存在显著的准2~4a和准4 a尺度周期变化规律;另外,干旱与玉米产量呈显著的负相关,干旱指数(标准化降水指数)等级每增加一个级别,将导致陕西省每hm2耕地玉米产量减少128.985 kg。期望研究结果能为陕西省针对干旱气象灾害制定相应的减灾政策,有助于保障陕西地区玉米生产的稳定。
According to the daily precipitation data of Shaanxi Province from 1961 to 2010, the temporal variation characteristics, periodic variation characteristics and spatial variation characteristics of drought were analyzed using the standardized precipitation index (SPI) method and the Morlet wavelet analysis method. Based on the data of maize yield from 17 counties (districts) in Shaanxi Province during 2007-2010, the effect of drought on maize yield in Shaanxi Province was studied by panel data model. The results showed that: the drought trend in Shaanxi Province gradually increased, with the most serious drought in the 1990s; the extent of the drought in Shaanxi Province gradually decreased from north to south, the worst in northern Shaanxi, the second highest in Guanzhong, and the lightest in southern Shaanxi; meanwhile, In addition, there was a significant negative correlation between drought and maize yield, and each increase of drought index (standardized precipitation index) level by one level would result in the increase of annual drought time series in Shaanxi province Production of corn per hm2 arable land decreased by 128.985 kg. It is hoped that the research results can formulate the corresponding disaster mitigation policies for drought meteorological disasters in Shaanxi Province and help to ensure the stability of corn production in Shaanxi Province.