气候变化对华北冬小麦生育期和灌溉需水量的影响

利用华北4个气象站点1981—2010年冬小麦的生育期数据和气象资料,研究了华北平原典型区域冬小麦在气候变化条件下的生育期及各生育阶段灌溉需水量。结果表明:(1)过去30a来,华北地区冬小麦播种期和出苗期均有推迟趋势,且高纬度站点的变化趋势明显,其他生育期则呈提前趋势,而冬小麦全生育期表现为缩短;(2)华北冬小麦灌溉需水量在空间上从北到南、自东向西逐渐递减趋势;在时间上,东西部地区灌溉需水量变化趋势相反,东部地区呈逐渐增加趋势,而西部地区呈减小趋势;(3)冬小麦生育阶段的灌溉需水量变化不相同,播种—出苗、拔节—抽穗和抽穗—乳熟期灌溉需水量表现为减少趋势,而出苗—拔节和乳熟—成熟期则表现为增加趋势。就冬小麦整个生育期而言,华北西部地区灌溉需水量(北京密云站和石家庄栾城站)有减少趋势,分别减少6.72mm/10a和8.3mm/10a;而华北东部地区(天津宝坻站和邢台南宫站)的趋势正好相反,分别增加2.6mm/10a和7.08mm/10a。6个生育阶段灌溉需水量的年际波动程度依次为:播种—出苗期乳熟—成熟期抽穗—乳熟期拔节—抽穗期出苗—拔节期播种—成熟期;(4)气象要素对灌溉需水量的影响较复杂,其中灌溉需水量同有效降水量、相对湿度呈负相关,且相关关系极显著,与生育期长度存在微负相关关系,与日照时数、平均温度和风速呈显著正相关。同时,影响各生育阶段灌溉需水量的气象要素也存在差异,主要包括有效降水量、相对湿度和风速等。

Impacts of climate change on winter wheat growing period and irrigation water requirements in the north china plain

This paper investigated impacts of climate change on irrigation water requirement for winter wheat with consideration to growing period in the North China Plain(NCP), benefitting to make irrigation scheduling and adaptive strategy. Based on data from 4 typical meteorology stations including Beijing Miyun and Shijiazhuang Nangong stations in the west and Tianjin Baodi and Xingtai Nangong stations in the east and phenology data of winter wheat during 1981 to 2010, the objective of this study is to investigate impacts of climate change on winter wheat irrigation water requirements in growth stages. The results showed that the dates of sowing stage and seeding stage delayed and the more variation of trend was at high latitudes, while the others showed an advanced trend. Then the spatial variation of irrigation water requirement in the NCP was decreasing from south to north in the past 30 years. And in temporal distribution study, there was a marked increase in east, but it was opposite in west area. The irrigation water requirement during the different growth stages made a different change with time. Except for a slight rise during the seeding to jointing stage in two stations and milky to maturity, the irrigation water requirements were reduced during the other growth periods. In the whole growth stages, the west sites were decreased by 6.72 mm/10a and 8.3 mm/10a, respectively. However, in the east sites, there was an increasing tendency of irrigation water requirements with 2.6 mm/10a and 7.08 mm/10a, respectively. Besides the order of annual fluctuation was: sowing to seeding stage > milky to maturity > heading to milk stage > jointing to heading stage > seeding to jointing stage > sowing to maturity. The influence of different meteorological elements on irrigation water requirement was relatively various. The relationship between irrigation water requirement and effective precipitation and related humidity was negative significant, to the contrary, the impact of wind speed, sunshine duration and mean temperature was positive. And correlation was slightly negative between irrigation water requirement and growth period length. The consequence would be more precise if growth period length was taken into consideration in the formula. Therefore, the main climatic factors influencing the irrigation water requirements were different in each growth stage. The prior impact factor was related humidity in jointing to heading stage, while the main factors were different between Beijing Miyun station and others even during the same period of heading to milky stage due to the different districts, which were mean temperature and related humidity, respectively. But for other growth stages, the influence of effective precipitation on irrigation water requirement was more important than other factors. Thus the results could become more realistic, which provided theoretical basis for the reasonable irrigation system and strategies of adapting to climate change.