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利用华北地区48个农气站冬小麦发育期资料(1981-2010年)和气象资料(1961-2010年)以及近50 a产量资料,将冬小麦全生育期划分为前期(播种期—起身期)、中期(拔节期—开花期)、后期(灌浆期—成熟期)3个阶段,并考虑了底墒形成期(播种当年7-9月)内的降水。通过构建干旱指数,分析不同发育阶段干旱灾害的时空分布规律。根据典型灾害年份的减产率数据,将不同发育阶段干旱灾害造成的灾损情况进行了量化,并以权重系数的形式来反映干旱危险性的贡献大小。最后利用GIS技术绘制了华北地区干旱危险性区划图。结果表明:(1)华北地区冬小麦各发育阶段均受到干旱威胁,其中中期水分亏缺最为严重。(2)冬小麦平均干旱指数空间分布在前期和后期由东南向西北递增,在中期由南向北递增。(3)华北地区冬小麦前期危险性权重系数由南向北逐渐增大,而中期危险性权重系数由北向南逐渐增大。
Based on the data of winter wheat development in 48 agricultural stations in North China (1981-2010) and meteorological data (1961-2010) and the yield data of nearly 50 years in North China, the whole growth period of winter wheat was divided into the early stage (sowing-up period) Mid-stage (jointing-flowering stage), late stage (filling stage-maturity stage) and taking into account the precipitation during the period of soil moisture formation (July-September of the year of sowing). By constructing drought index, the spatial and temporal distribution of drought disaster at different developmental stages was analyzed. According to the yield reduction data of typical disaster years, the disastrous situation caused by drought disaster at different developmental stages was quantified, and the contribution of drought risk was reflected by the weight coefficient. At last, the regional zoning map of drought hazard in North China is drawn by GIS technology. The results showed that: (1) All stages of winter wheat in North China were under the threat of drought, of which the water deficit was the most serious in the middle period. (2) The spatial distribution of average drought index of winter wheat increased from southeast to northwest in the early and late stages, and increased from south to north in the middle period. (3) The hazard coefficient of early winter wheat in North China gradually increased from south to north, while the mid-term risk weight coefficient increased gradually from north to south.