气候变暖下东北地区春玉米生产潜力变化分析

针对干旱气候变化及其对淮河流域夏玉米的可能影响，基于历史灾损构建的致灾阈值模型，应用第5次耦合模式比较计划（Coupled Model Intercomparison Project Phase 5，CMIP5）中的5个全球气候模式（GCMs）和3种典型浓度路径（RCPs）情景输出的逐日气温和降水量数据，计算不同RCPs情景下致灾阈值以上气象干旱发生频率，结合承灾体的暴露度和脆弱性，构建干旱灾害风险评估模型，开展淮河流域21世纪近期（2020—2039年）、中期（2040—2069年）和远期（2070—2099年）夏玉米抽雄—乳熟期卡脖子旱风险预估。结果表明：不同气候模式对淮河流域的气温和降水量具有较好的模拟能力，气温模拟效果更佳。未来夏玉米抽雄—乳熟期将有所提前，该生育期日数缩短；预估未来淮河流域夏玉米抽雄—乳熟期气象干旱日数年际变幅大，从其线性趋势看，RCP4.5和RCP8.5情景下气象干旱日数线性趋势不明显，而RCP6.0情景下线性增加显著。在致灾因子及承灾体的综合影响下，未来淮河流域夏玉米卡脖子旱风险年际波动大，干旱灾害风险增大，21世纪各时期，其风险远期最高、中期最低；不同情景由低向高排放情景下干旱风险依次增高。预估的干旱风险空间差异明显，总体上该流域北部风险高于南部、西部高于东部。

A trend-preserving bias correction: the ISIMIP approach

To evaluate the climate variation of drought and its possible effect on summer maize in the Huaihe River basin, we have used the five General Circulation Models (GCMs) from the fifth coupling model comparison scheme (CMIP5) and the diurnal temperature and precipitation data under three representative concentration pathways (RCPs) to calculate the frequency of drought beyond the different disaster-causing thresholds based on the historic disaster losses. Combined with the vulnerability and exposure of hazard-affected bodies, we have established a regional disaster drought risk evaluation model, and conducted a risk estimation to the choking drought disaster occurred in heading-milking period of summer maize in the Huaihe River basin in the near term (2020-2039), medium term (2040-2069) and long term (2070-2099) in the 21st century. The results show that the five GCMs have good ability in simulating temperature and precipitation in the Huaihe River basin, especially temperature. The heading-milking period (critical period of water sensitivity) of summer maize will be ahead of schedule, and the growth period will be shortened. It is estimated that the inter-annual change of the choking drought days in the heading-milking periods of summer maize in the Huaihe River basin is large in the future. Linear change trends of the choking drought days of summer maize are not significant under RCP4.5 and RCP8.5 scenarios, although this linear increased trend is significant under RCP6.0 scenarios. Affected by the disaster-causing factors and the hazard affected bodies, the inter-annual fluctuation of choking drought risk of summer maize in Huaihe River basin will be large in the future. The overall drought risk will increase compared to the base period. In terms of different periods, the risk of drought disaster can be the lowest in the medium term, the second in the near future, and the highest in the long term. The choking drought risk in the different scenarios increases from low to high emissions. It is estimated that the risk of drought disaster of summer maize has an obvious spatial difference, and the drought risk in the western and northern parts in the Huaihe River basin can be higher than those in the eastern and southern parts.