Calculation framework for agricultural irrigation water consumption in multi-source irrigation systems

摘要

This study proposed a calculation framework to reasonably and effectively calculate the agricultural irrigation water consumption (AIWC) and reused irrigation return flow (IRFr) in multi-source irrigation systems based on the modified Soil and Water Assessment Tool (SWAT). The calculation framework was applied in the Yangshudang (YSD) watershed in southern China over the years. Results showed that total AIWC and IRFr of the irrigation system increased as the degree of drought increased. The improved total AIWC (AIWC(new,g)), which considered the reuse of return flow, is less than the traditional total AIWC (AIWC(o,g)). In addition to the backbone water source of the Zhanghe Reservoir, 44.54% of the AIWC(o,g) of the YSD watershed came from ponds inside the YSD watershed under multiyear average conditions. The IRFr accounted for 6.49% of the AIWC(o,g), and the AIWC(new,g) accounted for 93.51% of the AIWC(o,g). For accuracy and management, this calculation framework and improved AIWC are suggested to be used in the multi-source irrigation systems.