淮河流域冬小麦生育期水热资源时空变化及其影响

Spatiotemporal Variation and the Influences of Water and Heat Resource During the Growth Period of Winter Wheat in the Huaihe Basin

研究淮河流域冬小麦不同生长阶段水热资源时空变化特征及其影响,为该区冬小麦生产趋利避害、稳产高产提供科学依据。利用淮河流域106个气象站点1971—2010年逐日气象资料,采用MannKendall趋势检验法、线性倾向率方法、变异系数法分析了冬小麦不同生育阶段热量条件、水分条件的空间分布和时间变化特征。结果表明:淮河流域冬小麦生长期间热量条件分布不均,不同生育阶段平均气温和≥0℃积温均随时间显著增加,其中营养生长阶段增温最显著。热量条件的增加会使冬小麦生育期缩短,干物质积累减少,进而影响产量,同时冬季气温的增加有利于病虫越冬、繁殖,使冬小麦遭受病虫害的危害加重。冬小麦全生育期除沿淮西南部外,其他地区降水量均不足,其中北部地区降水量亏缺在200 mm以上;各生育阶段以并进生长阶段水分亏缺最大。40年来降水量无显著变化趋势,而北部部分地区需水量显著减少,有利于缓解降水不足对冬小麦生长的影响,沿淮大部和中东部需水量增加,导致发生干旱的风险增加;同时降水量的年际变化有增大趋势,发生旱涝灾害的风险加大,给冬小麦产量造成一定程度的损失。

In order to provide a scientific basis for promoting the advantages and avoiding disadvantages, ensuring the high and stable production of the winter wheat, the spatial distribution and the temporal variation of heat conditions and water conditions for different growth periods of the winter wheat were analyzed using the Mann-Kendall tendency verification method, the hnear tendency method and the coefficient of variation method. This based on the daily meteorological data of 106 weather stations in the Huaihe basin during 1971 to 2010. Results showed that the mean air temperature and the cumulative temperature above 0℃ had obvious geographical characteristics and the heat conditions were higher in southwest, lower in east and north. The mean air temperature and the cumulative temperature above 0℃ both increased significantly during the 40 years in different growth periods, especially in the vegetative stage. The increasing heat conditions can shorten the growth periods, reduce the dry matter accumulation and affect the yield of the winter wheat. Besides, the increasing winter temperature is beneficial to the overwintering and propagation of pests, making diseases of the winter wheat worse. The precipitation of different growth stages decreased from south to north and the water demand showed less regional differences. Precipitation cannot meet the growth needs of the winter wheat in most regions of the study area except southwestern part along the Huaihe. The rainfall deficit of the northern part was greater than 200mm, and was biggest in vegetative and reproductive growth phase. The change trend of the precipitation during g0 years was not significant. The significant decreasing water demand in parts of the the risk of droughts. Meanwhile the greater inter-annual variation of precipitation increased the risk of droughts and floods, which took a part yield loss of winter wheat. To ensure the high and stable yield of the winter wheat, the agricultural department needs to nurture new varieties of high yield and strong resistance and increase investment in infrastructure construction to enhance the comprehensive capacity of agricultural disaster prevention and mitigation.