小浪底水库对氨氮的水环境效应

采用1992年7月—2008年2月黄河干流潼关、三门峡、小浪底等水质监测断面氨氮逐月浓度监测数据,分析了小浪底水库运行前后潼关、三门峡、小浪底的氨氮年通量、年平均浓度变化情况,并结合潼关自动站与花园口自动站氨氮监测数据以及断面过水流量历史记录,研究了小浪底水库对氨氮的水环境效应。结果表明:小浪底水库运行后,就氨氮指标而言,小浪底坝下断面水质达标率大幅提高;从氨氮浓度波峰出现时间来看,小浪底断面氨氮浓度变化比潼关、三门峡断面滞后,滞后时间为30～60 d;小浪底水库下泄流量越大,有效库容越小,水库对氨氮的稀释作用越小,氨氮波峰滞后时间越短。

Water Environment Effect of the Xiaolangdi Reservoir on Ammonia Nitrogen

The attaining standards condition of ammonia nitrogen had been collected and analyzed by using the observed data of ammonia nitrogen concentration at the Tongguan,Sanmenxia and Xiaolangdi water quality monitoring sections from July 1992 to February 2008.Through analyzing the changes of the annual flux and the annual mean concentration of ammonia nitrogen at Tongguan,Sanmenxia,Xiaolangdi before and after the operation of Xiaolangdi Reservoir,combined with the monitoring data of ammonia nitrogen at Tongguan and Huayuankou automatic stations and the history analysis of section flow,the water environment effect of the Xiaolangdi Reservoir on the ammonia nitrogen was studied.The results show that a)as far as ammonia nitrogen indicator is concerned,after the running of Xiaolangdi Reservoir,the attainment rate of water quality of the section of the lower Xiaolangdi Dam has increased significantly;b) from the point of view of the occurrence time of wave crest of ammonia nitrogen concentration,it can be found that the change of ammonia nitrogen concentration of Xiaolangdi section lags than that of Tongguan and Sanmenxia sections,and the lag time is 30 to 60 days as a rule;c) it can be also found that the more discharge Xiaolangdi Reservoir releases,the effective storage will be smaller,the buffer effect of ammonia nitrogen will be less powerful,and the lag time of wave crest of ammonia nitrogen concentration will be shorter.