Comparative study on the nitrite tidal cycle variation in the salt marsh area of Chongming between spring and summer

Twelve tides of water samples were collected from the leading edge of the salt marsh area in Chongming in the spring (May, 2007) and summer (June and July, 2007). The nitrite was analyzed by the ion-chromatographic analyzer. Monitoring studies show that the average nitrite concentration in the spring is more than in the summer, and the variation concentration of nitrite in the spring is greater intensity than in the summer. Based on this, we analyzed the vertical and tidal cycle variation in the spring and summer. There is complex relationship between nitrite and water environmental factors and flow velocity.