| 摘要: |
| 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。 |
| 关键词: 谷物产量 华北平原 干旱 SPI SPEI |
| DOI：10.11841/j.issn.1007-4333.2013.05.05 |
| 投稿时间：2013-03-01 |
| 基金项目:公益性行业科研专项(201203031); 国家玉米产业技术体系项目(CARS-02-26) |
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| Impact of drought on grain yield in Beijing investigated by SPEI-based methods |
|
MING Bo, TAO Hong-bin, WANG Pu
|
| (College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China) |
| Abstract: |
| Drought is one of the costliest weather related natural hazards in North China Plain (NCP).This study was conducted to quantify the influence of drought on grain yield variability using drought indices.Detailed crop and weather data were collected from Beijing,providing a typical region of winter wheat-summer maize rotation system in NCP.The data collected from 1962 to 2011 provided 50 years of data,which were used to compute the SPI and the SPEI drought indices at different time scales from 1 to 24 months.(a) The SPEI and SPI showed large differences in the evolution and identification of drought conditions during the last five decades,positive temperature anomalies were the most important cause of the aforementioned differences.(b) Drought indices more strongly correlated with yield variability during the last two decades.Regression of maize climatic yield as the dependent variable and the 3-month August SPI/SPEI as the independent variable explained up to 60.0% and 60.1% of yield variability in a curvilinear relationship,respectively.Optimum SPI/SPEI values were in the range of-0.8 to 3.2 and-0.9 to 2.1.(c) Furthermore,winter wheat climatic yield and 24-month SPI/SPEI were a linear relationship,SPI24-5 and the SPEI24-5 drought indices explained 51.8% to 51.2% (P<0.01) of the variation in wheat yield.These results implied that SPI and SPEI provided the accurate assessment of drought impacts on grain yield of the NCP.(d) Based on these results it would be possible to generate preliminary estimates of drought impacts on winter wheat yield by preseason with some confidence.This could be very useful in regard to providing farmers with early warning information to plan irrigation management and prepare for potential drought conditions.In conclusion,the SPI and the SPEI showed excellent capability to identify drought impacts.The impacts of drought on grain yield were much greater,yet decreased precipitation is still the key factor in yield losses.This study identified an increase in drought severity associated with higher water demand as a result of evapotranspiration.Future researches in NCP should be focused on the drought indices based on precipitation and potential evapotranspiration,as they could reflect the better role played by global warming on drought severity,and provide more accurate assessment of drought impacts on yield variability. |
| Key words: grain yield North China Plain drought SPI SPEI |
