Research on inversion of soil water dynamic parameters by field soil moisture content

The field soil moisture data under different vegetation and irrigation condition were accumulated by many irrigation experiments. The soil water dynamic parameters were acquired or improved by the parameters inversion method and making good use of these data. It was significance in monitoring and forecasting soil moisture and field water cycle. In this paper, according to the measured soil moisture of winter wheat from regreening to harvest in 2009 on Tianjin agricultural university agricultural water cycle experimental base, the parameter inversion model was established based on the objective function is the minimum of the relative error square sum between the simulated and measured value of the soil moisture content and the constraint is the diversification range of the water movement parameters acquired from the documents. The water transport parameters of soil characteristic in experimental site are acquired by use of the interior point method and model method. The results showed that the simulation accuracy of the field soil moisture dynamic is significantly improved by the parameter inversion. The changed initial value and step scaling factor are in favor of improving parameter optimization results.