Measurement in situ of streambed hydraulic conductivities in the Platte River, Nebraska

In quantitative study of the interaction between the river water and groundwater,the hydraulic conductivities of streambed are very important parameters.The traditional methods,such as laboratory analysis,numerical model,and so on,can't provide the hydraulic conductivity in situ.The standipe test can measure the hydraulic conductivities in situ.In this study,the artificial gradient method and the natural gradiem method were used for measuring the hydraulic conductivities in vertical,horiwntal and oblique direcdons of streambed of the Platte River.The average vertical hydraulic conductivity for 10 test locations is 30.51 m/d.The horizontal hydraulic conductivity is about 97.2 m/d for the Platte River.The ratio of horiwntal and vertical hydraulic conductivities is about 3.The results indicate that the streambeds material is slightly anisotropy and heterogeneity in horiwntal direction.