Variation characteristics of total dissolved gas in water during the operation of the phase I of the Datengxia project
When the dam is discharged,a large amount of air is absorbed into the water,resulting in supersaturation of total dissolved gas(TDG),and its negative ecological impact will persist for a certain distance in the downstream river,increasing the risk of bubble disease in fish.To study the change characteristics of TDG during the operation of Phase I of the Datengxia Project,continuous monitoring of TDG was carried out.The results showed that the phenomenon of TDG saturation in the water body of Dtengxia reservoir is not obvious,which had little effect on the downstream water ecology,and the TDG increment caused by dam crossing had a good linear relationship with the discharge of Dtengxia reservoir.When the daily average discharge was below 6 000 m3/s,the concentration of TDG in the downstream fluctuated around 100%,and there was no supersaturation problem.When the daily average discharge rate reached 8 000 m3/s or higher,a high TDG concentration of more than 120%was detected in the downstream water body but fell below the standard limit of 110%20 km below the dam,which had little impact on the downstream ecology.The merging of Yujiang tributaries had a strong promoting effect on the dispersion of high-concentration TDG in the mainstream water body.
dam dischargetotal dissolved gassupersaturationconfluencerelease coefficient
万方数据
维普
