鲁中地区冬小麦水分盈亏及灌溉需水量的时空变化特征

摘要

利用1980—2014年鲁中地区气象资料和冬小麦生育期资料，采用Penman－Monteith模型和单作物系数计算冬小麦各生育阶段需水量，利用美国农业土壤保持局推荐方法计算有效降水量、水分盈亏指数（CWSDI）和灌溉需水量，对冬小麦不同生育阶段的需水量、有效降水量、水分盈亏指数及灌溉需水量时空变化进行分析。结果表明：近35 a来，鲁中平原地区冬小麦全生育期需水量呈弱的减少趋势，山区呈增加趋势；拔节—乳熟期是需水量最大的阶段，呈减少趋势，强度中心在中部地区。有效降水量全生育期呈减少趋势，拔节—乳熟期呈增加趋势，强度中心在中部地区；除平原地区的越冬期外，其它生育阶段有效降水量呈减少趋势。CWSDI全生育期呈减少趋势，乳熟—成熟期减少幅度最大，自中部向南北两边递减。为满足冬小麦需水要求，全生育期平均灌溉需水量515 mm，呈上升趋势，强度中心在西部地区，拔节—乳熟期是灌溉需水量最大的阶段，呈减少趋势，返青—拔节期是增加趋势最明显的阶段。%Based on meteorological observations and data of growth period of winter wheat from 1980 to 2014 in the middle area of Shan-dong Province,the water demand in different growth stages of winter wheat was calculated by Penman-Monteith model and single crop coefficient,and the effective precipitation,crop water surplus deficit index (CWSDI)and irrigation water requirement were calculated by the recommended method of the United States Department of Agriculture Soil Conservation Board firstly,then the temporal and spa-tial characteristics of water demand,effective precipitation,CWSDI and irrigation water requirement in different growth stages of winter wheat were analyzed.The results show that water demand during the whole growth period had a slight shrinking tendency in the plain area but an increasing trend in the mountain area during the recent 35 years.During jointing-milk stage water demand was most and it presented decreasing trend,and the change center was in the middle area.The effective precipitation during the whole growth period had a decreasing trend,while during jointing-milk stage it had an increasing trend,and the change center was in the middle area. Except for over wintering stage in the plain area,it had a decreasing trend during the other stages.The CWSDI during the whole growth period had a decreasing trend,and it had a maximum amplitude during the milk-mature stage.It decreased from the middle to both sides.In order to meet the need of water demand of winter wheat,the averaged total supplementary irrigation amount was 5 15 mm,and it had an increasing trend and the change center was in the western area.During the jointing-milk stage water requirement was most and it showed a decreasing trend,and there was a significant increasing trend during the returning green-jointing stage.