1961-2017年黄淮海流域主要农作物需水量和缺水量时空演变研究

Study on the Spatio-temporal Evolution of Water Demand and Water Shortage of Main Crops in Huang-Huai-Hai Basin from 1961 to 2017

作物需水量和缺水量的时空演变特征对种植区农业水资源的合理分配和农业灌溉方案的科学制定具有重要的指导意义。基于黄淮海流域186个气象站点1961—2017年的气象数据,采用Penman-Monteith公式和作物系数法,计算该流域春(冬)小麦和夏玉米的需水量、有效降水量以及缺水量。利用线性倾向估计、Mann-Kendall检验和空间插值法对黄淮海流域春(冬)小麦和夏玉米需水量和缺水量的年际变化趋势和空间分布特征进行分析。结果表明:①在时间上,1961—2017年春(冬)小麦和夏玉米多年平均需水量和缺水量都呈现先下降后上升的趋势,20世纪60年代到80年代末期、90年代初期下降,90年代初期以后上升。下降阶段,春小麦、冬小麦、夏玉米的需水量变化率分别是10.5060、-14.5235、-7.3454 mm/(10年),缺水量变化率分别是-18.6054、-12.1805、-18.2085 mm/(10年)。上升阶段,春小麦、冬小麦、夏玉米的需水量变化率分别是20.0158、0.6310、7.7833 mm/(10年),缺水量变化率分别是14.1492、8.4847、6.7295 mm/(10年)。②在空间上,就需水量而言,春小麦呈现自西向东逐渐递增的分布特征,冬小麦和夏玉米呈现中部较高、东西两部较低的分布特征;这3种作物的需水量变化率均呈现出由西向东逐步减少的分布特征,春小麦、冬小麦、夏玉米需水量变化率范围分别是-4.44~-2.25 mm/年、-5.40~3.97 mm/年和-4.56~5.32 mm/年。就缺水量而言,春小麦由东西两端向西北部和北部递增分布,冬小麦由西向东递增分布,夏玉米由东西两端向中部递增分布;春小麦缺水量变化率呈现出由中部向东西两端递增的分布特征,冬小麦缺水量变化率呈现出由西北向东南递增的分布特征,夏玉米缺水量变化率呈现出由东西两端向中部递增的分布特征,春小麦、冬小麦、夏玉米缺水量变化率范围分别为-394.05万~9.76万m^(3)/年、-1368.96万~934.98万m^(3)/年和-329.25万~1030.73万m^(3)/年。

The spatio-temporal evolution characteristics of crop water demand and water shortage have important guiding significance for the rational allocation of agricultural water resources in the planting area and the scientific formulation of agricultural irrigation schemes.Based on the meteorological data of 186 meteorological stations in the Huang-Huai-Hai Basin from 1961 to 2017,the Penman-Monteith formula and crop coefficient method are used to calculate the water demand,effective precipitation and water shortage of spring wheat,winter wheat and summer maize in the basin.Based on linear tendency estimation,Mann-Kendall test and spatial interpolation method,the inter-annual variation trend and spatial distribution characteristics of water demand and water shortage of spring(winter)wheat and summer maize in the Huang-Huai-Hai Basin are analyzed.The results are as follows.Firstly,in terms of time,the multi-year average water demand and water shortage of spring(winter)wheat and summer maize from 1961 to 2017 showed a trend of first decreasing and then increasing.It decreased from the 1960s to the late 1980s and the early 1990s,and increased after the early 1990s.In the declining stage,the change rates of water demand for spring(winter)wheat and summer maize were 10.5060(-14.5235)and-7.3454 mm/(10 a),respectively,and the change rates of water shortage were-18.6054(-12.1805)and-18.2085 mm/(10 a),respectively.In the rising stage,the change rates of water demand for spring(winter)wheat and summer maize were 20.0158(0.6310)and 7.7833 mm/(10 a),respectively,and the change rates of water shortage were 14.1492(8.4847)and 6.7295 mm/(10 a),respectively.Secondly,in terms of spatial water demand,spring wheat showed a gradually increasing distribution from west to east,while winter wheat and summer maize showed a higher distribution in the middle and a lower distribution in the east and west.The variation rates of water demand of the three crops showed a decreasing trend from west to east.The variation rates of water demand of spring(winter)wheat and summer maize were-4.44 to-2.25 mm/a(-5.40 to 3.97 mm/a)and-4.56 to 5.32 mm/a,respectively.In terms of water shortage,the distribution of spring wheat increased from east and west to north and northwest,winter wheat increased from west to east,and summer maize increased from east to middle.The water shortage rate of spring wheat increased from the middle to the east-west,the water shortage rate of winter wheat increased from the northwest to the southeast,and the water shortage rate of summer maize increased from the east to the middle.The variation rates of water shortage in spring(winter)wheat and summer maize were-3940.5 thousand to 97.6 thousand m^(3)/a(-13689.6 thousand to 9349.8 thousand m^(3)/a)and-3292.5 thousand to 10307.3 thousand m^(3)/a,respectively.