气候变化对华北冬小麦生育期和灌溉需水量的影响

Abstract

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 theNCP 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.