河北省 5 个县域冬小麦-夏玉米连作灌溉需水特性分析

利用河北平原区5个县域及周边的雨量站、气象站和农气站资料,综合考虑降水、土壤和作物特性,提出修正的SCS-CN模型用于计算作物有效降水量,采用FAO推荐的Penman-Monteith公式和作物系数法计算作物需水量,探讨研究区不同水文年份作物灌溉需水量的时空分布特性。结果表明,研究区冬小麦-夏玉米连作多年平均作物有效降水量、作物需水量和灌溉需水量分别为389、736和347mm,丰水年、平水年和枯水年冬小麦-夏玉米连作灌溉需水量分别为321、382和423mm。冬小麦生育期灌溉需水量271～350mm,返青-拔节期、拔节-抽穗期和抽穗-成熟期灌溉需水量各占全生育期的26%、26%和29%;夏玉米全生育期灌溉需水量0～49mm,抽雄期和成熟期分别占全生育期的52%和48%。作物有效降水量空间分布,石家庄3县西高东低,邯郸2县西低东高;作物需水量石家庄3县高于邯郸2县;研究区灌溉需水量空间分布不均,大致呈带状分布。

Analysis of irrigation water requirement characteristics for wheat-maize continuous cropping in the five counties of Hebei Province

The data of five typical counties in Hebei Plain were collected to analyses the irrigation water requirement characteristics o f the wheat-maize continuous cropping system. Crop effective precipitation was calculated based on a modified SCS-CN model using precipitation, soil, crop conditions, among other factors. Crop water requirement was estimated by the Penman Monteith equation and crop coefficient method recommended by FAO . Besides, the spatial and temporal distribution characteristics of irrigation water requirements in different hydrological years were also analyzed. The results showed that the crop effective precipitation, water requirement and irrigation water requirement for the whole growing period of wheat-maize continuous cropping were 389, 736 and 347 mm, respectively, in the study area. T he ir rig atio n water requirement of wheat-maize continuouscropping in the wet , median, and dry water year was 321, 382 and 423 mm, respectively. The irrigation water requirement of winter wheat was 271-350 mm. The irrigation water requirement of the whole growth period was 26% , 26% and 29% respectively, in the period of turning green to jointing, jointing to heading and heading to maturity . The irrigation water requirement of summer maize was 0-49 mm accounting for 52% and 48% of the total fertility period, respectively. The spatial distribution of crop effective precipitation was decreased slowly from west to east in Shijiazhuang and increased gradually from west to east in Handan. T he water requirement in three counties of Shijiazhuang was slightly higher than those in two counties of Handan. The irrigation water requirement had a zonal distribution in the study area.