中文摘要：

在总结国内外关于水电站大坝下游总溶解气体（TDG）过饱和问题的研究现状的基础上，对紫坪铺坝下游河段的过饱和气体进行了原型观测，指出下泄流量与下游TDG饱和度有着较好的相关关系；河道水深是影响过饱和气体消减速率的重要因素；在同样单宽流量下，含沙水体比清水有更高的TDG饱和度。这一研究为更深入的开展高坝下游过饱和溶解气体的产生及消减过程理论研究提供了依据，对高坝下游水生生物保护具有重要作用。

英文摘要：

Based on the summarization of research on total dissolved gas（TDG） supersaturation, field observation of TDG downstream of Zipingpu dam was taken. The dissolved gas saturation levels were measured and recorded along transects distributing in 40 kilometers downstream of the Zipingpu dam. It shows that the depth and sand concentration of the river is an important factor affecting the desorption of TDG downstream of high dam. It provide a basis to find out the rule of desorption of dissolved gas supersaturation downstream of high dam, which is important for protecting fish in downstream of high dam.