Spatiotemporal variations in water requirement and irrigation water requirement of spring maize in Hexi Corridor

Jia Jianying; Fang Feng; Wang Heling; Zhao Hong; Zhou Zhongwen; Wang Ying; Yin Xuelian; Wang Fan; Huang Pengcheng; Ma Yulong; Zhang Yaxin

doi:10.13522/j.cnki.ggps.2025341

Abstract：[Objective]The Hexi Corridor is an arid agricultural region in Northwest China,with spring maize being the dominant crop and the largest water consumer.Affected by ongoing climate warming,meteorological conditions in the region have changed substantially over recent decades,exerting feedback effects on crop water consumption and influencing sustainable agricultural development.This paper analyses the spatiotemporal variations in water requirement and irrigation water requirement of spring maize under the influence of climate warming in this region.[Method]The analysis was based on daily meteorological data collected from 1971 to 2024 from 17 meteorological stations across the region,and spring maize growth traits observed from 1991 to 2024 from three field agrometeorological stations.The single crop coefficient method and ArcGIS spatial analysis technology were used to analyse the spatiotemporal variations in effective precipitation(Pe),crop water requirement(ET),and irrigation water requirement(Ir)of the crop.[Result]①Temporally,there was no significant variation in Pe during the spring maize growing season,with a regional average of 111.6 mm.Spatially,Pe increased from the northwest to the southeast.②The regional average ET was 682.7 mm.Temporally,ET decreased from 1971 to 1992 followed by a continuous increase from 1993 to 2024.Spatially,it decreased gradually from the northwest to the southeast.③The average Ir was 570.0 mm;it had increased at a rate of 10.4 mm per decade.Spatially,Ir decreased from the northwest to the southeast.④The irrigation demand index of the crop was high during its entire growth period.[Conclusion]As Northwest China undergoes warming and wetting,the temporal variation in spring maize ET is significantly correlated with mean wind speed and air temperature.Ir is positively correlated with air temperature,mean wind speed,and sunshine duration,and negatively correlated with effective precipitation.Climate warming has resulted in an increase in irrigation water demand of spring maize,further aggravating the imbalance between agricultural water supply and demand in the region.