近60年东北地区春玉米旱涝趋势演变研究

Evolution of drought and flood trend in the growth period of spring maize in Northeast China in the past 60 years

  • 摘要: 区域作物旱涝趋势的演变是区域应对气候变化、制定防灾减灾决策的理论依据,是保证我国粮食安全的基础。本文以东北地区为研究区,依据春玉米的生长特征将其划分为14个分区,利用研究区1958-2017年78个站点的逐日气象数据,计算春玉米生育期内的累积水分盈亏指数(CWSDI'),并将其划分为8个旱涝等级,结合M-K趋势检验和突变检验法及GIS空间分析技术,揭示了东北地区春玉米生长期旱涝趋势的时空演变规律。结果表明:在春玉米生育期内,播种-抽穗期的3个生育阶段,CWSDI'值大体呈上升趋势,抽穗-成熟期CWSDI'值呈下降趋势,其中乳熟-成熟阶段的下降趋势最重,但无明显区域性。研究区内春玉米干旱的发生频率远高于洪涝的发生频率,干旱自20世纪90年代逐渐加重,洪涝情况无明显变化趋势;拔节-抽穗阶段和乳熟-成熟阶段分别是旱涝灾害最轻和最重的阶段,春玉米各生育阶段各旱涝等级的发生频率大体上是特旱>轻旱>其余旱涝等级;吉林省西部和辽宁省西部的中旱及重旱频率高于其他地区,特旱主要集中在研究区西部,轻涝集中在黑龙江省中、南部,吉林省东部和辽宁省东部,研究区内几乎不发生中、重涝。应在春玉米的生育初期和后期注意旱涝灾害的预防,研究区西部的旱情较重应重点防范,做到适时有效灌溉。研究结果可为区域预测农业旱涝灾害、优化水资源配置提供决策依据。

     

    Abstract: The evolution of regional drought and flood trend provides a theoretical basis for understanding crop response to climate change, decision making on disaster prevention and reduction, and ensuring China's food security. Here, the northeast region of China was used as the research area, which was divided into 14 parts based on the growth characteristics of spring maize. The daily meteorological data from 78 stations in the study area from 1958 to 2017 were used to calculate the crop water surplus deficit index (CWSDI') of spring maize during the growing period. The CWSDI' values were divided into eight drought and flood levels. The results revealed the temporal and spatial trend of drought and flood during the growth period of spring maize in the northeast region using Mann-Kendall trend test, mutation test, and geographic information system spatial analysis technology. During the growth period of spring maize, CWSDI' generally increased in the three growth stages of sowing-heading period and decreased in the heading-maturation stage, and the decreasing trend was the most significant in the milk-maturation stage, but without any obvious regional difference. The frequency of drought in the growth period of spring maize in the research area was considerably higher than that of flood. The drought situation had gradually worsened since the 1990s, but the flood situation showed no obvious change. The jointing-heading and milk-maturation stages were the least and most affected stages by drought and flood, respectively. The frequency of drought and flood in each growth stage of spring maize was as follows:extreme drought > light drought > other drought and flood levels. The frequency of moderate drought and heavy drought in the western part of Liaoning was higher than that in other areas. Extreme drought mostly occurred in the western part of the study site, whereas light flood mostly occurred in Heilongjiang. Moderate flood and heavy flood rarely occurred in the study site. In the future, efforts should be made to prevent drought and flood in the early and late growth stages of spring maize. Furthermore, more attention should be paid to the western part of the study site owing to the more severe drought situation in order to achieve timely and effective irrigation. The results will provide a basis for the prediction of agricultural drought and flood disasters and optimization of water resource allocation on a regional scale.

     

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