基于CCSM4气候模式的未来气候变化对黑河绿洲玉米产量影响预测

Yield of the Maize in Heihe Oasis Under Climate Change in Northwest China Predicted Based on the CCSM4 Climate Model

【目的】探明未来气候变化对黑河绿洲玉米产量的影响。【方法】以研究区广泛种植的玉米为研究对象,基于第5次国际耦合比较计划(Coupled Model Intercomparison Project Phase 5,CMIP5)公布的CCSM4气候预估资料,结合DSSAT-Maize模型模拟RCP4.5和RCP8.5情景下21世纪早期、中期、末期玉米产量,分析了气候变化对玉米产量的影响,并提出了适应性措施。【结果】(1)气温是玉米生育期内未来气象因子动态变化幅度最大的,预估到21世纪末,RCP4.5情景下平均增温2.5℃左右,RCP8.5情景下增温更加明显,平均增温7.3℃左右;(2)在无任何适应性措施下,2种情景下玉米潜在产量及生育期长度均呈下降趋势,预估到21世纪末期,在RCP4.5和RCP8.5情景下分别减产15%左右和29%左右;(3)模拟验证得知,气温是影响玉米产量变化的主要因素,并进一步得出该区域玉米最佳年均气温为7℃,对应的生育期平均温度为10.5℃,当超过此温度时,玉米产量与温度呈显著负相关关系;(4)面对气候变化对玉米产量的影响,通过调整玉米种植日期,可降低气候变化对作物产量带来的负效应,模拟得到年均温度从7~12℃每增加1℃对应调整后的最佳播种日期分别为每年的4月10日、4月8日、4月3日、3月30日、3月24日及3月17日左右。【结论】未来气候变化将导致该区域玉米减产,针对未来不同升温程度通过调整播种日期可以在一定程度上降低减产量。

【Objective】Climate change is likely to affect the crop yield, and in this paper we assess its impact on maize yield in Heihe Oasis in Northwest China based on the CCSM4 climate model.【Method】We applied the DSSAT-Maize model to Yingke Irrigation District-a typical irrigation district in the middle reach of the oasis of the Heihe River Watershed in Northwest China-to simulate the impact of RCP4.5 and RCP8.5 scenarios on maize production in the 21 st century based on the CCSM4 climate provided by CMIP5. We then explored the optimal planting date to alleviate the impact of climate change.【Result】During maize growth period, temperature changed the most. It is estimated that by the end of the 21 st century, the average temperature in the study area is likely to exceed 2.5 ℃under the RCP4.5 scenario and 7.3 ℃ under the RCP8.5 scenario. The simulated results showed that both yield and growth period of the maize will decrease under the two scenarios, especially under the RCP8.5 scenario in which the yield reduction was more remarkable. The maize yield under the RCP4.5 and RCP8.5 scenarios was estimated to reduce by about 15% and 29% respectively. Scenario simulation showed that the temperature was the main factor affecting the maize yield. The optimal average annual temperature for maize growth was around 7 ℃, and the yield of maize was negatively correlated with annual mean temperature when it exceeded 7 ℃, and the average temperature during the maize growth period was 10.5 ℃. We found that adjusting the sowing date could reduce the negative effects of climate change on maize yield. Simulated results from the DSSAT-Maize model showed that under climate change, for each 1 ℃ increase in the mean annual temperature from 7 to 12 ℃, its negative impact on maize yield could be reduced by shifting the sowing date to April 10 th,April 8 th, April 3 th, March 30 th, March 24 th, and March 17 th correspondingly.【Conclusion】Climate change will result in a reduction in maize production, but adjusting the snowing date will reduce its negative effect.