盐分对改进TDR测量土壤水分的影响及模型标定

The Effect of Salinity on Measurement of Soil Water Content Using Improved TDR and Calibration of Models

为实现高盐土壤含水率的精确测量,在室内进行了不同含水率和盐分组合的土柱试验,对TDR探头进行了改进,并利用改进后的TDR测量土壤含水率,同时对结果进行标定。结果表明,改进后的探头能够测量高盐土壤含水率,盐分对改进后TDR的影响表现出与未改进探头不同的规律。Evett模型拟合决定系数为0.835,改进探头含水率测量算法以Evett模型为宜。

To measure soil water content in high salinity soil accurately, indoor soil column experiments with different soil water contents and soil salt contents were conducted. The improved TDR was used to measure soil water content under different conditions and the results were calibrated. The results showed that the improved TDR could well work in higher salinity soil and the influence of salinity on the improved TDR differed from the unimproved TDR. Fitting decision coefficient of Evett model was 0. 835. It is recommended that Evett model should be used for the measurement algorithm of soil moisture by the improved probe.