| In order to scientifically manage planting,reduce the consumption of water resources in Beijing-Tianjin-Hebei by crop planting,and realize the efficient utilization of agricultural water resources,this paper takes Beijing-Tianjin-Hebei as the research area,and based on the AquaCrop,changes the traditional calling method of GeoSim in QGIS to realize winter wheat Batch Simulation of Summer Maize Yield and Irrigation Water Requirement.On this basis,the water scarcity footprint of crops is calculated,which provides a theoretical basis for the evaluation of regional water saving policies at a refined scale.The main contents and research results are as follows:(1)Aiming at the problem of crop growth simulation,based on the experimental data of field positioning,the parameters of the AquaCrop were adjusted and verified,and the key parameters of the model were calibrated using the OTA method.The R2,RMSE,EF,d between the simulated and measured values of winter wheat and summer maize canopy coverage are 0.9611,6.6%,0.91,0.98 and 0.9571,5.5%,0.95,0.99;The four precision evaluation indexes between the simulated and measured values of aboveground dry biomass of winter wheat and summer maize are 0.9661,0.8 ton/ha,0.93,0.98 and 0.9087,1.3 ton/ha,0.90,0.98;The R2,RMSE,EF,and d between the simulated and measured values of soil water content in winter wheat were 0.9706,3.7 mm,0.93,and 0.98.The results show that the AquaCrop has high accuracy in simulating winter wheat and summer maize canopy coverage,aboveground dry biomass and soil water content,and the model has strong applicability to the simulation of winter wheat and summer maize yield and irrigation water consumption.(2)In view of the tediousness of manually entering the model input parameters,the GeoSim tool was developed.This paper changes the way that the traditional GeoSim tool drives the AquaCrop model,creates a template file based on the model continuous cropping project file,and converts the calling data into the file name of calling meteorological,soil and crop parameters,which speeds up the access speed of information and simplifies the preparation for model operation.Using the GeoSim tool to drive the AquaCrop to simulate the yield and irrigation water consumption of winter wheat and summer maize in 2009,2014,and 2019 only took 14 minutes and 15 seconds,which is much lower than the time spent using the model plug-in program.The GeoSim tool scales geographic information from multiple data sources onto a base-layer polygon,reducing the time it takes to generate project files and managing output files,and speed up model simulation.The results show the effectiveness and applicability of the tool for AquaCrop simulations,and the simulation results can be visualized in space,extending the use of the AquaCrop model to the time-space analysis scale.(3)From the perspective of water footprint,the water footprint is closely combined with the water resources system to calculate the water scarcity footprint of two crops,winter wheat and summer maize,to provide a theoretical basis for the evaluation of regional water conservation policies at a refined scale.The results show that from 2009 to 2019,the yields of winter wheat and summer maize in the Beijing-Tianjin-Hebei region have increased.The total output growth rate of winter wheat in the Beijing-Tianjin-Hebei region was about 25.08%,and that of summer corn was about 37.39%;the total WSF of winter wheat showed a downward trend,and the total WSF of summer corn showed an upward trend.The main areas showing an increase are similar to the spatial variation in crop yields.It is recommended to further reduce the crop planting area in Daming County,Ningjin County,Dingzhou City and other areas,increase the source of water resources,and try to increase the effective irrigation area of crops to increase the efficiency of irrigation water use.Therefore,the analyses conducted in this study can optimize crop cultivation and provide information on the spatial distribution of water scarcity that can help identify areas where sustainability measures are most needed. |
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