选取贵州省19个地区1959-2011年间的气象资料,采用FAO推荐的Penman-Monteith公式和作物系数计算夏玉米全生育期和各个生育阶段的需水量,并且利用GIS分析降水量和作物需水量的空间分布,明确了夏玉米的水分需求平衡状况,结果表明:夏玉米各生育阶段降水量空间分布不均,且各生育阶段降水量相差较大;夏玉米各生育阶段需水量空间差异明显,初始生育期需水量由西向东逐渐减少,发育期和生育中期的作物需水量由西南向东北呈现逐渐增加的趋势,生育末期玉米需水量呈现中间较高,周边较低的分布趋势;玉米需水与降水在空间分布上并不匹配,在各生育阶段都表现较为明显;在夏玉米生育中后期存在较为严重水分亏缺问题,为需水临界期,应及时灌溉。
Based on the meteorological data from 19 stations of Guizhou Province,the water requirement(ETC)of summer corn of the whole growing period and different growth stages during 1959-2011 in Guizhou Province are estimated by using FAO PenmanMonteith equation and crop coefficient method.And the spatial distribution characteristics of precipitation and ETCare analyzed by GIS.The water-meeting situation of summer corn during the growing season is cleared.Results show that the spatial distribution characteristics of precipitation of different growth stages of summer corn are not uniform and differ considerably,the spatial distribution characteristics of ETCof different growth stages of summer corn are not uniform,the ETCof initial growth period reduce from the west to the East gradually,the ETCof fast growth period and the middle growth period increase from southwest to northeast,the ETCof late-growth stage decrease from the middle to around gradually;the spatial distribution characteristics of precipitation and the ETCcan't match well,which can be seen in all growth stages;there is severe water deficit and low water-meeting in middle growth period and maturity period of summer maize.The middle growth period is a key stage for the grain weight of summer corn,so timely irrigation is essential.