中国西北气候变暖及其对农业的影响对策

摘要

以全球气候变暖和区域降水变率增加为主的气候变化给农业生产和人类食品安全带来严峻挑战.认识气候变化对农业的影响,提出科学的技术对策,是应对气候变化的基础.基于西北5省区气象观测资料,分析西北地区近52年(1961—2012年)气候时域趋势变化和空间分布特征,对比讨论了气候变化对西北农业的主要影响,提出了西北旱作农业应对气候变化的适应技术对策.结果表明,近52年来,西北区域气温呈显著上升趋势,气温变化倾向率为0.312℃/10 a,从20世纪70年代开始气温持续上升,气候变暖的突变点在1991年.西北区域降水量趋势变化空间差异明显,以黄河沿线为界,黄河以西区域降水量呈增多趋势,黄河以东区域呈减少趋势,并且降水量减少的幅度明显高于增加的幅度.气候变暖对农作物生长生育、植物形态结构、产量形成及品质等生理生化过程产生重大影响,对作物种植结构、栽培方式、种植制度,农田耕作层土壤生态环境等也产生了重大影响.要通过优化农业种植结构、调整作物种植制度、改进作物栽培方式、改良作物品种、加强水肥系统协调管理等技术措施来适应气候变化.科学开发利用气候资源,减缓气候变暖的不利影响,积极应对全球气候变化.%Agricultural production and human food safety are facing a severe challenge because of the climatic change which is mainly involved with the warming of global climate and the rising of rainfall changing rate. It is the basis for treating against the climate change by knowing the impact of climatic change on agriculture and finding out scientific and technical measures. Based on the meteorological data observed in five provinces (districts) in Northwest China, the temporal and regional trend and spatial distribution characteristics of climatic change in Northwest China in 1961—2012 were studied, the main impact of climatic change on agriculture in Northwest China was discussed by comparison, and adaptive technical measures for dry farming in Northwest China against climatic change was brought forward. The result showed, in the recent 52 a, the air temperature in Northwest China rose significantly, and the trend rate of air temperature change was 0.312 ℃/10 a, the air temperature kept rising from the beginning of 1970s, and the discontinuity point of climatic warming was in 1991. The rainfall changing trend in Northwest China was distinct with a spatial difference, by the border of the Yellow River, rainfall was increasing in the western region while it was decreasing in the eastern region, and the amplitude of rainfall decreasing was distinctly higher than the amplitude of increasing. Climatic warming significantly impacts not only the physiological and biochemical process including crop growth, plant morphology and structure, yield formation and quality, but also the crop planting structure, culturing mode, planting system, and the soil ecological environment in the cultivated farm horizon. Climatic change can be adapted to by optimizing the agricultural planting structure, adjusting the crop planting system, improving the crop culturing mode, upgrading the crop species and enhancing the water-fertilizer coordination, etc. The global climatic change can be challenged by developing and using climatic resources scientifically, and relieving the adverse impact of climatic change.