黄淮海平原冬小麦种植的气候变化适应评估

水资源短缺影响黄淮海平原农业稳定和可持续发展。气候变化情景下,农业用水紧张的问题可能进一步加剧,种植制度和作物品种区域布局将面临调整。论文利用IPCC 5三种代表性温室气体浓度排放路径(RCP 2.6、RCP 4.5和RCP 8.5)的多模式集成数据,基于VIP(soilVegetation-atmosphere Interface Processes)生态水文模型,模拟了2011—2059年黄淮海平原二级子流域的水资源盈亏变化。在此基础上,针对水分亏缺最严重的子流域,设计无外来调水和维持2000—2010年调水总量水平的两种流域地下水采补均衡情景,对冬小麦种植区域的合理布局及其对产量的影响进行评估。结果表明,2050年代黄淮海平原农作物蒸散量增幅大于降雨量增幅,北部地区水分亏缺量将增加,南部地区水分盈余量则减少。在低到高的排放情景下,全区域水分盈余量下降0.1%~14.1%。两种地下水采补均衡情景下,2050年代黄淮海平原冬小麦种植面积应分别减少9.8%~11.3%和7.0%~8.8%,相应产量分别增加0~11.9%和3.0%~15.9%。适当减少冬小麦种植面积,可有效减缓黄淮海地区农业水资源的不足,保护生态环境,促进农业可持续发展。

Adaptation of Winter Wheat to Climate Change inHuang-Huai-Hai Plain

Water scarcity is a key factor for the stability and sustainability of agricultural productivity in Huang-Huai-Hai Plain. Considering water shortage may be aggravated by climate change, cropping structure should be adjusted to alleviate the worsening situation. Based on the multi-model datasets of three representative concentration pathways (RCP) emission scenarios from IPCC5, the effect of climate change on water balance at sub-basin scale during 2011-2059 was assessed by VIP (soil-Vegetation-atmosphere Interface Processes) model. For the sub-basins with most serious shortage of water resource, two groundwater balance scenarios were proposed based on the principle of groundwater exploitation and infiltration balance. One scenario (scenario A) supposes that there is no inter-basin water transfer in 2050s, the other (scenario B) supposes that the inter-basin water transfer remains the average level in 2000-2010 in 2050s. The balance between water supply and demand is kept stable by shrinking the planting area of crop with high water consumption in both scenarios. The effect of climate change on planting area and yield of winter wheat in the two scenarios was assessed by VIP model. The results showed that the rainfall surplus in the whole plain will decrease 0.1%-14.1% in 2050s from low emission scenario to high emission scenario since the crop evapotranspiration increases more quickly than the precipitation does. In the north part of the plain water deficit will be exacerbated, and in the south part of the plain rainfall surplus will decrease. With respect to water balance, the planting area of winter wheat in Huang-Huai-Hai Plain should be shrunk 9.8%-11.3% in scenario A and 7.0%-8.8% in scenario B in 2050s, however, the wheat yield will increase 0-11.9% and 3.0%-15.9% in corresponding scenario due to the CO₂ fertilization. Shrinking planting area of winter wheat can effectively mitigate the agricultural water shortage in Huang-Huai-Hai Plain. The research results can provide underpinnings for government’s decisions