Abstract: In this study, the effects of physical and chemical reactions of water on streambed permeability were deeply researched. The head down standpipe penetration test was used to test streambed vertical permeability coefficients, conducted at 98 test sites in the Weihe River Basin in Shaanxi Province, and the sediment samples were collected in-situ from the test sites, and they were tested with different aqueous solutions in laboratory. The results showed that the streambed vertical permeability coefficients tested with tap water were much higher than those tested with river water or nutrient solution. The streambed vertical permeability coefficient tested with nutrient solution was decreased at first and then increased. The effect of aqueous alkali on streambed vertical permeability coefficient was negative. Moreover, there was an extremely significant negative correlation between streambed vertical permeability coefficient and alkalinity of river water, but an extremely significant positive one with COD_Mn.

Key words: streambed, sediment, permeability coefficients, correlation analysis, the Weihe River of Shaanxi Province