Accuracy evaluation of simulating point source infiltration in field and water redistribution based on Hydrus- 3D model
ZHOU Guang-lin;WANG Quan-jiu;LI Yun;SU Li-jun;Xi'an University of Technology;
Under the drip irrigation condition,the water infiltration and redistribution process is an important content of evaluating irrigation efficiency. Through the Hydrus- 3D model,has simulated the single point source infiltration and redistribution,and verified by the measured information of the field experiments. Tthe results showed tha: Using the Hydrus- 3D software to set up the model,it can be good simulated the single point source infiltration,horizontal wetting front diffusion process and the distribution situation of soil water in soil profile. The error between simulated and measured values of the distance for the horizontal wetting front was reached the maximum when the end of irrigation,also the bigger of the trickle discharge,the more obvious of the error. Among them the maximal absolute error was 4. 6 cm,the maximal relative error was 0. 167 and the R2 was more than 0. 95. The P value in F-test was more than 0. 05 and RMSE was less than 2. 1. The simulated soil water content distribution was quiet consistent with the measured values,the R2 of simulated and measured values was above 0. 90,the P value in F-test was more than 0. 05 and RMSE was less than 0. 07. The simulated and measured soil wetting range was higher degree of agreement. After end of irrigation for 20 hours,the simulated water content distribution in soil profile was in agreement with the measured values,the R2 between simulated and measured values was between 0. 575~ 0. 652,the P value in F-test was more than 0. 05 and RMSE was about 0. 013. Whole profile in double pointsources interference area,the R2 of simulated and measured values was above 0. 526,the P value in F-test was more than 0. 05,RMSE was total less than 0. 01. The simulated results were quite good,it explained that the situations of soil water redistribution can be simulated by the Hydrus3 D model.