水动力对沉积物-水界面氧通量产生机制的影响

选取三峡库区支流御临河为研究对象，测量了5个水动力条件（平均流速为0.00，0.03，0.07，0.12，0.20m/s）下沉积物-水界面（SWI）氧通量的变化及水动力条件对SWI氧通量产生机制的影响.结果表明，随着平均流速的升高，SWI氧通量增加，由0.00m/s时的1.197mmol/（m²·h）增加为0.20m/s时的43.981mmol/（m²·h），溶解氧穿透深度增加，氧进入沉积物更深处并被微生物和还原性物质所利用，沉积物耗氧量上升；当平均流速较低时，沉积物耗氧量以生物耗氧量为主，在0.00m/s与0.03m/s时生物耗氧量为氧通量的85.3%与57.7%；当水体平均流速较高，化学耗氧量与其他耗氧量中的化学过程耗氧量在氧通量中的比重逐步提高.

The influence of hydrodynamic conditions on the generation mechanism of SWI oxygen flux

Yulin river, a tributary of the Three Gorges reservoir area, was selected as the research object. The change of SWI oxygen flux under 5hydrodynamic conditions (average velocity 0.00, 0.03, 0.07, 0.12 and 0.20m/s) and the influence of hydrodynamic conditions on the generation mechanism of SWI oxygen flux were measured. As the average velocity increases, SWI oxygen flux increased from 1.197mmol/(m²·h) at 0.00m/s to 43.981mmol/(m²·h) at 0.20m/s. The penetration depth of dissolved oxygen also increased. Oxygen entered deeper sediments and got used by microorganisms and reducing substances thus the oxygen consumption increased. In addition, when the average velocity was low, the oxygen consumption of sediments was dominated by biological oxygen consumption. At 0.00m/s and 0.03m/s, the biological oxygen consumption accounted for 85.3% and 57.7% of the oxygen flux. While when the average velocity was high, the proportion of Chemical oxygen consumption and other oxygen consumption in the chemical process in oxygen flux gradually increased.