239 / 2024-02-28 15:16:16

Water Use Efficiency Calculation of Typical Crops in Three Gorges Reservoir Area Based on HYDRUS Model

water use efficiency,typical crops,HYDRUS,Three Gorges Reservoir area

Subtheme 2: Integrated Water Resources Management > Topic 3: Optimal allocation and effective utilization of Water Resources

How to promote the agricultural water use effectiveness has been a hot topic concerned by agriculture and hydrology theorists and practitioners for a long time. As an important index of agricultural water amnagement, the water use efficiency is the key point in the area of water-saving agriculture research. A high level of water use efficiency is critical to the sustainable and stable development of agriculture under the situation of water shortage. In this study, the Wangjiaqiao watershed in Zigui County which is located in the Three Gorges Reservoir area is taken as the research area, and the typical crops in the Three Gorges Reservoir area including wheat, soybean and corn are taken as the research objects. Based on the field observation of runoff plots planted with different crops, a one-dimensional soil water vertical transport model coupled with water absorption by crop roots is established by the HYDRUS-1D model. The soil and plant hydraulic parameters in the model are calibrated based on the field observation results. The water use efficiencies of the above three typical crops, wheat, soybean and corn were calculated by the calibrated model. The results indicate that the HYDRUS-1D model can well simulate soil and plant hydrological process, and the soil water in the root zone is mainly controlled by rainfall and crop growth period. The calculated water use efficiencies of wheat and soybean are 0.91~1.57kg/m³ and 0.51~0.63kg/m³ respectively, and that of maize was 5.11kg/m³. By comparing the water use efficiency with precipitation in different years for the same crop, the smaller the precipitation, the greater the water use efficiency, which indicates that insufficient precipitation is conducive to improving the crop water use efficiency. Results of the present study would provide important reference for agricultural water saving and water resources efficient utilization in the Three Gorges Reservoir area.