Hydrological cycle simulation of irrigation district based on SWAT model

摘要

A distributed hydrological cycle model of irrigation district was developed based on the SWAT model (Soil and Water Assessment Tool) and the artificial-natural composite the hydrological cycle was considered. SWAT model was modified in the aspect of extraction of ditches, distributed subbasins and hydrologic response units, the calculation method of crop actual ET. The applicability of the model was validated in Fenhe irrigation district. The information on hydrology, weather and water use from 1996 to 2001 in the Fenhe irrigation district was used to simulate and analysis water balance. The sensitive parameters was estimated by Ens, RE and R2. The model was further validated with the monthly flow data from 2002 to 2006. The results showed that the simulated results of two monitoring points meet the estimated requirements. The RE value of the average annual runoff at Erba Station varied from -7.34% to 19.13% except a low RE value (-30.70%) in 2006. The RE of the average annual runoff at Yitang station was from -17.21% to 9.86% with an exceptional RE value (-21.13%) in 2003. From the monthly simulated results, the R2 of the monthly runoff at Erba and Yitang stations were 0.81 and 0.77, respectively. The Ens of monthly runoff were 0.72 and 0.65, respectively. Modified SWAT model was applicable for water balance simulation at Fenhe irrigation district.