丰水期鄱阳湖水体中氮、磷含量分布特征

Distribution characteristic of nitrogen and phosphorus in Lake Poyang during high water period

以2011年7月份鄱阳湖实测数据为参考,对鄱阳湖丰水期总氮(TN)、总磷(TP)空间分布特征及其影响因素进行了分析,并就鄱阳湖氮、磷营养盐结构特征及其与叶绿素a的相关性进行了探讨.结果表明:鄱阳湖氮、磷含量已经达到了发生富营养化的条件,且TN含量呈现由东向西、由南向北逐渐降低的趋势;TP在几个主要的采砂区,尤其是南北湖交界处污染最严重.鄱阳湖以磷限制为主,氮污染相对比较严重,且氮、磷不是鄱阳湖藻类生长的限制性因素.TN同时受悬浮泥沙和水流作用的影响,在上游航道受水流影响较大,在入江水道则主要受陆源污染的影响.TP含量则主要受悬浮泥沙和采砂活动的影响,受水流作用影响相对较小.

Based on the measured concentration of total nitrogen （TN） and total phosphorus （TP） in Lake Poyang in July 2011, we analyzed the spatial distribution characteristic of TN, TP, and factors affecting them. The nutrient structure and the correlations among nitrogen, phosphorus and chlorophyll-a were discussed. The results show that： The concentration levels of nitrogen and phosphorus have already reached the threshold of eutrophication. TN content has a downward trend from the east part to the west part, and from the south part to the noah part, in Lake Poyang. TP contents in several dredging areas were the highest, especially in the border area between south lake and east lake. Phosphorus was limited in Lake Poyang. Comparatively speaking, nitrogen pollution was more serious, and the nitrogen and phosphorus were not the restricting factors of eutrophication. TN content was influ- enced by suspended sediment concentrations （SSC） as well as the water flow. It was mostly affected by the water flow in the up- stream channels which were largely influenced by the land-sourced pollutants. TP content was less affected by the water flow, but it was mainly influenced by the high SSCs and the dredging activities.