气候变化下辽西北春玉米生育期需水量研究

Water requirements of spring maize in Northwest Liaoning Province under climate change

作物需水量是制定灌溉用水计划和水资源规划的重要依据,了解其历史变化和未来发展趋势对预测农作物用水走势并据此制定合理决策至关重要。本文基于辽西北地区9个气象站1964—2013年的气象及土壤资料,采用FAO推荐的Penman-Monteith模型与充分灌溉条件下的土壤水分密度函数法获得春玉米不同生育期需水量,并预测了未来气候变化对辽西北春玉米净灌溉需水量的影响。结果表明:1964—2013年近50年辽西北春玉米需水量基本呈现不显著下降趋势,空间分布规律为自东南向西北方向逐渐递增;净灌溉需水量多年平均值为402.44mm,灌溉需求指数多年平均值为0.67;从未来气候变化情境下的净灌溉需水量来看,国内或区域内资源(A2)情景与区域可持续发展(B2)情景在未来30a距平增长率依次降低。本文研究可为辽西北春玉米种植的农业用水以及合理灌溉提供依据,对缓解本地区日益突出的水资源供需矛盾具有十分重要的战略意义。

Crop water requirement is important to irrigation requirement planning and water resources planning. Understanding historical changes and future trends is critical to predicting future crop water use trends and making rational decisions. Using the Penman-Monteith model recommended by the FAO, the water requirement of spring maize across the whole plantation in northwestern Liaoning was calculated. The net water requirement of spring maize at different growth stages was obtained by soil moisture density function under full irrigation conditions. We found that potential evapotranspiration and spatial and temporal variation in water demand indicates that spring maize increased and decreased over the last 50 years. In the past 50 years, the water demand of spring maize in northwestern Liaoning has not decreased over time. The spatial distribution has gradually increased from southeast to northwest. From net irrigation water demand,the average annual net irrigation water requirement of spring maize in northwestern Liaoning was402.44 mm, and average annual irrigation requirement index was 0.67. From the perspective of net irrigation water demand under future climate change scenarios, domestic or regional resources（A2）scenarios and regional sustainable development（B2） scenarios, the 30 a growth rate decreased in turn. This study provides a basis for agricultural water use and reasonable irrigation of spring maize planting in the northern Liaoning. It is of great strategic significance to the increasingly prominent contradiction between supply and demand of water in this region.