1967—2017年甘肃省小麦需水量和缺水量时空特征

基于甘肃省28个气象站点1967—2017年的逐日气象数据,采用Penman-Monteith公式和作物系数计算了小麦的需水量,结合美国农业部土壤保持局推荐的方法计算了有效降水量,进一步得出小麦缺水量,并分析了小麦需水量与缺水量的变化趋势和空间分布特征,探讨了小麦需水量影响因子重要程度。结果表明:1967—2017年甘肃省春、冬小麦全生育期的年平均需水量分别为517.03 mm和436.70 mm,年平均缺水量分别为468.24 mm和301.54 mm;在时间上,51 a来春小麦种植区内的需水量与缺水量整体上无明显的趋势变化,而冬小麦种植区内的需水量与缺水量整体上呈明显上升趋势;在空间上,春小麦种植区内需水量和缺水量大致由西北向东南递减,冬小麦种植区内的需水量和缺水量大致由西向东递减。甘肃省小麦生育期内日照时数和日平均气温是影响小麦需水量的主要因素。

Spatial and temporal characteristics of water requirement and water deficit of wheat in Gansu Province from 1967 to 2017

Using the daily meteorological data from 28 stations in Gansu Province,China from 1967 to 2017,the water required by wheat during its growing period was calculated with Penman-monteith formula.The effective precipitation in wheat’s whole growing period was calculated based on the method recommended by the USDA Soil Conservation Bureau.So we can get the water deficit of wheat during its life cycle.In addition,we analyzed the variation trend and spatial distribution characteristics of water requirement and water deficit of spring wheat and winter wheat as well as the affect factors of water requirement.The results showed that the annual average water requirement of spring wheat and winter wheat was 517.03 mm and 436.70 mm respectively and the annual average water deficit of spring wheat and winter wheat was 468.24 mm and 301.54 mm respectively in Gansu Province from 1967 to 2017.In the past 51 years,there was no significant change in the water requirement and water deficit in the spring wheat planting area,while there was a significant increase in the water requirement and water deficit in the winter wheat planting area.Spatially,the water requirement and water deficit in spring wheat planting area were decreased gradually from northwest to southeast,while the water requirement and water deficit in winter wheat planting area were decreased gradually from west to east.The sunshine hours and daily average temperature during the growth period of wheat in Gansu province are the main factors affecting the water requirement of wheat.