title: Simulating Crop Evapotranspiration Response under Different Planting Scenarios by Modified SWAT Model in an Irrigation District, Northwest China.
abstract: Modelling crop evapotranspiration (ET) response to different planting scenarios in an irrigation district plays a significant role in optimizing crop planting patterns, resolving agricultural water scarcity and facilitating the sustainable use of water resources. In this study, the SWAT model was improved by transforming the evapotranspiration module. Then, the improved model was applied in Qingyuan Irrigation District of northwest China as a case study. Land use, soil, meteorology, irrigation scheduling and crop coefficient were considered as input data, and the irrigation district was divided into subdivisions based on the DEM and local canal systems. On the basis of model calibration and verification, the improved model showed better simulation efficiency than did the original model. Therefore, the improved model was used to simulate the crop evapotranspiration response under different planting scenarios in the irrigation district. Results indicated that crop evapotranspiration decreased by 2.94% and 6.01% under the scenarios of reducing the planting proportion of spring wheat (scenario 1) and summer maize (scenario 2) by keeping the total cultivated area unchanged. However, the total net output values presented an opposite trend under different scenarios. The values decreased by 3.28% under scenario 1, while it increased by 7.79% under scenario 2, compared with the current situation. This study presents a novel method to estimate crop evapotranspiration response under different planting scenarios using the SWAT model, and makes recommendations for strategic agricultural water management planning for the rational utilization of water resources and development of local economy by studying the impact of planting scenario changes on crop evapotranspiration and output values in the irrigation district of northwest China.
authors.affiliation: Department of Water Resources and Civil Engineering, China Agricultural University, Beijing, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Liu
authors.affiliation: Department of Water Resources and Civil Engineering, China Agricultural University, Beijing, China.
authors.forename: Sufen
authors.initials: S
authors.lastname: Wang
authors.affiliation: Department of Water Resources and Civil Engineering, China Agricultural University, Beijing, China.
authors.forename: Han
authors.initials: H
authors.lastname: Xue
authors.affiliation: Department of Biological & Agricultural Engineering, Texas A & M University, College Station, Texas, United States of America.
authors.forename: Vijay P
authors.initials: VP
authors.lastname: Singh
mesh_terms: D057914:Agricultural Irrigation / Q000379:methods*; D000383:Agriculture / Q000379:methods; D002681:China; D018556:Crops, Agricultural / Q000254:growth & development*; D008962:Models, Theoretical; D014908:Triticum / Q000254:growth & development*; D062066:Water Resources; D003313:Zea mays / Q000254:growth & development*