Spatiotemporal dynamics of irrigated cropland water use efficiency and driving factors in northwest China's Hexi Corridor  

作　　者：Dandan Du Bo Dong Rui Zhang Shiai Cui Guangrong Chen Fengfeng Du 

机构地区：[1]Dryland Agriculture Institute,Gansu Academy of Agricultural Sciences,Lanzhou 730070,China [2]Key Laboratory of Efcient Utilization of Water in Dry Farming of Gansu Province,Lanzhou 730070,China [3]Key Laboratory of Low-Carbon Green Agriculture in Northwestern China,Ministry of Agriculture and Rural Afairs,Yangling 712100,China [4]The Joint Key Laboratory of Ministry of Agriculture and Rural Afairs-Gansu Province for Crop Drought Resistance,Yield Increment and Rainwater Efcient Utilization On Rainfed Area,Lanzhou 730070,China [5]College of Water Conservancy and Hydropower Engineering,Gansu Agricultural University,Lanzhou 730070,China [6]Aerospace Information Research Institute,Chinese Academy of Sciences,Beijing 100101,China [7]Institute of Botany,Jiangsu Province and Chinese Academy of Sciences,Nanjing 210014,China

出　　处：《Ecological Processes》2024年第4期153-170,共18页生态过程(英文)

基　　金：supported by the National Key Research and Development Program of China(2021YFD190070406);the Key Research and Development Program of Gansu Province(20YF8NA107);Agricultural Science and Technology Special Project of Gansu Province(GNKJ-2021–32)

摘　　要：Background Agricultural irrigation is an important practice to safeguard crops against drought and enhance grain yield in arid regions.The Hexi Corridor,known as a classic arid region,faces signifcant pressure on agricultural production and food security due to the scarcity of water resources.There is an urgent need to investigate agricultural water use of the irrigated regions.Water use efciency(WUE),defned as the ratio of gross primary productivity(GPP)to actual evapotranspiration(ET),serves as a valuable indicator linking carbon assimilation and water loss.It enables the quantifcation of areas where water can be utilized more efectively.However,the long-term spatiotemporal dynamics of WUE and driving mechanism in the irrigated areas of the Hexi Corridor remain unclear.Results This study used GPP calculated by a light use efciency model(EF-LUE),ET estimated by an ETMonitor model and irrigated cropland maps across China(IrriMap_CN)to examine the spatiotemporal dynamics of irrigated cropland WUE and its controlling factors in the Hexi Corridor from 2001 to 2018.The results are as following:(1)The average annual WUE was approximately 1.34±0.38 g C kg^(−1) H_(2)O yr^(−1),with an increasing trend of 0.012 g C kg^(−1) H_(2)O yr^(−1),and faster growth observed during 2011–2018 compared to 2001–2010.(2)The contribution of GPP to WUE trends and WUE interannual variability(IAV)was greater than that of ET.(3)The dominant climatic factors of WUE IAV in the Hexi Corridor were SPEI,precipitation,and soil moisture.(4)The standardized Structural Equation Model(SEM),incorporating the relationship between WUE and factors such as water,energy,NDVI,and water-saving irrigation,explained 81%of the variation in irrigated cropland WUE.Here,biological factors(GPP and NDVI)were the primary factors infuencing WUE variability,and water-saving irrigation had a stronger indirect efect than climate factors(water and energy)on variation in WUE.Conclusions Our fndings ofer valuable theoretical insights into the mechanisms governin

关 键 词：Irrigated cropland Water use efficiency Hexi Corridor Interannual variability Dominant factor Driving mechanism 

分 类 号：S51[农业科学—作物学]