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利用华北平原冬小麦-夏玉米一年两熟种植典型区域北京地区1962—2011年逐月降水、温度资料计算多尺度标准化降水指数(SPI)和标准化降水蒸散指数(SPEI),分析干旱对作物产量的影响。结果显示:1)在过去50年内,SPI与SPEI所评判的干旱演变有巨大的不同,SPEI对气候变暖的响应是造成上述现象的主要原因。2)1990—2011年干旱指数与作物产量的关系显著(P<0.05),短时间尺度的SPI3-8和SPEI3-8与玉米气候产量呈曲线关系,所建立的回归方程可以解释60.0%和60.1%的玉米产量变异,适宜的干湿状态在-0.8到3.2(SPI)和-0.9到2.1(SPEI)之间。3)长时间尺度的SPI24-5和SPEI24-5与冬小麦气候产量呈线性相关,可以解释其51.8%和51.2%的产量变异。研究结果符合北京地区玉米以雨养为主、冬小麦以地下水补灌为主的实际情况。4)利用12或24个月尺度的干旱指数判断区域水分状况,可以帮助决断冬小麦返青后的灌水次数和灌水量,在防范产量风险的同时,提高水资源的利用效率。本研究表明,选择适合的时间尺度和月份的SPI和SPEI可以用来评价华北平原旱涝状况对农业生产的影响。降水量缺乏仍然是导致北京地区作物减产的主要因素。但华北平原由于气温升高导致干旱化的趋势明显,未来研究华北平原干旱对作物产量的影响,需更加注重运用综合了降水和蒸散因素的干旱指数,以提高评价干旱对产量影响的准确性。
Based on the monthly precipitation and temperature data from 1962 to 2011 in Beijing, the multi-scale standardized precipitation index (SPI) and normalized evapotranspiration index (SPEI) were calculated by using the typical region of double-cropping of winter wheat and summer maize in North China Plain. influences. The results show that: 1) The evolution of drought judged by SPI and SPEI is quite different in the past 50 years. The response of SPEI to climate warming is the main reason for the above phenomenon. 2) The relationship between drought index and crop yield was significant (P <0.05) from 1990 to 2011. The short-time scale SPI3-8 and SPEI3-8 showed a curve relationship with the yield of maize. The established regression equation could explain 60.0% and 60.1 % Of maize yield variation, with a suitable dry-wet status of between -0.8 to 3.2 (SPI) and -0.9 to 2.1 (SPEI). 3) The long-term SPI24-5 and SPEI24-5 are linearly correlated with the winter wheat crop yield, which can account for 51.8% and 51.2% yield variability. The research results are in line with the fact that the rain-fed corn is the main source of corn in Beijing and the recharge of winter wheat is mainly groundwater. 4) Using the 12 or 24-month drought index to judge the regional water status can help determine the frequency of irrigation and the amount of irrigation after the greening of winter wheat and increase the utilization efficiency of water resources while preventing the risk of yield. This study shows that the selection of suitable time scales and months of SPI and SPEI can be used to evaluate the impact of drought and flood conditions in North China on agricultural production. The lack of precipitation is still the main factor that has led to crop cuts in Beijing. However, due to the obvious trend of drought in the North China Plain due to the temperature increase, it is necessary to pay more attention to the use of the drought index that integrates the factors of precipitation and evapotranspiration in order to improve the accuracy of evaluating the impact of drought on the yield in the future.