黄淮平原冬小麦灌溉需水量的影响因素与不同年型特征

Irrigation water requirement by winter wheat in Huanghuai Plain: Affecting facto rs and characteristics in different climatic years.

以黄淮平原区80个气象站点46～54年的降水资料和10个站点100cm深度的土壤湿度资料为基础,运用麦田水分平衡原理,分析了冬小麦灌溉需水量与冬小麦需水量、生育期降水量和土壤底墒水的关系,并就不同气候年型分析了冬小麦灌溉需水量的变化特征。结果表明:黄淮平原冬小麦灌溉需水量等值线基本呈纬向分布,自南向北逐渐增大。正常年零值线位于许昌、扶沟、柘城、鹿邑、亳州、萧县至徐州一带,此线附近冬小麦需水量和供水量基本平衡,可以不进行灌溉或进行少量灌溉;此线以北则必须进行灌溉,其灌溉量愈向北愈大,依次为60～100和100～190mm,要分别灌1～2水和2水;此线以南,可不进行灌溉。丰水年零值线北移约0.5～1.0个纬度,全区灌溉面积和灌溉量明显减小。欠水年零值线南移约1.0～1.5个纬度,灌溉面积和灌溉量显著增大。

By using the last 46-54 years precipitation data from 80 meteorological stations and the 0-100 cm soil water content data at 10 stations in the Huanghuai Plain, the relationships between the irrigation water requirement and water requirement by winter wheat, and between the precipitation in winter wheat growth season and the soil water content at planting time were analyzed, based on the principles of farmland water balance. In the meantime, the characteristics of irrigation water requirement by winter wheat in different climatic years were studied. In the study area, the isoline of irrigation water requirement by winter wheat was basically in latitudinal distribution, with the requirement increased gradually from south to north. In normal years, the zero isoline was located in Xuchang-Fugou-Zhecheng-Luyi-Bozhou-Xiaoxian-Xuzhou. Along this line, the water requirement by winter wheat was in balance with water supply, and no or less irrigation was required. However, in the north of this line, irrigation should be made, with the irrigation amount increased northward, being about 60-100 mm and 100-190 mm and irrigating 1-2 times or 2 times. In the south of this line, no irrigation was required. In the years of plentiful precipitation, the zero isoline moved northward by 0. 5-1.0 latitude, and the irrigation area and irrigation amount decreased obviously ; while in the years of short precipitation, the zero isoline moved southward by 1.0-1.5 latitude, and the irrigation area and irrigation amount increased obviously.