黄淮海农作区玉米需水量时空变化特征比较研究

Comparison of temporal and spatial variation of water requirements of corn in Huang-huai-hai farming system region

鉴于作物需水量变化趋势对制定灌溉策略与区域水资源配置的重要作用,依据黄淮海农作区50个标准气象站点50年逐日气象数据资料,基于SIMETAW模型,分析了黄淮海各农作亚区夏玉米、春玉米生育期需水量、灌溉需要量的时空变化趋势,主要气象因子时间变化趋势以及需水量与气象因子的相关性。结果表明:1)该地区夏玉米、春玉米生育期需水量平均值分别为321.70和456.70 mm且近50年均呈下降趋势,两者降水耦合度分别为0.780、.72;2)与夏玉米生育期灌溉需要量相比,春玉米生育期灌溉需要量地区差异大且下降更显著,但两者在豫西丘陵山地旱坡地一熟水浇地二熟区均呈上升趋势;3)夏玉米、春玉米需水量下降受太阳辐射、温度、平均风速、平均相对湿度、降水的综合影响,其中最主要气候原因为太阳辐射、温度;平均风速、降水量与之呈显著负相关,其他各因素为显著正相关。

Information of crop water requirement and its temporal and spatial change are important for irrigation scheduling, water resources planning and future decision-making. Based on the observed daily meteorological data in 1960- 2009 of 50 normal meteorological codes in Huang-huai-hai farming region, the water requirements and irrigations of summer corn and spring corn were calculated by SIMETAW model. The results showed that water requirements of summer corn and spring corn are 321.70 and 456.70 mm respectively,which showed a significant downtrend in the past 50 years and the rainfall coupling degrees of summer corn and spring corn were 0.78 and 0.72 respectively. Compared with irrigations of summer corn,irrigations of spring corn had a significant downtrend and had significant differences in different regions,which showed a significant uptrend in the south of Shaanxi and Shanxi provinces; The downtrend of corn water requirement in Huang-huai-hai farming region mainly attributed to the reduction of solar radiation,which was also affected by other climatic factors. Wind speed, precipitation had negative correlations with the water requirements of summer corn and spring corn,while other climatic factors had positive effects.